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The Magnetosphere

    Topics Include :-

  1. What Powers the Earth's Magnetic Field?
  2. Sacred Geometry, the Pyramid and the Moon/Earth Ratio
  3. Vortex Size Given in Oahspe
  4. Magnetospheres
  5. Coupling
  6. Ionosphere
  7. Magnetic Field Reconnection
  8. The Ring Current
  9. The Van Allen Belt
  10. The Io Plasma Torus

What Powers the Earth's Magnetic Field?

There is a gap in knowledge of the cause of earths rotation, magnetic field and electric belts.
The electric currents within the Earth require extremely sensitive instrumentation. How can such small hard to detect currents generate such an awesome magnetic field?
What is causing these Earth's currents? Where is the power coming from? In all cases, these currents would require power or energy to sustain themselves. Some scientists believe the power is coming from the kinetic energy stored in the rotational mass of the Earth. If this is true, then how much kinetic energy is required to support a magnetic moment as large as the Earth?
Based on a study by G. D. Gibson and P. H. Roberts at University of Newcastle upon Tyne; assuming a radius of the size of the Earth, the magnetic permeability of the Earth's materials and electrical conductivity of those materials the decay time of a conducting sphere is about 15,000 years.
The Earth's currents, like the magnetic field, require a force to sustain them. This force must be much grander in scale than the Earth's rotational momentum.
The Dynamo Theory is based on motion. The rotation of the body generates the necessary forces to create the generation of a magnetic field. Now, if this were true, then Mercury which rotates very slowly compared to the Earth and Mars, should have little or no magnetic field. Mars which rotates at close to the speed of Earth should have close to the same magnetic field as Earth. This is not the case. Mars has a very small magnetic field and Mercury has a strong magnetic field.

Within the plasma sheet are currents of electrical particles flowing perpendicular to the plane of the Sun and Earth. There are two currents, one in the northern sector and one in the southern sector of the plasma sheet. Between the two currents is a neutral sheet where current flows together. The potentials of 1 to 8 thousand volts are commonly present.
Areas as the Van Allen radiation belts potentials can be as high as 100 million volts. Because these are high currents and are of astronomical size in a high resistance environment P = I2 × R, the energy required to support the currents is astronomical. The energy of the proportions such that if applied to stop the Earth, it could bring the Earth to a stand still within one revolution about the Sun.

Plasma Fountain

Plasma Fountain
This figure depicts the oxygen, helium, and hydrogen ions that gush into space from regions near the Earth's poles. The faint yellow gas shown above the north pole represents gas lost from Earth into space; the green gas is the aurora borealis-or plasma energy pouring back into the atmosphere

The oahspe tells us:
7. Things fall not to the earth because of the magnetism therein, but they are driven toward the center of the vortex, by the power of the vortex.
8. The greater diameter of the vortex is east and west; the lesser diameter north and south, with an inclination and oscillation relatively like the earth.
9. The name of the force of the vortex is called vortexya, that is, positive force, because it is arbitrary and exerteth east and west. As in the case of a wheel turning on its axis, its force will be at right angles with its axis, the extreme center of which will be no force.
10. For which reason the north and south line of the earth's vortex is called the m'vortexya, or negative force, for it is the subject of the other. As a whirlwind gathereth up straw and dust, which travel toward the center of the whirlwind, and to the poles thereof, even so do corporeal substances incline to approach the poles of the earth's vortex. Which may be proved by poising a magnetized needle.
15. The positive force of the vortex is from the external toward the internal; and the negative force of the vortex is toward the poles, and in the ascendant toward the pole external from the sun center.
16. Whereof it may be said the force of the vortex is toward its own center, but turneth at the center and escapeth outward at the north pole. As one may draw a line from the east to the center of the earth, thence in a right angle due north, which would be the current of the vortex until the center were filled with a corporeal body. After which the same power applieth, and is all one power, although for convenience called positive and negative.

Book Of Cosmogony And Prophecy Ch I.
A Birkeland current flows earthwards down the morning side of the Earth's ionosphere, around the polar regions, and spacewards up the evening side of the ionosphere. These Birkeland currents are now sometimes called auroral electrojets.
Birkeland currents are also one of a class of plasma phenonena called a z-pinch, so named because the azimuthal magnetic fields produced by the current pinches the current into a filamentary cable. This can also twist, producing a helical pinch that spirals like a twisted or braided rope.
Electrons moving along a Birkeland current may be accelerated by a plasma double layer. If the resulting electrons approach relativistic velocities (ie. the speed of light) they may subsequently produce a Bennett pinch, which in a magnetic field will spiral and emit synchrotron radiation that includes radio, optical (ie. light), x-rays, and gamma rays.

The best magnetic field theory I've found tells us:
"The earth's mantle covers a fluid core which itself has a solid core. The fluid layer has a ferrous material. It rotates in the electrostatic field of the sun, which causes eddy currents in the core. This large rotating electric current creates a magnetic field which is at right angles to itself, and because the current flow is around the equator this magnetic field points towards the poles of the earth's axis."

Sacred Geometry, the Pyramid and the Moon/Earth Ratio

The Golden Mean, sometimes referred to as the The Sacred Cut or The Phi (Φ) Ratio, has connections with Galactic and Atomic mathematics, is revealed in ancient temples and pyramids and in the nesting of the 5 Platonic Solids. It is encrypted in the Fibonacci Sequence and in the counter-rotating fields or spirals of the sunflower and pinecones.


In the diagram (left), the big triangle is the same proportion and angle of the Great Pyramid, with its base angles at 51 degrees 51 minutes. If you bisect this triangle and assign a value of 1 to each base, then the hypotenuse (the side opposite the right angle) equals Φ (1.618..) and the perpendicular side equals the square root of Φ.
A circle drawn with it's centre and diameter the same as the base of the large triangle to represent the circumference of the earth. A square is then drawn to touch the outside of the earth circle. A second circle is then drawn around the first one, with its circumference equal to the perimeter of the square. (The squaring of the circle.)
This new circle will actually pass exactly through the apex of the pyramid. A circle drawn with its centre at the apex of the pyramid and its radius just long enough to touch the earth circle, will have the circumference of the moon!

A Verification

The Great Pyramid was originally 481 feet, five inches tall (146.7 meters, or 5,777 inches) and measured 755 feet (230.4 meters or 9060 inches) along its sides.

17. The width of the inclined plane was the same as the width of the temple, but the whole length of the inclined plane was four hundred and forty lengths (of a man).

Book Of Wars Against Jehovih Ch XLIX
440 lenghths = approx. 30,800 inches
angle of incline = asin (5777 ÷ 30,800) = 10.8° maximum (at top of pyramid)

It is said that π (3.1415927) is equal to two times one side of the Great Pyramid base divided by the height
Two times a side ÷ height = 230 meters × 2 ÷ 146.7 meters = 3.1356
Or in inches:
Two times a side ÷ height = 9060 inches × 2 ÷ 5,777 inches = 3.1366

For the pyramid in the diagram:
Two times a side ÷ height = 2 × 2 ÷ (square root of Φ [1.618]) = 4 ÷ 1.2720 = 3.1446
π actually = 3.1415927
So sacred geometry is not exact in this case.

Here's a different version:
(I cant remember where I got these figures from)
The perimeter of the base divided by twice the height = π to 5 decimal places {9131 × 4 ÷ (5813 × 2) = 3.141579...}
9060 × 4 ÷ (5777 × 2) = 3.136576

The ancient Egyptians had, through the use of tangential corridors, obelisks and light wells, the ability to divide a year in half or quarters with an accuracy of plus or minus 15 seconds.

The Earth's diameter = 7926 miles
The Moon's diameter = 2,160 miles
Root Φ = (7926 miles + 2,160 miles) ÷ 2 = 10,086 ÷ 2 = 5043 miles
Earth's diameter ÷ 2 = 7926 ÷ 2 = 3963 miles

The Earth and Moon's sizes are related to a "Golden Right Triangle" (ie. one which has sides in proportion to Φ as shown).
Tan of Pyramid angle = Root Φ ÷ (Earth's diameter ÷ 2) = 5043 miles ÷ 3963 miles = 1.2725
Artan of 1.2725 = 51.83 degrees
which also happens to be the angle of the Great Pyramid.

Extra Information

The Sun and Earth are similar in that the space around the Earth is hotter than the surface of the Earth.
Jupiter gives off twice as much heat as it absorbs from the Sun. It also has an extremely strong magnetic field.
Satellites will retain the same tilt even if jolted from their orbit (similar to a gyroscope), although the process may induce a wobble of the spin axis.
Several characteristics of the Earth-Moon system distinguish it from the satellite systems of most other planets in the Solar System, including the unusually large relative size of the Moon, its great orbital distance from Earth, and the fact that the Moon's path around the Sun is always concave to the Sun, like that of the Earth (but unlike that of most other satellites in the Solar System). As a result, some observers hold that the Earth-Moon system is a double planet rather than a planet with a satellite.

When viewed from Earth's North pole the Earth and Moon rotate counter-clockwise about their axes; the Moon orbits Earth counter-clockwise and Earth orbits the Sun counter-clockwise.
Earth and Moon orbit about their barycenter, or common center of mass, which lies about 2,920 miles from Earth's center (about 3/4 of the way to the surface). Since the barycenter is located below the Earth's surface, Earth's motion is described as a "wobble".
The Moon's synchronous rotation (the same face is turned to the Earth at all times) is only true on average because the Moon's orbit has definite eccentricity. As a result it does not orbit at a constant speed. However it rotates at a constant speed. When the Moon is at its perigee, its rotation is slower than its orbital motion, and this allows us to see up to an extra eight degrees of longitude of its East (right) side.
Conversely, when the Moon reaches its apogee, its rotation is faster than its orbital motion and reveals another eight degrees of longitude of its West (left) side. This is called longitudinal libration.
The line of apsides is the major axis of an elliptical orbit.

The lunar orbital inclination (which varies between 28.60° and 18.30°) is measured with respect to the Earth's equatorial plane. The Moon moves about 13° eastwards against the background of stars as a consequence of its revolution around the Earth.
The plane of the lunar orbit maintains an inclination of 5.145 396° with respect to the ecliptic (the orbital plane of the Earth around the Sun).
Lunar libration
Because the lunar orbit is also inclined to the Earth's equator, the Moon seems to oscillate up and down (as a person's head does when nodding) as it moves in celestial latitude (declination). This is called latitudinal libration and reveals the Moon's polar zones over about seven degrees of latitude.
The lunar Axial tilt is measured with respect to the normal to the Moon's orbital plane, compared with which it varies from between 3.60° and 6.69°. This means that sometimes the Moon's North Pole is tilted towards the Earth and sometimes tilted away.

lunar libration
The lunar axis, however, maintains an inclination of 1.5424° with respect to the normal of the ecliptic.
Because the Moon is only at about 60 Earth radii distance, an observer at the equator who observes the Moon throughout the night moves by an Earth diameter sideways. This is diurnal libration and reveals about one degree's worth of lunar longitude.
The intersection of the lunar orbital plane with the ecliptic precesses clockwise in 6793.5 days (18.5996 years).
During that period, the lunar orbital plane thus sees its inclination with respect to the Earth's equator (itself inclined 23.45° to the ecliptic) vary between 23.45° + 5.15° = 28.60° and 23.45° - 5.15° = 18.30°.
Simultaneously, the axis of lunar rotation sees its tilt with respect to the Moon's orbital plane vary between 5.15° + 1.54° = 6.69° and 5.15° - 1.54° = 3.60°. Note that the Earth's tilt reacts to this process and itself varies by 0.002 56° on either side of its mean value; this is called nutation.

The points where the Moon's orbit crosses the ecliptic are called the "lunar nodes": the North (or ascending) node is where the Moon crosses to the North of the ecliptic; the South (or descending) node where it crosses to the South. Solar eclipses occur when a node coincides with the new Moon; lunar eclipses when a node coincides with the full Moon.
Roughly once every 18.6 years, the declination of the Moon reaches a maximum, which is called the lunar standstill.

Oahspe says:
That the periphery of the vortex is undulated ; and the extent of its undulation can be determined by the minimum and maximum distance of the satellite from its planet.

[It might be thought that this effect is latitudinal libration, yet this is apparent (like the sun that appears to go around the earth) whereas the undulations are given here as physically real.]

14. In consequence of this discrepancy, the lens power of the vortex of the earth varies constantly, even daily, monthly and yearly. Nevertheless, the sum of heat and cold and the sum of light and darkness are nearly the same, one generation with another. This was, by the ancient prophets, called the FIRST RULE IN PROPHECY. This was again subdivided by three, into eleven years, whereof it was found that one eleven years nearly corresponded with another eleven years. This was the SECOND RULE IN PROPHECY. The THIRD RULE was NINETY- NINE YEARS, whereto was added one year.
15. In the case of the tides, a still further allowance of six years was found necessary to two hundred; but in the succeeding four hundred years a deduction was required of five years. Whereupon the moon's time was eighteen years.
16. As the lens power loseth by flattening the vortex, and increaseth by rounding the vortex, it will be observed that the position of the moon's vortex relatively to the earth's, is a fair conclusion as to the times of ebb and flood tide.


[The equivalent science explaination seems to be:
The tidal flow period, but not the phase, is synchronized to the Moon's orbit around Earth.

Two tidal bulges, one in the direction of the Moon, and one in the opposite direction (first figure) form as a result of the tidal forces caused by the moon's gravitation. Since the Earth spins faster than the Moon moves around it, the tidal bulges are dragged along with the Earth's surface faster than the Moon moves, and move "in front of the Moon" (next figure). Because of this, the Earth's gravitational pull on the Moon has a component in the Moon's "forward" direction with respect to its orbit. Because the Moon is accelerated in forward direction, it moves to a higher orbit. As a result, the distance between the Earth and Moon increases, and the Earth's spin slows down (last figure).]

In periods of thirty-three years, therefore, tables can be constructed expressing very nearly the variations of vortexya for every day in the year, and to prophesy correctly as to the winters and summers, so far as light and darkness, and heat and cold, are concerned. This flattening and rounding of the vortexian lens of the earth is one cause of the wonderful differences between the heat of one summer compared with another, and of the difference in the coldness of winters, as compared with one another. Of these also, tables can be made. Winter tables made by the ancients were based on periods of six hundred and sixty-six years, and were called SATAN'S TABLES, or the TIMES OF THE BEAST. Tables made on such a basis are superior to calculations made on the relative position of the moon.
17. But where they have prophesied ebb and flood tide to be caused by certain positions of the moon, they have erred in suffering themselves to ignorantly believe the cause lay with the moon.

Book of Cosmogony and Prophecy Ch III:13

Vortex Size Given in Oahspe

Tae ... proved that the attraction of any corporeal world does not exceed seven of its own diameters [14 RE], and many of them less than two diameters. He also measured the satellites and their distances from their central corpor, and he perceived that the diameters of the vortices could be determined by the loss or gain in the velocity of the satellites.
23. Where vortices had matured in form, he called them wark, as they had been called among the ancients, and the wark of the earth was one million five hundred and four thousand miles
[1,504,000] in circumference ...
Book of Knowlege 4.22
Earth and Atmospherea Jehovih has said: Around My corporeal worlds I placed atmospherea; for, as the earth and other corporeal worlds provide a womb for the spirit of man, so have I made the substance of atmospherea to be a womb for the souls of men. And Jehovih made the atmosphere of the earth with a circumference of 1,504,000 miles, with the earth floating in the center of it.
God's Book of Ben Ch 1. Plate 23 Earth and atmosphere

Ca = π × Da (Earth's atmosphere diameter)                       Da = Ca ÷ π
Therefore the Earth's atmosphere diameter (Da) = 1,504,000 ÷ 3.1416 = 478,738 miles broad
Ra = Da ÷ 2 = 239,369 miles         earth's radius (RE) = 3959 miles
Therefore the Earth's atmosphere is 239,369 ÷ 3959 = 60.462 RE from the Earth's center.

Earth and Atmospherea, (as seen through spiritual eyes). The earth is the black center, and the surrounding swirled gradations of gray, her atmospherea. The rings symbolize plateaus; the outer rim, Chinvat.
"The vortex turneth the earth on its axis, with its own axial motion.
Consequently the outer part of the vortex hath greater velocity than near the earth's surface, which hath an axial motion of one thousand miles an hour."
Book of Cosmogony and Prophecy Ch I:3

The Earth's diameter = 7926 miles
The formula for a circumference of a circle (C) is C = π × D
Where D = diameter = 2 × radius and π = 3.14159265
C = π × D = π × Earth's diameter = 3.14159265 × 7,926 = 24,900 miles
The formula for velocity (V) is V = distance ÷ time
Velocity near the earth's surface = 24,900 miles ÷ 24 hours = 1,038 miles/hr [approximely 1,000 miles an hour]

I have noticed that there are discrepancies of the 1882 Oahspe Edition with the 1891 Edition in Cosmogony and Prophecy Ch. 1 verse 4 and 5

My English Oahspe (the 1891 Edition which has a few alterations made by Dr. Newbrough) says:
"The moon hath a vortex surrounding it also, which hath a rotation axially once a month, but being an open vortex turneth not the moon. All vortices do not lay in contact with the planet, in which case it is called a dead planet. The SEMI DIAMETER OF THE moon's vortex is ten times the moon's diameter, and THE SEMI DIAMETER OF THE earth's vortex thirty times the earth's diameter".

Book of Cosmogony and Prophecy Ch I:4

Semi diameter of the earth's vortex = 30 × 7,926 miles = 237,780 miles
So the earth's vortex would be 237,780 × 2 = 475,560 miles broad.

The Moon's diameter = 2,160 miles
Semi diameter of the moon's vortex is ten times it's diameter = 10 × 2,160 miles = 21,600 miles.

But the 1882 Oahspe Edition says:
"The moon's vortex is ten times the moon's diameter, and the earth's vortex thirty times the earth's diameter."

Then the earth's vortex is 237,780 miles broad and the moon's vortex is 21,600 miles broad.

Science says:
"The distance (which can vary) from the magnetosphere's boundary on the side facing the Sun to the Earth's center is about 43,496 miles (10-12 Earth radii or RE, where 1 RE=3960 miles). The magnetopause (flanks 15 RE abreast of the Earth) is roughly bullet shaped, and on the night side (in the magnetotail) it approachs a cylinder shape with a radius 20-25 RE
[another source said 25-30 RE].
The tail region stretches well past 200 RE, and the way it ends is not known. The neutral gas envelope of Earth (geocorona) continues to about 4-5 RE, with diminishing density and minimal interaction with the plasmas of the magnetosphere. So does the upwards extension of the ionosphere, known as the plasmasphere.
The moon's average distance from the Earth is about 60 RE (30 diameters)"

Therefore the diameter of the widest part of the magnetosphere (cylinder radius) is 30 RE × 2 = 30 diameters ie., one could think this was the earth's vortex size as given in the 1882 Oahspe Edition, which by coincidence is about half way to the moon.

There are various figures given for the average distance between the moon and the earth. These range from 238,857 miles to 238,897 miles. [This would be center-to-center.]
I will use 238,896 miles, which is appoximately:-
238,896 miles ÷ 7,926 miles (earth's diameter) = 30.14 or 30 diameters

The Moon moves around the Earth in an elliptical orbit (eccentricity =0.0554), so the distance between the Earth and Moon varies from 222,756 miles at perigee, or closest approach to 254,186 miles at apogee, its farthest point [another source gives 225,740 and 251,970).

So the 1882 Edition figure is only half way to the moon. If the 1882 Edition had have said " the SEMI DIAMETER (or radius) of the earth's vortex is thirty times the earth's diameter", then the earth's vortex would overlap the moon's vortex, and reach the moon. This suggests that this is how the 1891 Edition revisionists saw the vortex to be.

In addition, Oahspe repeatedly says, when referring to Chinvat (the bridge on the boundary of the earth's vortex), that it is just beyond the orbit of the moon.

Also the 1891 Edition says:
"The outer rim, forty-two thousand miles broad, of the MOON'S vortex, hath a revolution axially with the earth once a month. The swiftest part of the earth's vortex is therefore about fifteen thousand miles this side of the orbit of the moon."

Book of Cosmogony and Prophecy Ch I:5

The 1882 Edition says:
"The outer rim, forty-two thousand miles broad, of the EARTH'S vortex, hath a revolution axially with the earth once a month. "
[The "earth's vortex" is replaced by the "moon's vortex".]

If the earth's vortex is forty-two thousand miles broad then it can't be 30 (237,780 miles broad) but 5.3 times its diameter according to the 1882 Edition Oahspe.
[This is 10.6 RE (Earth Radii) or the known size of the Earth's magnetosphere on the Sun's side. This is a little wider that the outer Van Allen Belt (3 - 9 RE). Away from the sun the tail of the magnetospere is about 10 times longer (395,300 miles) which is greater than the moon's orbit. (238,849 miles). This leaves us with a puzzle. The magnetospere's tail does not follow the moon around, but always points away from the sun like a comet.]

Ruth has interpreted the 1882 Edition verse that says:
"The outer rim, forty-two thousand miles broad, of the earth's vortex, hath a revolution axially with the earth once a month. The swiftest part of the earth's vortex is therefore about fifteen thousand miles this side of the orbit of the moon."
to mean that the outer rim is actually an outer ring 42,000 miles deep, which would make better sense.
If the earth's vortex is 237,780 miles broad, plus a 42,000 miles deep outer ring, the vortex in total would be:
237,780 + 42,000 × 2 = 321,780 miles broad
Now although this is the outer rim of the earth's vortex there can be still a further outer region ring which contains the moon's vortex which is 21,600 miles broad.
237,780 + 42,000 × 2 + 21,600 × 2 = 364,980 miles broad
This figure is still short of the moon's known orbit figure of 477,792 miles broad.

If the swiftest part of the earth's vortex is about fifteen thousand miles this side of the orbit of the moon, the semi diameter is:
238,896 (average distance between the moon and the earth) - 15,000 = 223,896 miles
This makes the swiftest part of the earth's vortex:
223,896 × 2 = 447,792 miles broad.

If the swiftest part is not the outer rim (which is possibly slower due to the moon's inertia), the actual outer edge of the earth's vortex may be still beyond the moon a little, at the interface between Chinvat and the ethe.
If, as Ruth has suggested the "forty-two thousand miles broad" dimension applies to the ring or belt in which the moon travels (considering, in addition, that this size is almost twice [21,600 × 2 = 43,200 miles] the moon's vortex), then maybe this applies to a region outside of the swiftest part of the earth's vortex that lies further out, which might act as a transitional zone that assists in holding the moon's vortex before the relatively stationary region of Etheria.
In that case, the complete diameter up until the bridge of Chinvat would be:
447,792 + 42,000 × 2 = 531,792 miles broad.

If the moon's orbital diameter is 477,792 miles broad then the difference between the outer part of the earth's vortex and the moon's orbit is:
531,792 - 477,792 = 54,000
54,000 /2 = 27,000 miles, which seems further than "just beyond the orbit of the moon".

The following passages from Oahspe (the only ones that relate the position of chinvat with the moon) are all in context of an observer arriving from Etheria.
"And when it entered past Chinvat, and was well within the vortex of the earth in the belt of the moon's orbit, its light spread across the whole atmosphere of heaven"
"the adavaysit, reached Chinvat, the border of the earth's vortex, just beyond the orbit of the moon, and in size twice the moon's diameter."
"the float neared the borders of Chinvat, the earth's vortex, just beyond the orbit of the moon."
"here the boundary of her vortex, Chinvat; just beyond the sweep of the moon"
"when he reached Chinvat, the bridge on the boundary of the earth's vortex beyond the orbit of the moon"

Therefore, one would think that Chinvat was on the earth's side of the moon.

" Now the moon hath, as to the earth's face, no axial revolution. But it must be remembered the moon can not go around the earth without making an actual axial revolution. Seventy and one-half revolutions of the moon's vortex complete one travel around the earth's vortex. Consequently we arrive at the exact speed of the moon's vortexya."

Book of Cosmogony and Prophecy Ch 5:16
The circumference of earth's vortex (Ce) = 70.5 × Circumference of moon's vortex (Cm) [or Ce = 70.5 × Cm]
C (circumference) = π × D (diameter)
Since Ce = π × De (earth's diameter) = 70.5 × Cm = 70.5 × π × Dm (moon's diameter)
This is simplified to De = 70.5 × Dm, or RE = 70.5 × Rm
ie., the ratio of De ÷ Dm is constant (the constant of proportionality being 70.5)

So we use this ratio to find the diameter where the interaction of the two vortices take place, ie., where "the moon's vortex completes one travel around the earth's vortex".

Lets assume that the swiftest part of the earth's vortex is responsible for rotating the moon.
So the diameter there is 447,792 miles broad.
If the swiftest part of the earth's vortex is about fifteen thousand miles this side of the orbit of the moon, the moons vortex at that point is 15,000 × 2 = 30,000 miles broad
447,792 ÷ 30,000 = 14.9 ie., not 70.5
The point where the interaction takes place must be further out.
Juggling the figures a bit, if the point is somewhere say between 447,792 and where the moon's diameter (Dm) = 0
ie., 447,792 + (30,000) = 477,792 miles broad (the moon's orbital diameter)

if we add 23,318 to 447,792 and subtract 23,318 from 30,000 miles
447,792 + 23,318 = 471,110 miles
30,000 - 23,318 = 6,682 miles
471,110 ÷ 6,682 = 70.5

Therefore the hypothesised value of the earth's vortex diameter is 471,110 miles broad.
If the moon's orbital diameter is 477,792 miles broad then the difference between the active part of the earth's vortex upon which the moon's vortex turns, and the moon's orbit is:
477,792 - 471,110 = 6,682
6,682 ÷ 2 = 3,341 miles

Now the swiftest part of the earth's vortex (about fifteen thousand miles this side of the orbit of the moon) is
15,000 - 3,341 = 11,659 miles closer to earth,

If the Moon's diameter = 2,160 miles, this active earth/moon interface is:
3,341 - 2,160 ÷ 2 = 3,341 - 1,080 = 2,261 miles above the moon's surface.
If the Moon's vortex diameter = 21,600 miles, this active earth/moon interface overlaps the moons vortex by:
21,600 ÷ 2 - 3,341 = 10,800 - 3,341 = 7,459 miles, which is small compared to the size of the earth's vortex.

So eight possibilities for the earth's vortex diameter are:
  Miles broad RE (m) Edition Comment
A 478,738 60.46 1882 Moon's distance ~ 60 RE. Closed field line portion of magnetotail ~ 60 RE.
B 475,560 60.06 1891 Magnetosphere ~11 RE on Sun side. Substorm related cross-tail current disruption in magnetotail <15 RE
C 237,780 30.03 1882 Magnetic reconnection occurs ~ 21 RE. Magnetopause flanks ~15 RE abreast, magnetotail 20-30 RE
D 42,000 5.3 1882 Plasmapause 4-6 RE. Van Allen Belt (3 - 9 RE. Ring current 3-6 RE
E 321,780 40.64 1882 Conjecture based on 1882 Edition. Plasmoids originate 20-30 RE
F 447,792 56.55 Both Both, but the 1882 Edition earth/vortex diameter ratio (30 times) contradicts it.
G 531,792 67.16 Both Conjecture based on both Editions.
H 471,110 59.5 1882 Hypothesised value based on 1882 Edition. Magnetosphere became 59.4 RE when solar wind stopped

"As the moon's vortex rides around on the outer part of the earth's vortex, we discover the elliptic course thereof; so by the roads of a comet do we discover the spirality and curve of the master's vortex."

Book of Cosmogony and Prophecy Ch 6:3
So, the earth's vortex holds the moon similar to how the suns vortex holds in comets, and the moon's vortex rides around on the outer part of the earth's vortex.

A), B),F), G) and H) would imply that the earth's vortex is the cause of the moon being held in its place.
The moon's vortex would be at a distance to roll around the earth's vortex, like a grape rolling around an orange (but overlapping). The moon's vortex would rotate with the earth's outer vortex each month, but the moon would not (it's vortex being open).

moon's vortex distance


"In the early age of the vortex of the earth, so swiftly flew the outer rim that border eddies ensued, from which nebula congregated, until the earth had a nebulous belt around it. This belt, in time, losing pace with the earth's vortex, condensed and made the moon."

Book of Cosmogony and Prophecy Ch 4:14
Localised areas of turbulence give rise to vortices. If you look at a log on a river you might see eddies (tiny vortices) formed at its edge. The log is like the earth's vortex, the river like the ether. These "border eddies" are outside of the earth's vortex, but if it the log was the denser fluid of the vortex, they might press into it somewhat and roll around its ellipse, and bob up and down with its undulations.

1) Chinvat seems to be on the earth's side of the moon.
2) Cosmognony Ch 6, 3 tells us the moon's vortex rides around on the outer part of the earth's vortex.
3) Cosmognony Ch 4:14 states that border eddies ensued from the outer rim of the earth's vortex forming a nebulous belt around it that lost pace with the earth's vortex in time, condensed and made the moon. Therefore the moon is beyond the outside of the earth's vortex.

The moon has a revolution with the earth once a month. It is a result of a nebulous belt around the outer rim that lost pace and condensed. The outer rim also has a revolution axially with the earth once a month [1882 Edition], so this must be the active earth/moon interface, hypothesised to be 3,341 miles closer to earth from the moon's orbital diameter, and 2,261 miles above the moon's surface.
The hypothesised outer rim overlaps the moons vortex by 7,459 miles.
If the swiftest part of the earth's vortex, which is hypothesised to be 11,659 miles closer to earth than what I believe to be the outer rim, then the swiftest part must have a revolution with the earth shorter than once a month.

One orbit of the moon (one month) 27.321 days × 23.934 hrs = 653.91 hrs
[One sidereal day is 23.934 hrs
One orbit of the moon takes 27.321 66155 days with respect to the stars [sidereal], having 13.369 passes per year.]

The moon's Orbital circumference (C) = π × D = 3.14159265 × 477,792 = 1,501,027 miles
One orbit of the moon (one month) is 27.321 days × 23.934 hrs = 653.91 hrs
Average velocity (V) at the moon's centre = distance ÷ time = 1,501,027 ÷ 653.91 = 2,295.5 mph
[The period in which the Moon completes an orbit around the Earth and returns to the same position in the sky--the sidereal month--is 27 days, 7 h, 43 min, and 11.6 sec. Because the Earth is moving in its orbit around the Sun in the same direction as the Moon, the time needed to return to the same phase - the synodic month - is longer: 29 days, 12 hours, 44 minutes, and 2.8 seconds.]

Rotational velocity curve for a vortex (galaxy)
rotational velocity curve The hypothesised diameter of the earth's vortex is 471,110 miles broad.
The circumference (C) = π × D = 3.14159265 × 471,110 = 1,480,036 miles
1,480,036 ÷ 653.91 = 2,263 mph
[This is only a rough calculation, and does not take eccentricity (perigee & apogee) into account.]
This implies that it's more than twice as fast [1,038 × 2 = 2,076 mph] as at the surface (1,038 mph), whereas the surface rotates 30 times more [for one rotation of the vortex , as seen by the moon, there are 30 days or one month].
This makes sense for a spiral movement.
The diagram (right) shows the inverse relationship of how velocity increases with distance in a galaxy. If a galaxy is a vortex, the same relationship would exist for the earth's vortex.

Another way of making the same revision would have been to change the wording thus:
The moon's vortex is ten times the moon's diameter, and the earth's ROTATION thirty times ITS PERIPHERAL VORTEX ROTATION.
The moon's vortex is ten times the moon's diameter, and the earth's VORTEX thirty times THE EARTH'S DIAMETER.

Otherwise, we are left with the problem of what holds the moon in its orbit if the edge of both the moon and earth's vortices lie way out of reach.


eddy current

The diagram on the right shows a magnetic field directed into the page (the x inside small circles are symbols of an arrow from the rear). A circular plate moves down through the field, and circular eddy currents are induced in the plate whose direction is given by Lenz's law.
An eddy current is caused by a moving magnetic field intersecting a conductor or vice-versa. The relative motion causes a circulating flow of electrons, or current, within the conductor. These circulating eddies of current create electromagnets with magnetic fields that oppose the change in the external magnetic field (Lenz's law). The stronger the magnetic field, or greater the electrical conductivity of the conductor, the greater the currents developed and the greater the opposing force. This is used in electrical generators and dynamic microphones.
Eddy currents create losses in iron core transformers and alternating current motors. An analogous eddy current is seen in water when dragging an oar.

Many planets have a magnetosphere.
On the sun's side of Earth, the magnetosphere extends out to a distance of approximately 10 Earth-radii [40,000 miles, or 80,000 miles broad] while the magnetotail [see further on] extends several hundred radii in the opposite direction.

Since the measured distance between the moon and the earth is 238,849 miles, that would make the moon six times outside of the magnetosphere's influence.
Though the measurable strength of the earth's dipole field is increased by two times the nominal dipole value [see further on] at the magnetopause (the limit of the magnetosphere) the outer vortex may be of a magnetism or plasma more subtle and undetectable further out [see comment about an open vortex below].

Oahspe sees a planet as a comet. The shape of magnetospheres certainly are like comets

From Oahspe:
"In the case of a vortex in etherea (that is after the manner of a whirlwind on the earth), the corporeal solutions are propelled toward the centre thereof in greater density. When it is sufficiently dense to manifest light, and shadow, it is called a comet, or nebula; when still more dense it is a planet."

"When as a comet (or nebula) the m'vortex hath not attained to an orbit of its own, it is carried in the currents of the master vortex, which currents are elliptic, parabolic and hyperbolic. Hence the so-called eccentric travel of comets.
At this age of the comet, it showeth nearly the configuration of its own vortex; its tail being the m'vortexya. If it appear to the east of the sun its tail turneth eastward; if west of the sun, it turneth westward.
Two directions of power are thus manifested; and also two powers: First, that the vortex of the sun hath power from the east to west, and from the west to east, to which the comet is subjected: Second, that the comet hath a vortex of its own, which is sufficient under the circumstances to maintain the general form of the comet."

"Interior nebula is generally described as comets; whilst exterior nebula is usually called nebula. Nevertheless, all such solutions of corpor are of like nature, being as the beginning or as the incomplete condensation of a planet. They do not all, nor half of them, ripen into planets."

"But nowhere in etherea is there a solution of corpor sufficient to put itself in motion; nor sufficient to condense itself; nor to provide the road of its travel. But its road of travel showeth the direction of the lines of the sun's vortex. As a cyclone, or whirlwind, on the earth, traveleth with the general current of the wind, so travel the sub-vortices in etherea within the axial lines of vortices in chief."

"Of external nebulae, of sufficient size to be self-sustaining, and to ultimately become planets, there are at present visible from the earth more than eight thousand. These are in process of globe-making, even as the earth was made. Of nebulae within the sun's vortex, where they are usually called comets, there are upward of eight or ten new ones every year."

The Electric Universe theory says comets are indistinguishable from asteroids, save that they are moving thru the electric field of the sun in a way that asteroids are not.

To confuse things more, the magnetosphere is shown rotating about the axis along its tail (seen in the link below), which would mean the moon would orbit over the poles if the magnetosphere is the cause of the moon's orbit. But the complex movement of the Magnetosphere is not clear to me yet.
That's not to say there is no vortex, for the same differential rotations are seen about the sun and planets, causing a pattern of cyclones, trade winds, ocean currents, Jupiter's red spot and layers, sunspot rotation and the spiral of the interplanetary magnetic field (IMF).
But what maintains this motion?

There is a gap in knowledge of the cause of earths rotation, magnetic field and electic belts.
One source says:
The intensity of the Earth's magnetic field is about 0.3 Oersted at the equator and 0.6 Oersted at the poles. A typical bar magnetic is about 10,000 Oersted.
The electric currents within the Earth require extremely sensitive instrumentation, how can such small hard to detect currents generate such an awesome magnetic field?
What is causing these Earth's currents? Where is the power coming from?
In all cases, these currents would require power or energy to sustain themselves. Some scientists believe the power is coming from the kinetic energy stored in the rotational mass of the Earth. If this is true, then how much kinetic energy is required to support a magnetic moment as large as the Earth?
Based on a study by G. D. Gibson and P. H. Roberts at University of Newcastle upon Tyne; assuming a radius of the size of the Earth, the magnetic permeability of the Earth's materials and electrical conductivity of those materials the decay time of a conducting sphere is about fifteen thousand years (15,000).
We now can conclude that the Earth's currents, like the magnetic field, require a force to sustain them. This force must be much grander in scale than the Earth's rotational momentum.
The Dynamo Theory is based on motion. The rotation of the body generates the necessary forces to create the generation of a magnetic field.
Now, if this were true, then Mercury which rotates very slowly compared to the Earth and Mars, should have little or no magnetic field. Mars which rotates at close to the speed of Earth should have close to the same magnetic field as Earth. This is not the case. Mars has a very small magnetic field and Mercury has a strong magnetic field.
Within the plasma sheet are currents of electrical particles flowing perpendicular to the plane of the Sun and Earth. There are two currents, one in the northern sector and one in the southern sector of the plasma sheet. Between the two currents is a neutral sheet where current flows together. The potentials of 1 to 8 thousand volts are commonly present.
Areas as the Van Allen radiation belts potentials can be as high as 100 million volts. Because these are high currents and are of astronomical size in a high resistance environment P = I2 × R, the energy required to support the currents is astronomical. The energy is of the proportions such that if applied to stop the Earth, it could bring the Earth to a stand still within one revolution about the Sun.

This link has many diagrams of the magnetosphere.

Many are movies, and can seen by downloading and running Quicktime (there should be no cost).

Try this link for Quicktime


A magnetosphere is that region in which the motion of charged particles are dominated by a planet's magnetic field.

Purple magnetosphere mercury

The Earth's Magnetosphere (above)

Mercury's Magnetosphere (right)

saturn's magnetosphere neptune's magnetosphere

Neptune's Magnetosphere (above)

Saturn's Magnetosphere (left)

What a magnetosphere looks like is partly given to us by computer simulations. If the model is wrong, the shape is wrong. Even observational data relies on correct interpretation and reference frame. For example, the Earth's magnetism does not extend as far into space as would be predicted from the Earth's internal field alone. Plasma acts as a kind of electromagnet. The magnetosphere's shape is the sum of magnetic fields from currents that circulate in the magnetospheric plasma, which are not caused by the geomagnetic field, but something external.


When the solar wind reaches a magnetized planet such as Earth, this collisionless plasma interacts with the magnetic field, initiating a process that enables the solar wind to influence the upper reaches of the atmosphere. The magnetosphere behaves like a compressible fluid. It is made to flap and compress by the solar wind. The flapping and compression form electromagnetic storms.
The interaction between the solar wind, the magnetosphere, and the atmosphere produces a number of plasma and magnetic field structures, including the magnetopause, magnetosheath, boundary layers, cusp region, plasmasphere, ring current, plasma sheet, magnetotail, and magnetotail lobes. Each of these regions maps along magnetic field lines into the atmosphere-ionosphere system and is the origin of energetic inputs that perturb the state of the plasmas and neutral gases.
The transport of mass, momentum, and energy into and through magnetospheres and ionospheres is a fundamental yet poorly understood process.
A global perspective requires that the local small-scale plasma processes be placed in the context of the large-scale system, and ideally, provides a connection between small-scale processes occurring simultaneously in widely separated parts of the magnetosphere-ionosphere system.

Diagram of the Earth's magnetosphere, showing the flow of the solar wind through the bow shock (where its flow goes from supersonic to subsonic) and around the current sheet known as the magnetopause, which forms the boundary between the magnetosphere and the solar wind. Through interconnection of magnetic fields and through entry of particles across the magnetopause, solar wind mass, momentum, and energy are transferred to the magnetosphere. Some of this energy ultimately finds its way into the Earth's atmosphere.

In situ measurements of the vast astrophysical plasma systems like the Crab nebula, clearly laced with magnetic fields, hot gasses, and highly energized charged particles, are not possible. But many measurements have been made of the constituent gases, fields, and plasmas within the Earth's and other planets' magnetospheres.
Many links in the transfer of energy, mass, and momentum from the solar wind and have been identified. Space physicists now know that transport of solar wind energy and momentum takes place across narrow boundary layers that separate regions with very different plasma conditions. The importance of these boundary layers in transport processes and particle acceleration in several regions of the magnetosphere, such as the plasma sheet, has also been identified. The polar atmosphere functions as the sink for a significant fraction of the energy transferred from the solar wind to the magnetosphere.

The Earth's Magnetosphere

The Earth has the strongest magnetosphere of all the rocky planets. The Earth's north and south magnetic poles reverse at irregular intervals of hundreds of thousands of years.
The Earth's magnetic field has a strength of about 6E-5 tesla at the poles. Above the surface, this field resembles a dipole reaching 36,000 miles (about 9 RE) into space. On the sun's side of Earth, the magnetosphere generally extends out to a distance of approximately 10 Earth-radii [40,000 miles] (RE=6400 km) while the magnetotail extends several hundred radii in the opposite direction.
The geomagnetic field can be approximated by a dipole field with an axis tilted about 11 degrees from the spin axis.

The outer boundary of the magnetosphere is called the magnetopause. It is a thin plasma layer that separates the solar wind magnetic field from the Earth's magnetic field. At this location the plasma pressure of the solar wind is in equilibrium with the magnetic pressure inside the magnetosphere. Due to a continuous variation of the solar wind pressure, this boundary moves continuously. It is characterized by a number of transient phenomena and by two major boundary layers, one at low latitudes and one near the poles. Both of the boundary layers are important sources of plasma for the magnetosphere, but the mechanisms forming the boundary layers themselves are still not fully understood.
The magnetopause is considered an impenetrable boundary, but some plasma from the solar wind can enter the magnetosphere. Various processes proposed to account for this penetration of plasma include pressure pulses (when the solar wind pressure suddenly increases, leading to an indentation of the magnetopause), and reconnection between the interplanetary magnetic field and the Earth's magnetic field.

bow shock

Bow shock around a young star located in the intense star-forming region of the Great Nebula in Orion. A star emits a stellar wind outward from the star which collides with slow-moving gas evaporating away from the center of the Orion Nebula. The surface where the two winds collide is the crescent-shaped bow shock.
In front of the dayside magnetopause is the bow shock. Here the solar wind is decelerated from supersonic to subsonic speed before being deflected around the Earth. The region between the bow shock and the magnetopause is called the magnetosheath. The magnetosheath plasma forms an important part of the low energy dayside auroral precipitation . This is because the plasma has an entry to the ionosphere via the dayside cusps and the magnetospheric boundary layer .
The mapping of the boundary layer regions to low altitude is not certain, although it is clear that these spatially vast regions map into a very limited region around the low altitude cusps.
At low-altitude, magnetosphere ends at the ionosphere. The magnetosphere is filled with plasma that originates both from the ionosphere and the solar wind.
The magnetic field lines of the Earth can be divided into two parts according to their location on the sunward or tailward side of the planet. Between these two parts on both hemispheres are funnel-shaped areas with near zero magnetic field magnitude called the polar cusps. They provide a direct entry for the magnetosheath plasma into the magnetosphere.

magnetospher inner magnetosphere

Magnetosheath plasma enters low-altitude cusp which maps onto the dayside of the auroral oval.
The Earth's magnetic field at the magnetopause is mostly tangential to the magnetopause, making a barrier to solar wind particles. The magnetic field is approximately perpendicular to the magnetopause at the cusps, allowing a more direct entry of solar wind particles into the geomagnetic field, southward of the cusp in the entry layer and northward of it on the magnetic lobes. The high-altitude (exterior) cusp (right) can be considered to be a part of the magnetospheric boundary layer system (left).
Inner magnetosphere with high and low-altitude cusps marked.
It is connected to the low altitude cusp. The low-altitude cusp is the dayside region (above, right) in which the entry of magnetosheath plasma to low altitudes is most direct. The exterior cusp is a very turbulent region with vortices in the plasma flow. The magnetosheath plasma penetrating into the low-altitude cusp (and the surrounding low-altitude boundary layer regions) is responsible for part of the dayside auroral precipitation. In addition to plasma, many types of waves and turbulent flows also have access to the ionosphere via the cusp. These include solar wind and magnetopause variations.

The magnetosphere contains various large-scale regions, which vary in terms of the composition, energies, and densities of the plasmas that occupy them. The sources of the plasmas that populate these regions are the solar wind and the Earth's ionosphere; the relative contributions of these two sources to the magnetospheric plasma vary according to the level of geomagnetic activity.
The magnetosphere is a dynamic structure that responds dramatically to the dynamic pressure of the solar wind and the orientation of the interplanetary magnetic field (IMF). Its ultimate source of energy is the interaction with the solar wind. Some of the energy extracted from this interaction goes directly into driving various magnetospheric processes, while some is stored in the magnetotail, to be released later in substorms. The principal means by which energy is transferred from the solar wind to the magnetosphere is a process known as "reconnection," which occurs when the IMF is oriented antiparallel to the orientation of the Earth's field lines. This orientation allows interplanetary and geomagnetic field lines to merge, resulting in the transfer of energy, mass, and momentum from the solar wind to the magnetosphere. The viscous interaction of the solar wind and the magnetosphere also plays a role in solar wind/magnetosphere coupling, but is of secondary importance compared with reconnection.

Reconnection is thought to be the main link in the solar wind - magnetosphere coupling process, occurring at the dayside magnetopause between southward directed IMF and the northward directed geomagnetic field. It is the main process that transports mass, momentum, and energy from the solar wind into the magnetosphere, and it drives the large scale magnetospheric convection. There are several reasons to believe the existence of such a process:

there is a clear correlation between the IMF BZ direction and geomagnetic activity some measurements indicate the presence of unexplained processes at the magnetopause some theories can explain the formation of such processes (e.g., the tearing mode instability) There are two basic types of reconnection models:

quasi-static reconnection (QSR) flux transfer event (FTE) In addition to the dayside reconnection, similar process should be occurring in the far tail. Finally, some substorm models are also based on reconnection. This is quite natural, since the magnetic field field lines above and below the cross-tail current sheet are oppositely directed, and the plasma sheet is typically thinning during the substorm growth phase.

There is no question about the source of ionospheric plasma, since it is created from the ambient neutral atmosphere by ionization. However, the source of magnetospheric plasma is a much more complicated question: although it seems obvious that both solar wind and ionosphere feed it, the relative importance of these two sources is unclear. Furthermore, it seems also that plasmasphere can provide part of the plasma in plasma sheet; although it originates, in the end, from ionosphere, the transport mechanism is quite different than in direct ionospheric outflow.

When studying the plasma source, separating different ions is important. Protons (H+) are the primary ions in solar wind and one of the major components in ionospheric outflows, and thus not good indicators of their source. Also He+ has a mixed origin (Kremser et al., 1993). However, O+ (and O++) come from ionosphere, and He++ and highly charged oxygen from solar wind (Kremser et al., 1987). The original idea that magnetospheric plasma would invariably be of solar wind origin was first seriously questioned when precipitating O+ was discovered in early 1970s. First observations of direct ion outflows were made few years later, and ionospheric ions were observed in the magnetosphere by GEOS-1 satellite (Geiss et al., 1978). Today we know that O+ can be found from ring current, inner plasma sheet, and far magnetotail. Especially high geomagnetic activity enhances ionospheric plasma presence in the magnetosphere. On the other hand, quiet time plasma sheet plasma seems to be at least partly controlled by solar wind (see, e.g., Winglee, 1998).

The effect of the geomagnetic activity is obvious in long time scales, and magnetospheric O+ content displays clear solar cycle variation. In addition, it has been suggested that ionosphere response could be fast enough to control the evolution of dynamic geospace processes like substorms via transient and localized dominance (Daglis and Axford, 1996). See also magnetosphere - ionosphere coupling.

Although the (partial) ionospheric source is well established, there are no reliable quantitative estimates of the outflow and its spatial extent, and the speed of the transport is not known. Finally one should be able to show what mechanisms are doing the energization from cold ionospheric source plasma to relatively high energy plasma sheet plasma.

Polar Caps, polar wind and Polar rain

The magnetosphere can be divided into two large regions, one containing closed field lines and the other containing open field lines. Each of the regions has its ionospheric mapping. The ionospheric footprints of the open-field-line regions are called polar caps. The closed-line region extends to relatively low magnetic latitudes, starting from ~ ±75° equatorward, whereas the open-line region maps to the latitudes approximately above ~ ±75°. The latitude of this open-closed field line boundary is not constant and can change dramatically during the magnetosphere dynamic evolutions.

Polar caps form one of the ionospheric sources of magnetospheric plasma. This is due to the so-called polar wind (1968). The proposed mechanism for this "classical" polar wind, ambipolar electric field, separates it from other ion outflow events. The classical polar wind characteristics are that it is cold, field-aligned (out of the ionosphere), and the velocities are inversely correlated with ion mass, favouring lighter ions (H+ and He+). Later observations revealed day-night asymmetries in the ion and electron features, and O+ outflows (1993). Furthermore, the outflow velocities increase with altitude and are supersonic at high altitudes.

Polar rain is spatially homogenous few hundred eV electron precipitation into the polar cap. The open polar cap field lines are connected to the lobes (left) of the magnetic tail, and polar rain electrons have been observed also there. The origin of the polar rain electrons is the solar corona, i.e., they belong to the suprathermal (halo) portion of solar wind electrons (1985). In polar rain, there is typically little or no ion accompaniment.
Polar rain can be used as a diagnostic tool for open field lines (1998). However, although field lines with polar rain are certainly open, field lines without it are not necessarily closed. Polar rain shows a strong hemispherical asymmetry, with the northern hemisphere favoured for an away IMF sector structure (1976) and the southern hemisphere favoured for a toward IMF sector structure. Also a dawn-dusk gradient controlled by IMF By has been observed (1977). As the dayside merging affects the size of the polar cap, also the IMF BZ component affects the polar rain (1984).

The magnetotail

The magnetotail is the main source of the polar aurora. It was once widely believed that auroral electrons came from the Sun. But the brightest auroras were seen around midnight. Those observations made much more sense after satellites discovered and mapped the magnetosphere's long tail.

Comparison of Typical Plasma Densities
Solar wind near Earth 6 ions/cubic centimeter
Dayside outer magnetosphere 1 ion/cubic cm
Plasma sheet separating tail lobes 0.3 -- 0.5 ions/cubic cm
Tail lobes 0.01 ion/cubic cm

Most of the volume of the tail is taken up by two large bundles of nearly parallel magnetic field. The bundle north of the equator points earthwards and leads to a roughly circular region including the northern magnetic pole, while the southern bundle points away from Earth and is linked to the southern polar region. These "tail lobes" extend far from Earth. Satellites found them well-defined even at 200-220 RE (870,980 mls) from Earth.
At those distances the lobes are already penetrated by some solar wind plasma, but near Earth they are almost empty.
This low density suggests that field lines of the lobes ultimately connect to the solar wind, somewhere far downstream from Earth. Ions and electrons then can easily flow away along lobe field lines, until they are swept up by the solar wind; but few solar wind ions can head upstream, so little plasma remains in the lobes. The plasma sheet separates the two tail lobes. It is a layer of weaker magnetic field and denser plasma, centered on the equator and typically 2-6 RE thick. Unlike field lines of the tail lobes, those of the plasma sheet cross the equator (ie., are closed field lines), though they are stretched out. A weak magnetic field means that the plasma is less restrained here than nearer to Earth, and on occasion it flaps around.
The closed field line portion of the magnetotail is usually less than about 60 RE (237,540 ml).
The swiftest part of the earth's vortex (the edge of the vortex) is 223,896 mls.
The plasmasphere and plasma sheet are closed-line regions while tail lobes and mantle are open-line regions. The boundary plasma sheet (BPS) and low latitude boundary layer (LLBL) are transition regions because they contain the field lines of both types. The mantle contains the most recently reconnected field lines that are dragged tailward by the solar wind. The region of dayside reconnection (and its ionospheric projection) is called the cusp. It projects to a short strip at ±(76°–77°) of magnetic latitude.
The equatorial projection of the plasmapause (i.e. its outer boundary) is typically found near 3-6 RE. The inner plasmasphere is a region inside of the plasmasphere that corotates with the earth. Electron density in the plasmasphere is of the order of ~ 100 cm-3 and falls off by 2-3 orders of magnitude across the plasmapause. The plasmasphere contains the major part of the trapped and bouncing charged particles forming the Van Allen radiation belts.
The plasma sheet extends tailward for several tens of RE in the form of a slab. The plasma sheet contains the so-called cross-tail current sheet. Electron density in the plasma sheet is ~ 0.1 - 1 cm-3. It contains hot particles with the energies up to tens of keV. The ionospheric projection of the plasma sheet is observed at ~ 65° – 75° of geomagnetic latitude.
The boundary plasma sheet, BPS, is the region between the plasma sheet and mantle. In the BPS the tail reconnection occurs, so the open field lines of the outer BPS become closed and move toward the plasma sheet. Sharp ion streams are characteristic of the BPS, average energy being a few keV. The BPS ionospheric projection is observed at ~ 67° – 77° of geomagnetic latitude.
The northern tail lobe and the southern tail lobe are the regions adjacent to the plasma sheet, containing open field lines in the earthward and tailward directions, respectively. Plasma densities are low (< 0.01 cm-3) in this region, and the ion and electron energy spectra are very soft, typically ~ 20 eV.
The mantle is a boundary layer several thousand kilometers thick just inside the magnetopause. It contains particles of low densities, less than 0.1 cm-3, with energies up to hundreds of eV. Its ionospheric projection on the dayside is between 77° and 81°. The mantle is a region of newly-reconnected open flux lines. Its lines of force are dragged tailward by the solar wind flux lines.

diffuse aurora The low-latitude boundary layer, LLBL, is a relatively thin (0.5 – 1 RE) boundary layer located earthward of the magnetopause. Its ionospheric projection is a thin semicircle called the cleft, observed at about 77° between ~ 10 and 14 MLT (Magnetic Local Time). Its characteristic electron densities are ~ 0.5 - 10 cm–3 with the energies from less than 100 eV to 1000-2000 eV. The LLBL is a current generator region because it maintains the process of charge separation inside of itself.

Because of the weak field in the plasma sheet, the ions and electrons of the plasma sheet are constantly stirred up, and some of them leak out of the ends of their magnetic field lines. As such electrons approach the Earth, most bounce back due to the action of converging field lines, but some reach the atmosphere and are lost, producing the diffuse aurora (right). The eye cannot see this spread-out glow, but satellite cameras do, showing a "ring of fire" surrounding the Earth's polar caps at most time.
The diffuse aurora expands and contracts as the tail lobes swell and shrink due to variations in the solar wind and its magnetic field.

Plasma Convection

If tail plasma continually leaks out of the plasma sheet, new ions and electrons must arrive to take its place, or else the plasma sheet would soon be drained and the extended tail field would quickly collapse.
There are two possible solar wind energy transfer mechanisms for convection in the magnetosphere: viscous interaction, and reconnection.

viscous interaction

Two models of the solar wind/terrestrial magnetic field interaction. Left: viscous processes, Right: magnetic reconnection
In the viscous interaction theory [1961] it is assumed that the solar wind transfers momentum and energy into the magnetosphere in a process similar to that within a falling raindrop, in which the fluid is swept back at the surface and returned inside the drop (left). The problem with this theory is that the solar wind is too tenuous to cause a sufficient collisional force (the mean free path is ~109 km and collisions are virtually absent).

neutral point The other theory proposed by James Dungey [1961] suggested an answer to how fresh plasma is supplied. In an ideal plasma, ions and electrons that share a field line move together and continue sharing it at all times ("like beads on a wire"). Dungey pointed out an exception to this rule, that when the plasma flowed through a neutral point or "neutral line" at which the magnetic force was zero, the plasmas on both sides of that point could become separated and could "reconnect" to different field lines. Dungey suggested that such a neutral point existed near the front of the magnetopause (marked N on the diagram). He proposed that interplanetary field lines (with the plasma riding on them) linked up there with terrestrial ones, forming compound lines (“open flux tubes”), like the one to the right of "3". That line contains a sharp bend. Most of the plasma on the section beyond the bend is interplanetary, most of it on the section closer to Earth is terrestrial. However, both plasmas move together, continue to share the same line, and slowly intermix.
The open tubes are then carried downstream by the magnetosheath flow and stretched into a long cylindrical tail (line "3" moves to the line "4" position, then to the position "5", and perhaps half an hour after that the open tubes close again by reconnection in the centre of the tail, somewhere downstream of Earth, at a neutral point or line near the number "6", presumably in the boundary plasma sheet (BPS) region.The interplanetary parts (the open field lines) are then rejoined back to regular IMF lines in the solar wind and flow away, and the terrestrial halves are reunited and become closed field lines, which return through the plasma sheet. These field lines shrink as they move sunward along the magnetosphere flanks and eventually get into the dayside part of the magnetosphere, where they become subject to the dayside reconnection again.
Neglecting spill-over at boundary points like the sharp bend in line "3" (and glossing over some important, and as yet not completely understood, plasma physics), one realizes that this process will transport near-noon plasma to the distant tail, then back earthward, creating a circulation of plasma in the magnetosphere and bringing fresh ions and electrons into the plasma sheet, from the vicinity of "6". The process is often named "convection", and the overall flow cycle is ~ 12 hours, of which field lines remain open mapping into the tail lobe for ~ 4 hours and then take ~ 8 hours to convect back from the tail to the dayside.

Under the solar wind conditions favourable for the reconnection, the ionospheric image of the magnetospheric flow consists of two convection cells with antisunward flow of open field lines over the polar cap and a return sunward flow of closed field lines at lower latitudes.
This convective flow is associated with a large-scale electric field in the plasma directed from dawn to dusk. The voltage between the foci of the cells is of order 100 kV and is associated with the ionospheric flows of several hundreds m/s. Generally, the drift velocity v, electric field E, and magnetic field B are associated in the equation    v = (1/B2)  E × B
This equation describes the Hall drift of charged particles in the direction perpendicular to those of the electric and magnetic fields. This process occurs under the condition of stable negative IMF BZ only.

[Note that THEMIS recently observed that 20 times more solar particles get into the magnetosphere when the IMF points northward. Before that it was found that energy from the sun gets into the magnetosphere when the IMF points southward.]

The charged particle populations, travelling with the reconnecting IMF field lines, penetrate into the magnetosphere, carrying the momentum and energy from the solar wind. Hence the term “open magnetosphere” describing its state under negative IMF BZ.
During the periods of positive IMF BZ, the reconnection process at the subsolar region of the magnetopause ceases, and so does the input of particles, energy, and momentum. Therefore this state is referred to as closed magnetosphere. The IMF field lines do not merge with those of magnetopause, but slide down the magnetotail with solar wind. The magnetosphere-ionospheric system also undergoes a number of changes, among which is vanishing of the Region 1 Birkeland field-aligned currents.

Flows of plasma consistent with Dungey's prediction, have been observed by satellites. The electric field associated with them has also been measured, and most scientists now support the notion of circulating plasma. The earthward flow in the tail has been harder to confirm and is irregular, coming in fits and bursts, especially during magnetic substorms.
The reconnection process received support in 1966, after spacecraft began monitoring the IMF. It then became evident that "storminess" of the magnetosphere ("magnetopheric activity") occurred primarily when the north-south component BZ of the IMF pointed south. Also, while magnetic storms required the arrival of a blast of solar plasma, overtaking the solar wind and preceded by a shock front, big storms and severely compressed boundaries usually required a southward BZ as well.
qq "Geotail" observations suggested that the neutral point near "6" occurs about 70-100 RE (277,130-395,900 mls; moon's distance is 254,186 miles at apogee. This would have been about near or beyond the bridge of Chinvat, but THEMIS gives a differnt value).

Near-Earth Neutral line (NENL), Null-Null Line, X-line and Substorm Location

sequence of the auroral pattern
Sequence of the auroral pattern during an auroral substorm viewed above the magnetic pole.
The concentric circles denote latitudes with 10º spacing.
The location where a substorm is initiated is a four-decade-old mystery. Auroras are indicators of a huge electrical current (~ 1 million amperes) associated with a disturbance. Before the onset of substorm activity, auroral displays occur in curtain-like forms aligned nearly in the east–west direction, referred to as auroral arcs (a). The disturbance begins when the auroral arc in the near-midnight or late-evening hours suddenly brightens. When several auroral arcs are present, the one at the lowest latitude typically brightens first (b). The brightened arc then starts to move toward the pole. As a result, the auroral pattern appears to form a bulge (c). A large-scale wavy structure forms at the western end of the bulge in the late evening hours and propagates westward (c and d). This wave structure is associated with a variety of folds and violent auroral motions. In the morning hours, the auroral arcs tend to break up into patches drifting eastward. This furious activity begins to cease when the bulge stops its advance to higher latitudes and the auroral brightness begins to dim (e). The auroral activity gradually subsides, and auroral arcs become the dominant form in the night sky (f).

[The most spectacular form of discrete auroras is the substorm related auroral bulge. The bulge is formed close to the midnight sector, and it is characterized by rapid poleward motion. The poleward expansion of the bulge is not continuous, but stepwise. There are 3 types of discrete aurora within a bulge.
1) a surge [westward termination of the bulge] 2) north-south aligned auroras 3) eastward propagating auroras
The N-S auroral region is thought to be a channel through which plasma sheet plasma is injected into the ring current.]

magnetic reconnection

The magnetic reconnection process. The magnetic field lines are drawn in blue before reconnection and in orange after. The red arrows denote the motion of the charged particles (v) associated with the magnetic field lines. The accompanying electric field component perpendicular to the reconnection plane Ey (pointing out of the image) is also shown.
The origin of the furious activity in auroral substorms has intrigued space scientists since the inception of the substorm description. The conventional wisdom is that substorms are caused by magnetic reconnection. The substorm extracts the stored magnetic field energy to accelerate charged particles by forming a configuration in which the magnetic field are visualized as having its lines of force cut and joined back in a different manner (right).

magnetic reconnection

Reconnecting magnetic field lines
The magnetic field lines at the top and bottom are visualized to be transported toward the X-type configuration. At the X-point, the magnetic field line from the top is presumed to be cut and then joined with the magnetic field line from the bottom. This alteration leads to two different magnetic field lines, one moving to the left and the other to the right. These magnetic field line motions carry along the charged particles associated with them. This process releases magnetic energy stored in the top and bottom parts of the field configuration to the charged particles moving to the left and right. Substorm theory based on this idea invokes this process occurring in the magnetotail about 20 RE downstream. This model is referred to here as the mid-tail initiation model.

Turbulence in the current disruption region

Turbulence in the current disruption region where the electric current is broken up into filaments with various intensities and with some reversing in direction as well. The associated electric field is also highly variable in strength and direction. Plasma is accelerated to high speeds by forces resulting from the current disruption process.
The other competing substorm model envisions turbulence from a plasma instability to be the main physical process responsible for the onset of substorms.
[A Plasma instability is a region where turbulence occurs due to changes in the characteristics (temperature, density, electric fields, magneti fields) of a plasma. Some plasma instabilities include z-pinch, cyclotron, diocotron, whistler cyclotron, filamentation, helical and magnetic drift instability.]
The plasma instability is triggered by the high electrical current density in that region just before the onset of activity. The magnetosphere cannot sustain such a high current density and leads to a sudden disruption of the current. This situation is similar to current disruption in an electrical circuit. The observed plasma turbulence in this region is due to the nonlinear evolution of the instability. Since magnetic field energy is associated with a current system, current disruption essentially releases that energy to the charged particles. The energy release may involve an X-type magnetic field configuration envisioned in magnetic reconnection but is not necessarily present in all current disruption events. The current disruption location is found to be near the transition region at about 10 RE downstream, where the magnetic field resembling the Earth’s dipole field configuration changes to the stretched magnetic field found in the magnetotail, as depicted above. This model is referred to here as the near-Earth initiation model.

near-Earth initiation model

Substorm model comparison. Time sequence is indicated by steps 1-4. In the near-Earth initiation model (top), the current intensity (J) is indicated by the size of the circle. A plasma process causes current disruption (CD) on the magnetic field line connected to an auroral arc, which in turn generates a disturbance wave propagating tailward. A new current system, called the substorm current wedge, is developed by CD. Magnetic reconnection may subsequently develop in one of the CD sites. In the mid-tail initiation model (bottom), magnetic reconnection occurs in the mid-tail, causing an Earthward plasma jet, which in turn slows down near the inner magnetotail to create a substorm current wedge (NENL = near-Earth neutral line).
In the near-Earth initiation model, the first sign of substorm onset occurs in the transition region. A plasma process occurring primarily on the equatorial plane is initiated to disrupt the current that flows duskward there, causing it to divert its path to the ionosphere to form a current system called a substorm current wedge. The redirected current due to current disruption is responsible for the dynamic auroral display during substorms. Current disruption accelerates plasma primarily to Earth and launches a disturbance wave that propagates away from Earth. This disturbance wave instigates current disruption at other sites, leading to the presence of multiple current disruption sites. Magnetic reconnection may occur in one of these current disruption sites.

In the mid-tail initiation model, the first sign of substorm onset occurs deep in the magnetotail where magnetic reconnection takes place at a site called the near-Earth neutral line (NENL). It produces a high-speed plasma flow directed to the Earth. This flow slows down as it encounters the strong magnetic field from Earth, and flow braking creates a dawnward current, generating a substorm current wedge as a result. Clear distinctions between these two models are the location where the disturbance first appears and the propagation direction of the disturbance, even though the subsequent extent of the disturbance in each model can encompass both the transition region and the magnetotail.

The NASA THEMIS (Time History of Events and Macroscopic Interactions during Substorms) mission, consisting of five identical satellites, is attempting to resolve this substorm onset mystery. Three inner satellites at ~10–12 RE downstream distances will monitor current disruption onsets, while two outer satellites, one at 20 RE and the other at 30 RE downstream will monitor magnetic reconnection onsets.

While the magnetospheric substorm related cross-tail current disruption and the formation of the SCW take place in the near-Earth tail, <15 Re, the observed high speed plasma flows indicate that important substorm processes occur at about 20-30 Re.
The near-Earth Neutral line (NENL 1996) model assumes that reconnection takes place between the oppositely directed field lines above and below the current sheet at a distance of about 20 - 30 Re (this is considered near-Earth as opposed to the distant tail reconnection). 11 Aug 2008
A 3-D "magnetic snapshot" of the heart of a magnetic reconnection region has been obtained in-situ by Cluster at one-third of the distance to the Moon from Earth (21 RE).

the event triggering substorms in the magnetosphere surrounding the Earth originate deep in the planet's shadow, about a third of the way to the moon. According to the "current disruption" model, the solar wind causes large currents to build up in space. Sudden disruption of these currents by an explosive instability can cause them to short circuit through auroral currents, initiating a substorm. Substorms can dump energetic particles into the Van Allen radiation belts THEMIS unlocked the mystery of substorm initiation on Feb. 2008, when they recorded plasma density and flow, and electric and magnetic field data. The observations confirmed that magnetic reconnection in the Earth's magnetotail triggers the onset of activity in the auroras, putting a shimmer in the colourful curtain of the northern and southern lights. About 1.5 minutes after reconnection, the aurora brightened rapidly and expanded toward the poles, and then, 1.5 minutes after that, electrical currents flowing in near-Earth space were disrupted. Thus, current disruption is the last event of a substorm, not the first.

Magnetospheric current systems

cross-tail current magnetosphere current systems
3-D cutaway view of the magnetosphere showing currents, fields, and plasma regions.
The combination of constant solar wind plasma flow and the earth’s magnetic field creates several current systems in the magnetosphere. These are the magnetopause current (flows on the surface of the magnetosphere cavity), the ring current (carried by trapped plasma), and the tail current (flowing across the plasma sheet from dawn to dusk (left). It's closing occurs in two branches that follow the magnetopause around either tail).
Across the magnetopause the magnetic field undergoes a sharp change, therefore according to Ampere’s law it contains a sheet of electrical current named the magnetopause current sheet, which covers the dayside magnetopause.


Magnetospheric current systems. The small circle stands for the earth ionosphere.
The tail current sheet covers the magnetotail. Also, the cross-tail current sheet divides the magnetotail at the magnetic equatorial plane into two lobes with oppositely directed magnetic field lines. Thus, the magnetotail cross-section reveals two vortex current cells with opposite senses. The westward ring current flows inside the plasma sheet around the earth. Its sense is opposite to that of the magnetopause current. Some magnetospheric currents lead to field-aligned currents (FACs), which close in the earth’s ionosphere through the Birkeland field-aligned currents that have their ionospheric footprints at ~65 - 75° of geomagnetic latitude.

The magnetopause current
The magnetopause current flows along the surface of the magnetopause so that its magnetic effect cancels the geomagnetic field outside the magnetosphere. In the inner magnetosphere, where the magnetic field is almost dipolar, the contribution from the magnetopause current to the total field is small compared to that from the earth’s internal dipole.
A flow of any high conducting fluid leads to emerging a magnetopause in front of a magnet fixed and not moving with it.
magnetopause current The schematic shows a rectangular fragment of cross-section of the magnetosphere in the XZ plane in the GSM coordinate system. The magnetopause is shown as a thick grey vertical line. The subsolar area on the left contains no terrestrial magnetic field, whereas the magnetosphere on the right is filled with the earth’s magnetic field lines. According to Maxwell’s equation:
           ∇× B = µ0 j,     where µ0 is the magnetic permeability constant of free space.
Curl B can be estimated by replacing it with the circulation integral of B along a thin contour confining a segment of the magnetopause cross-section. The contour is shown as a dashed rectangular path (right). Only the magnetic field inside the magnetosphere (on the right) contributes to the B circulation integral, because the horizontal segments of the contour and its subsolar segment have zero B projections.
Hence the B circulation and the curl B reach maximum at the surface of the magnetopause, and by the above equation the surface must contain the current j with the streamlines perpendicular to the B lines of force, as shown by the circles with dots. The magnetopause current has counterclockwise sense of rotation if viewed from above the North Pole. It makes up two “funnels” near the dipole poles. These funnels indicate the positions of the earth’s geomagnetic field cusps.

Formation of the magnetopause current j. The surface of magnetopause separates the interplanetary medium (on the left) and the earth’s magnetic field B (on the right), therefore the magnetopause must contain the sheet current j.
The tail current
Tail currentThe earth’s magnetic field due to the solar wind action is extended far away from the sun (> 220 RE), forming a tube-like tail. The northern half of this tail confines the magnetic lines of force directed towards the earth, and the southern half confines the lines directed outwards.
The stretching-out of the tail lobes amounts to adding a magnetic field to the magnetosphere. A magnetic field requires electric current to produce it, and the cross-tail current can be viewed as the source of the tail lobes.
Due to the properties of magnetic field, such confined configuration only exists if there are surface currents. The latter are called tail currents. They form two solenoids, coalescent with the magnetopause and cusp currents, bounding the northern and southern magnetic flux tubes (right). The schematic facilitates approximate calculations of the tail current sheet density iT (A/m) from the magnetic flux density BT inside of the tail. These quantities are related as BT = µ0 iT.
Note that the tail current in the plasma sheet and BPS regions is 2iT.
Since BT ~ 20 nT,    iT ~ 1.6 10-2 Am-1,    the current density is ~ 3.2 ×10-2 Am-1 in the plasma sheet.
With the reasonable tail length the total tail current is ~ 108 A.
Tail current in antisunward direction as seen from the earth
The ring current
The ring current flows around the earth clockwise from the viewpoint over the North Pole (see ring current diagram above). Its magnetic field is such that it acts to oppose the earth’s magnetic field. The action of the ring current reveals itself during the global magnetic storms that are characterized by sudden increase in the ground-level magnetic field (due to the initial compression of the magnetosphere from increased solar wind pressure) and its subsequent decompression lasting from several hours to days. For a loop current I generating the field variation ΔB under the assumption that the mirror currents are induced in the conductive ground, the ring current and its magnetic effect are approximately related as ΔB ~ Ir. A moderate magnetic storm may cause a depression of ~30 nT at the surface, therefore the ring current intensification should be 106 A at the geocentric distance ~ 4.5 RE.
The ring current consists of the trapped particles drifting at distances of (4-6) RE from the earth’s surface, between the inner edge of the plasma sheet and the outer edge of the trapping zone. In the course of magnetospheric convection, the particles are accelerated earthward from the tail reconnection point. However, as they enter the regions of stronger magnetic field, they are trapped and join the ring current particle population. The total ring current is proportional to the total energy of the particles.

The Ionosphere

ionospheric structure determined by the electron density The ionosphere is the ionised (and uppermost) part of atmosphere, distinguished because it is ionized by solar radiation and energetic particle precipitation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere, spanning the altitude range from ~ 60 up to ~ 500 km. It influences radio propagation to distant places on the Earth and is located in the Thermosphere.
A typical vertical ionospheric structure determined by the electron density is shown right. The ionospheric regions are designated D, E, F1 and F2. The lowest D region 13 spreads from ~ 60-90 km of altitude. The E region occupies the altitudes from ~ 90-160 km. The F region is located from ~ 160-300 km. The F region itself is subdivided into the F1 region, from 160-180 km and the F2 region, above 180 km. The D and F1 regions vanish at night, and the E region weakens, whereas the F2 region persists at reduced density.
This layered structure reflects differences in the ionospheric plasma behaviour due to the ion-neutral and electron-neutral collision rates. In the densest D region, both electrons and ions are predominantly collisionally controlled and their motion is not affected by the earth’s magnetic field. In the rarer plasma of the E region, the motion of electrons is controlled by the geomagnetic field (they are magnetised) since the electron-neutral collision rates are not large. The ions are still collisionally-controlled and their Hall-drift motion is negligible. The relative electron-ion drift in the E region causes the electric currents.
Vertical profiles of electron number density in the mid-latitude ionosphere.
In the F region both electrons and ions are magnetised. Since the E × B drift velocity has the same magnitude and direction for charges of the opposite signs, the plasma convection in the F region is not accompanied with the Hall current (though there is still very small Pedersen current that is often neglected).
The current flow in the earth’s space environment obeys the law of continuity and Ohm’s law. The ionosphere-magnetospheric medium is strongly anisotropic in the sense of freedom of motion for electric charges. The frozen-in equation  ∂B/∂t = ∇× (v × B)  implies that the motion of charged particles along the magnetic lines of force is hampered by collisions only, while their motion across the lines obeys the drift law   v = (1/B2)  E × B  and therefore the horizontal motion is much more restricted. This difference in electrical properties is expressed as a difference in the conductivities along and across the magnetic field lines.
The conductive anisotropy of the ionosphere suggests a natural decomposition of the three-dimensional currents j into one-dimensional currents j|| flowing along the (essentially vertical) geomagnetic field lines and two-dimensional ionospheric sheet currents J flowing across the field lines. The currents along the magnetic field j|| are called field-aligned currents (FACs). This decomposition simplifies the calculations related to the magnetosphere-ionospheric coupling and allows considering 2-D height-integrated conductances instead of 3-D ones.

Birkeland field-aligned currents

The conductivity along the geomagnetic field far exceeds that across the field. This means that even small electric fields applied along the magnetic field should lead to a strong field-aligned currents. K. Birkeland (1908) proposed that besides the horizontal ionospheric currents, vertical currents also flow from space into the high-latitude ionosphere. Later these currents were detected with the use of satellites and they received the name Birkeland field-aligned currents.

1 distributions of FACs

Distribution of Birkeland field-aligned currents during (a) weak and (b) active disturbances.
The FACs are nearly always present at a magnitude of about 10–8 to 10–7 Am-2. Two zones, related to the auroral oval, are evident. The poleward FACs regardless of the current polarity (inward or outward) form “region 1” and the equatorward FACs form “region 2” currents. On the earth’s dayside, region 1 is always dominant while around midnight the regions have approximately equal strength. At midnight the flow occurs in three regions, downward-upward-downward. In terms of electrojets, this reversal region is known as the Harang discontinuity. The magnetic activity index Kp is a good indicator of the FACs intensity, because the current density and the Kp index are linearly related.
The total current in the Birkeland system is 106 to 107 A [1992]. Measurements have shown that the total Birkeland currents into is approximately equal to the total of the currents out of the ionosphere. An increase in disturbance level results in equatorward expansion of the Birkeland FAC zones.
The Birkeland FACs originate in the magnetotail via charge separation. It is known that in any force field, whose lines cross a magnetic field, charged particles undergo drift motion in the direction perpendicular to the force and to the magnetic field. The electric field force is the only one that causes both positive and negative charges to drift in the same direction, normal to the magnetic field (positive charges curve opposite to negative, though both go in the same direction). Any other forces (for example, gravitational, frictional, or inertial) make the charges drift in opposite directions, leading to charge separation and to electric current formation.
In the course of tail reconnection the magnetic potential energy is converted into kinetic energy of the particles moving earthward. The particles moving in the non-uniform earth’s field undergo several kinds of charge-separating drifts due to their inertia, the pressure gradient, the magnetic field gradient and curvature. A combination of these drift charge separators leads to the formation of several current filaments closing via the earth’s ionosphere. The ionospheric footprints of these currents make the pattern of Birkeland FACs.
Birkeland current system The region 2 Birkeland current system (except its midnight part) is directly connected to the ring current. The region 2 is the divergence of the ring current. It is caused by the magnetospheric plasma pressure gradients. The dayside (except at noon) region 1 is mapped up to the LLBL region. According to the viscous interaction model, the LLBL forms a generator supplying the current of opposite polarities on the either side of region 1. To explain the region 1 variations due to the BZ Lundin [1991] suggested that the LLBL becomes thinner as BZ becomes more negative, which leads to region 1 currents intensification. Siscoe [1991] introduced a voltage generator in the HBL (high-latitude boundary layer), which in combination with the LLBL current generator provide region 1 source for a partially closed and open magnetosphere. The nightside region 1 currents, except at midnight, are connected to the plasma sheet region. The midnight Birkeland currents are due to the inner magnetosphere processes associated with the substorm activity..

Field-aligned currents (FACs) and Birkeland currents

substorm current wedge When the cross-tail current (horizontal arrows shown right) is disrupted during a substorm a current system called the substorm current wedge (SCW) is formed (vertical arrows). This current is diverted through a circuit consisting of earthward (downward) field-aligned currents (FACs) on the eastern side of the wedge, a westward auroral electrojet in the ionosphere, and tailward (upward) FACs on the western side of the wedge. The current disruption leading to SCW formation is acting on current sheet that has been enhanced and/or propagated closer to Earth during the preceeding substorm growth phase (1987).
At the onset, the region of disrupted current expands longitudinally and radially, away from Earth. Because the current wedge signatures are both in the downward and upward FAC region, they are both rather localized, although the downward part is usually assumed to be more wide-spread.
The initially narrow SCW closes in the ionosphere via the westward travelling surge (1990). A couple of minutes after the onset, the ionospheric FAC regions are separated by 500-1000 km. During the expansion phase, the center of the downward FAC propagates eastward with the auroral bulge. The current in the upward FAC region is carried by precipitating keV electrons. Because the ions that will be carrying the downward current are slow, the current is initially carried by cold (few eV) ionospheric electrons.

Birkeland current A Birkeland current is a specific magnetic field aligned current in the Earth’s magnetosphere which flows from the magnetotail towards the Earth on the dawn side and in the other direction on the dusk side of the magnetosphere. The term Birkeland currents has been expanded to include magnetic field aligned currents in general space plasmas. These currents are driven by changes in the magnetotail (e.g. during substorms) and when they reach the upper atmosphere, they create the aurora Borealis and Australis. The currents are closed through the auroral electrojet, which flows perpendicular to the local magnetic field in the ionosphere.
Auroral Birkeland currents can carry about 1 million amperes. They can heat up the upper atmosphere which results in increased drag on low-altitude satellites.

diocotron instability

Diocotron instability vortices photographed on a fluorescent screen
Auroral curls
Auroral curls are associated with shear velocities and KH instability.
Birkeland currents created in the laboratory have a cross-section pattern that indicates a hollow beam of electrons in the form of a circle of vortices, a formation called the diocotron instability (similar, but different from the Kelvin-Helmholtz instability), that subsequently leads to filamentation. Such vortices can be seen in aurora as "auroral curls".
A diocotron instability is a plasma instability created by two sheets of charge slipping past each other (like "overlapping currents"). Energy is dissipated in the form of two surface waves propagating in opposite directions, with one flowing over the other. This instability is the plasma analog of the Kelvin-Helmholtz (KH) instability instability in Fluid Mechanics. The arms of galaxies are susceptible to the diocotron instability. In the simulation of galaxy formation, Peratt found that "the column electrons spiral downward in counter-clockwise rotation while the column ions spiral upward in clockwise rotation. A polarization induced charge separation occurs in each arm, which produces a radial electric field across the arm. Because of this field, the arm is susceptible to the diocotron instability. This instability appears as a wave motion in each arm.
The complex self-constricting magnetic field lines and current paths in a Birkeland current that may develop in a plasma
Birkeland currents are also one of a class of plasma phenonena called a z-pinch, so named because the azimuthal magnetic fields produced by the current pinches the current into a filamentary cable. This can also twist, producing a helical pinch that spirals like a twisted or braided rope, and this most closely corresponds to a Birkeland current. Pairs of parallel Birkeland currents can also interact; parallel Birkeland currents moving in the same direction will attract with an electromagnetic force inversely proportional to their distance apart (The electromagnetic force between the individual particles is inversely proportional to the square of the distance, just like the gravitational force); parallel Birkeland currents moving in opposite directions will repel with an electromagnetic force inversely proportional to their distance apart. There is also a short-range circular component to the force between two Birkeland currents that is opposite to the longer-range parallel forces.
Size Current Description
20 × 103 m Venus Flux ropes
Cometary tails
102–105 m 106 A Earth's Aurora
108 m 105–106 A Magnetosphere inverted V events
107–108 m 1011 A Sun's prominences (spicules, coronal streamers)
Interstellar structures: various nebulae
1018 m Galactic center
6 × 1020 m Double radio galaxies: bright lobes

Electrons moving along a Birkeland current may be accelerated by a plasma double layer. If the resulting electrons approach the speed of light they may produce a Bennett pinch, which in a magnetic field will spiral and emit synchrotron radiation that includes radio, optical (ie. light), x-rays, and gamma rays.
Plasma physicists suggest that many structures in the universe exhibiting filamentation are due to Birkeland currents. Peratt (1992) notes that "Regardless of scale, the motion of charged particles produces a self-magnetic field that can act on other collections of charged particles, internally or externally. Plasmas in relative motion are coupled via currents that they drive through each other". See Examples in the table.

Plasma Waves

A variety of plasma waves has been observed in the magnetosphere, many viewed as modifications of electromagnetic waves affected by plasma. Two types of resonance exist in a plasma:
1) due to oscillation of charge density (giving resonance at the "plasma frequency")
2) due to the gyration frequencies of electrons and ions in the magnetic field.
The propagation of such a modified wave depends on the position of its frequency relative to the various resonances, as well as on the angle between its propagation and the magnetic field direction, and also on its polarization. Many wave modes exist, but two are of particular interest:
(a) Whistler modes, first noted as whistling sounds descending in tone, heard in the background on telephone lines and on field telephones in World War I. They were recognized to be radio waves whose (very low) frequency overlapped that of audible sound waves. Owen Storey identified their source in 1953 as lightning. In a typical event, the stroke of lightning occurred in the opposite hemisphere, and the wave, in a form modified by plasma surrounding Earth, is guided along magnetic field lines to the opposite hemisphere (because of the ionosphere, it may be reflected, and bounce back and forth more than once). Because of the modified wave mode, propagation velocity depends on frequency - higher frequency travels faster - spreading out the signal into a descending whistle.
(b) Low frequency radio waves (around 150 kHz) are generates on field lines along which the aurora precipitates, and are known (from their wavelength) as "auroral kilometric radiation" (AKR). Though they are quite intense, they are effectively blocked by the ionosphere and were only discovered from space.

IONOSPHERIC CONDUCTANCE EFFECTS IN OCCURRENCE OF SUBSTORMS, GLOBAL STORMS, AND RADAR AURORAS For the magnetospheric sources maintaining FACs of certain intensity the electric field intensity in the ionosphere depends on conductance. The ionospheric conductance depends on the sun’s radiation that experiences seasonal and solar cycle variations, so many phenomena occurring in the high-latitude ionosphere could be controlled by seasonal and solar cycles. I created the first wark to gain in rotation faster than the earth, one year for every eleven. So that when the wark has made twelve of its own years, the earth shall have completed eleven years. qq The geomagnetic activity is highly variable in time. Two mechanisms were suggested to explain this variation: the axial mechanism and the equinoctial mechanism. The axial mechanism is based on the 7.2° tilt of the solar rotation axis with respect to the ecliptic plane. Due to this tilt the earth reaches the highest northern and southern heliographic latitude on September 6 and March 5, respectively. Near these dates the earth is more in line with the sunspot zones, or with midlatitude coronal holes. The axial mechanism can explain the seasonal modulation of geomagnetic activity, but not its diurnal modulation. The equinoctial mechanism was suggested to explains both seasonal and diurnal modulations of the geomagnetic activity. The equinoctial hypothesis states that the variation of angle ? between the sun-earth line (which is close to the solar wind flow direction) and the earth’s dipole axis is the controlling parameter in the variation of geomagnetic activity. It assumes that the coupling efficiency of the solar wind with the magnetosphere is maximim at the equinoxes, when the ? becomes close to 90º, and it is reduced beyond the equinoxes, when the ? sharpens. The angle ? varies seasonally because of the 23.45° tilt of the earth’s rotation axis with respect to the ecliptic plane, and it varies diurnally due to ~11.5° inclination of the dipole axis to the earth’s rotation axis. Its full range is from ~55° to ~125°; the range of the acute angle between the earth-sun line and the dipole axis, ?, is ~55° to 90°. At the equinoxes, ? varies between ~78.5° and 90°, but at the solstices it varies between ~55° and ~78.5°; therefore, at the equinoxes the resulting diurnal variation is relatively weak compared to that at the solstices. Despite the observational support, the way the equinoctial mechanism works has remained unknown [2000]. Boller and Stolov [1970] suggested a theoretical explanation of the equinoctial effect in terms of the Kelvin-Helmholtz’s instability. They proposed that annual and diurnal variations of the angle of attack of the earth’s dipole to the solar wind cause modulations of the conditions favorable for the development of Kelvin-Helmholtz’s instability at the flanks of the magnetosphere. This proposal could explain both diurnal and semiannual variations of geomagnetic activity. However, Russell and McPherron [1973] mentioned that in situ measurements of the solar wind-magnetosphere interaction indicated that this instability is not responsible for geomagnetic activity. 76 The results of in situ measurements of the solar wind-magnetosphere interaction lead to another approach in explanation of diurnal and seasonal variations of geomagnetic activity. Taking into account that geomagnetic activity at the ground level is caused by substorms and that magnitude of the IMF southward component has been shown to control substorm activity, Russell and McPherron [1973] suggested a model of UT/seasonal variations of geomagnetic activity (further referred as the RM model) based on the assumption that the substorm activity reaches its maximum when the earth magnetic dipole is in line with the most probable southward direction of the IMF. This dipole orientation is most favorable for the merging process and hence for the solar wind energy input to the magnetosphere. The direction of the SW flow in the Parker spiral is assumed to be the most probable direction about which the IMF fluctuates. Therefore the controlling parameter is the angle ? between the Z axis of the GSM coordinate system and the solar equatorial plane [Russell and McPherron, 1973]. This angle varies over a range from about 52° at equinoxes to 900 at solstice. When the angle ? reaches minimum value of 52°, which occurs on April 5 at 2230 UT and on October 8 at 1030 UT, the geomagnetic activity is expected to be at its maximum, because at these times the solar wind magnetic field lying entirely in the sun’s equatorial plane has its maximum projection on the Z axis of the GSM coordinate system. The Russell and McPherron [1973] model predicts both seasonal and diurnal variations of geomagnetic activity and suggests that the spring maximum in activity is associated on average with the IMF directed toward the sun and the fall maximum with IMF directed away from the sun. As the IMF polarity varies with the 22-year magnetic solar cycle, the RM mechanism predicts stronger spring maximum for one 11-year solar cycle and stronger fall maximum for another 11-year solar cycle. The RM mechanism is dependent on both tilt of the sun’s rotation axis and earth’s dipole axis with respect to the ecliptic plane and may be considered as a combination of the axial and the equinoctial mechanisms. Fig. 4.1 shows a) the plot of the ? angle, the controlling parameter in the equinoctial model, and b) the ? angle, the controlling parameter in the RM model as functions of months and UT hours (from Cliver et al. [2000]). It is evident that both models predict the increase in geomagnetic activity near equinoxes for daily averaged data. 77 Figure 4.1. A contour plot in degrees of the seasonal and diurnal variations of the controlling parameters in a) equinoctial model and b) Russell-McPherron model. [from Cliver et al., 2000] The equinoctial model (a) predicts maxima of the geomagnetic activity near the largest ? [McIntosh, 1959]; this occurs at equinoxes. The RM model predicts maxima of the geomagnetic activity near the smallest ? [Russell and McPherron, 1973]. The equinoctial model (a) predicts larger UT variation at solstices, but the RM model (b) predicts larger UT variation at equinoxes. The equinoctial model (a) predicts maxima of geomagnetic activity for monthly averages at 1100 and 2300 UT (when ? is the largest). The RM model predicts maxima of geomagnetic activity for monthly averages also at 1100 and 2300 UT when the ? angle is the smallest. The UT variation predicted by the RM model (Fig. 4.1b) has a phase lag of about 6 hours as compared to prediction by the equinoctial model (Fig. 4.1a). The reasons for this phase lag have been discussed in detail by Russell and McPherron [1973]. The UT variations of both angles depend on seasons. At present there are no dou

spherical flame in zero gravity A flame is an exothermic, self-sustaining, oxidizing chemical reaction producing energy and glowing hot matter, of which a very small portion is plasma. It consists of reacting gases and solids emitting visible and infrared light, the frequency spectrum of which depends on the chemical composition of the burning elements and intermediate reaction products. The color of a flame depends on temperature. For a forest fire, near the ground the fire is white or yellow, above the yellow region, the color changes to orange, which is cooler, then red, which is cooler still. Above the red region, combustion no longer occurs, and the uncombusted carbon particles are visible as black smoke. The distribution of a flame depends on convection, as soot tends to rise to the top of a general flame, as in a candle, making it yellow. In zero gravity, such as in outer space, convection no longer occurs, and the flame becomes spherical, with a tendency to become more blue and more efficient although it will go out if not moved as the CO2 does not disperse. A possible explanation is that the temperature is evenly distributed enough that soot is not formed and complete combustion occurs. Lightning is an example of plasma. Typically, lightning discharges 30,000 amperes, at up to 100 million volts, and emits light, radio waves, x-rays and even gamma rays. Plasma temperatures in lightning can approach ~27,700°C and electron densities may exceed 1024/m³.

Null-Null Line

Diagram of Null-Null Line

Electric Current Disruption

Magnetic field structure within the plasma flow reversal region. The magnetic field lines are shown in purple, the plasma flow vectors are in green, and the current disruption sites are in red.

magnetic reconnection region larger than 2.5 million km

Largest reconnection X-line found in the solar wind between the Sun and the Earth (white line). The plasma jets directions associated with the magnetic reconnection process are symbolised by red arrows embedded in the jets (colour coded in orange).
11 Jan 2006
A magnetic reconnection region larger than 2.5 million km has been found in the solar wind Cluster, Wind and ACE satellites have discovered the largest jets of particles created between the Earth and the Sun by magnetic reconnection. The observations in the solar wind provide evidence that the process is fundamentally large scale and quasi-steady in nature.

Strahl, and the Day the Solar Wind Disappeared

strahl bulge along the magnetic field
Electron velocity distribution function in the solar wind. Note the distinct , a suprathermal population carrying the heat flux together with the halo, the hotter isotropic component which is slightly displaced with respect to the maximum of the core part (indicated in red).
Below: Radial decline (increase) of the number of strahl (halo) electrons with heliocentric distance from the Sun.
Electron velocity distribution Within a Coronal Mass ejection not only the usual bidirectional electron streaming, but an additional unidirectional narrower beam has been observed. The narrow (STRAHL) beam is interpreted as coming directly from the Sun without scattering.
Strahl is a part of the solar wind electron velocity distribution that forms a beam. Electron pitch angle velocity distribution data acquired in the slow solar wind shows three different populations. Beside the thermal CORE (95% of the total density), the data exhibits two distinct non-thermal, relatively tenuous components in the suprathermal energy range (from about 70 eV to greater than 1 keV). These are an approximately isotropic HALO population and a strongly anisotropic STRAHL.
[The pitch angle of a charged particle is the angle between the particle's velocity vector and the local magnetic field].
Electron velocity distribution functions as energy spectra (top) and velocity space contours (bottom) for fast solar wind.
Note the core-halo structure and the strahl of suprathermal electrons in fast solar wind.
STRAHL is usually seen at higher energies, is highly aligned in the direction parallel to the IMF and is largely moving away from the Sun. It comprises less than a few percents of the total number density. Thanks to its attributes, the STRAHL is responsible for the main part of the electron heat flux and it can also provide a possible source of electron kinetic plasma instabilities.
In one model, for strahl speeds large compared to the halo thermal speed, after instability saturation the width of the electron pitch-angle distribution exhibits a maximum as a function of electron energy.
In the hotter portions of the electron distribution that are collisionless, freely moving electrons run away to form a strahl, but how the strahl merges into the collisional thermal electron distribution is at present unquantified.

X ray emissions over the North Pole during the polar rain of electrons on May 11, 1999

Data visualization of the X ray emissions over the North Pole during the polar rain of electrons on May 11, 1999.
From May 10-12, 1999, the solar wind virtually disappeared, dropping to a fraction of its normal density and to half its normal speed (going from over one million MPH to 625,000 MPH). This also changed the shape of Earth's magnetic field and produced an unusual auroral display at the North Pole. Starting late May 10 and continuing early hours of May 12, NASA's ACE and Wind spacecraft observed that the density of the solar wind dropped by more than 98% (number of protons per cubic centimeter dropped from between 5 to 10, down to 0.2). Because of the decrease, energetic electrons from the Sun were able to flow to Earth in narrow beams, known as the strahl. Under normal conditions, electrons from the Sun are diluted, mixed, and redirected in interplanetary space and by the magnetosphere. But satellites detected electrons arriving at Earth with properties similar to those of electrons in the Sun's corona, suggesting that they were a direct sample of particles from the Sun.
Beams from the corona do not get broken up or scattered as they do under normal circumstances, and the temperature of the electrons was similar to their original state on the Sun.
Normally our view of the corona from Earth is like seeing the Sun on an overcast, cloudy day. On May 11, the clouds broke and we could see clearly.

northern auroral regions on May 11 and  November 13

Images in visible light compare the northern auroral regions on May 11 and a more typical day on November 13, 1999
Intense polar rain of electrons over one of the polar caps of Earth was predicted 14 years previously. The polar caps typically do not receive enough energetic electrons to produce visible aurora. But in an intense polar rain event it was theorized the strahl electrons would flow unimpeded along the Sun's magnetic field lines to Earth and precipitate directly into the polar caps, inside the normal auroral oval. This was observed in May when a steady glow over the North Pole was detected in X-ray images.
Earth's magnetosphere swelled to five to six times its normal size. Satellites observed the most distant bow shock ever recorded. Normally the magnetosphere extends to 40,000 miles (10.1 RE) on the sun side. On May 11 it ballooned outward almost 235000 miles (59.4 RE), which is about the same distance to the moon.
Right: Animation -The Day the Solar Wind Disappeared
As the solar wind dissipates on May 11, 1999, the magnetosphere and bow shock around Earth expand to five times their normal size. The aurora, which usually forms ovals around Earth's poles, fills in over the northern polar cap.
The density of helium in the solar wind dropped to less than 0.1% of its normal value, and heavier ions, held back by the Sun's gravity, apparently could not escape from the Sun at all. In the wake of this event, Earth's outer electron radiation belts dissipated and were severely depleted for several months afterward.

When the density dropped the magnetosphere grew to exceptionally large dimensions (100 times its typical volume) as the solar wind decayed. Another feature was the appearance of highly energetic flows of electrons parallel to the direction of the magnetic field in the vicinity of Earth. These so-called ‘strahl’ electrons (red arrows) are continuously emitted by the Sun but their flow is usually disrupted by the solar wind, making their fluxes weak near Earth. One surprise in this event was how brightly the Earth’s northern polar cap emitted X-rays in response to the strong strahl precipitation. Because the flow of strahl electrons was so strong, the event provided a uniquely clear demonstration of ‘magnetic reconnection’ between the Earth’s field and the interplanetary magnetic field (IMF; yellow lines in Fig. 1) — the part of the Sun’s magnetic field that is carried by the solar wind. Reconnection produces ‘open’ magnetic field lines that directly connect the magnetosphere with interplanetary space. Because the IMF was pointing away from the Sun during this event, open field lines in the Northern Hemisphere were connected directly to the Sun, whereas those in the southern polar cap were connected to the outer heliosphere — a region of space around the Sun that stretches well beyond Pluto (Fig. 1a). As a result, strahl electrons from the Sun flooded directly into the northern polar cap, but not into the south. This was an outstanding re-verification of an early prediction of reconnection theory. Because the strahl entered the magnetosphere by flowing along field lines, the strahl in the northern polar cap shows which of Earth’s field lines are open. Satellites flying over the polar caps saw pairs of field-aligned currents that, at first sight, appeared to be the normal response to magnetospheric reconnection with the IMF. However, we would expect these to be on closed field lines and, although this was true for the currents near dawn in both hemispheres, near dusk in the Northern Hemisphere they were on open field lines. This can be explained by an extreme rotation of the low-altitude signatures of the reconnection site XS (see Fig. 1a) from noon to dusk. This is consistent with the solarwind proton precipitation seen at dusk. Small shifts of this ‘cusp’ in local time had been predicted, but the magnitude of the shift in this case was a surprise, and may have arisen because the magnetic field in the outer regions of the enlarged magnetosphere was weak. The field-aligned currents at dusk were found to be strong in the Northern Hemisphere, but entirely absent from the south. It seems that this asymmetry cannot be due to the lack of sunlight in the winter (southern) polar cap because the dawn currents were not similarly suppressed. The IMF orientation observed, with components away from the Sun and northward, favours the Northern Hemisphere for a second type of reconnection at a higher-latitude site such as XLN in Fig. 1b. There is no signature of this in the southern polar cap, which offers an alternative explanation of the hemispheric asymmetry. The surprise is that both types of reconnection appear to have taken place simultaneously for an extended period. This may have been possible because the reconnection at XS that generates the new open flux was shifted to the dusk flank, whereas the reconnection of already open flux at X LN may have taken place nearer noon. This stored energy drops when the tail expands because of reduced thermal pressure of the solar wind. Only reconnection that generates new open flux (as in Fig. 1a but not in Fig. 1b) increases the stored energy, and during this event the harmful electrons decayed away to very low fluxes and took longer than expected to recover to normal values. q

Two possible ways in which the IMF can interconnect with Earth’s magnetospheric field.
(Above) New open field lines (red lines) are produced at a reconnection site XS and solar wind energy is directly deposited in the inner magnetosphere and upper atmosphere, as well as being stored in the tail of the magnetosphere because open field lines accumulate there.
(Below) Field lines that are already open are reconfigured by reconnection at XLN, in this example in the Northern Hemisphere. In this instance, solar-wind energy is not added to the tail because no new open flux is produced. The solar wind behind the bow shock (dark blue) is denser than the incoming solar wind (medium blue),whereas the magnetosphere (grey) is the least dense of the three regions.

Ruth said: "the narrow beams of electrons called strahl appear to be what Oahspe describes as the sublimation of corporeal needles polarised linearly".
If strahl were the corporeal needles polarised linearly wouldn’t they be observable all the time? These needles go in straight lines, unaffected by the turbulent solar wind. They are more like sunrays. I would think, in absence of turbulence, strahl align with the linearly polarized corporeal needles, as proof of their existence. When Oahspe says ‘corporeal’ I believe these are more in the magnitude of photons. Photons still have mass and pressure to produce an actinic force.
Earth's own magnetosphere is a more effective and efficient accelerator of particles. The solar wind is insufficient for the radiation belts. There are not enough high-energy electrons in the solar wind to explain how many are observed near Earth. The radiation belts change in response to a variety of solar events. High-speed streams of solar wind, coronal mass ejections, and shock waves from the Sun all can compress and excite the magnetosphere. But it is the pressure and energy of these events, not the particles buried in them, that energizes the particles trapped inside the radiation belts. Also note in the reference below, that the narrow beams of electrons called strahl, appear to be what Oahspe describes as the sublimation of corporeal needles polarised linearly. || Starting late on May 10 and continuing through the early hours of May 12, 1999 NASA's ACE and Wind spacecraft each observed that the density of the solar wind dropped by more than 98%. Because of the decrease (of the solar wind), energetic electrons from the Sun were able to flow to Earth in narrow beams, known as the strahl. Under normal conditions, electrons from the Sun are diluted, mixed, and redirected in interplanetary space and by Earth's magnetic field (the magnetosphere). But in May 1999, several satellites detected electrons arriving at Earth with properties similar to those of electrons in the Sun's corona, suggesting that they were a direct sample of particles from the Sun................ But in an intense polar rain event, Scudder and Fairfield theorized, the "strahl" electrons would flow unimpeded along the Sun's magnetic field lines to Earth and precipitate directly into the polar caps, inside the normal auroral oval. Such a polar rain event was observed for the first time in May when Polar detected a steady glow over the North Pole in X-ray images.|| ||The event that caused the compression of the edge of the earth's magnetosphere much closer to the earth was related to a large magnetic cloud that reached the earth following high levels of solar activity in the form of coronal mass ejections and flares. And the effects also lasted weeks. In the wake of this disturbance, the natural gap between the two radiation belts was filled by a new radiation belt, as energized particles were trapped where they wouldn't naturally settle. The new belt lasted for nearly six weeks.||


The plasmasphere

The plasmasphere, or inner magnetosphere is a region consisting of low energy (cool) plasma. It is located above the ionosphere. The outer boundary of the plasmasphere is known as the plasmapause, which is defined by an order of magnitude drop in plasma density. The plasmasphere's particle motion is dominated by the geomagnetic field and hence it is corotating with the Earth. However, recent satellite observations have shown that density irregularities such as plumes or biteouts may form. It has also been shown that the plasmasphere does not always co-rotate with the Earth.

The Structure and Dynamics of Magnetospheres and Their Coupling to Adjacent Regions

The influence of the solar wind on the magnetosphere creates Kelvin-Helmholtz surface waves along the magnetopause and induces magnetic field line resonance.

surface waves


KH-vortices 2

Kelvin-Helmholtz vortices on the dawnside of the magnetosphere boundary layer (left).
Kelvin-Helmholtz vortices originate where two adjacent flows travel with different speed. In this case, one of the flows is the heated gas inside the boundary layer of the magnetosphere, the other the solar wind just outside it.

Kelvin-Helmholtz instabilities with KH vortices at the duskside magnetopause (right).

Possible plasma entry mechanisms into the magnetosphere include diffusion and magnetic reconnection.
The steady merging of solar wind and magnetospheric magnetic fields, once thought to be the predominant entry process, does not seem to be sufficient to account for all of the features suggested by data. The simple picture of steady-state merging has been replaced by one of transient, patchy, and small-scale merging with associated current systems that map to the polar cap and churn up the ionosphere.
The evidence for reconnection at the magnetopause is very strong, although the microphysics of the reconnection process is still not understood. The interaction of the solar wind with the magnetosphere also sets up a convection system whereby plasma and "frozen-in" magnetic field lines flow from the dayside of the magnetosphere to the tail and then return to the dayside.
While the large-scale flow features have been confirmed by observations in the polar ionosphere, the specifics of the flow patterns throughout the magnetosphere are lacking. As would be expected when the input is transient, the convection is not steady. In fact, recent studies indicate that plasma flow in the magnetotail is usually bursty and irregular.
Two examples of dynamic processes that involve dramatic changes in the entire magnetosphere are magnetic storms and substorms. A magnetic storm is a period of enhanced geomagnetic activity, typically lasting many hours to days. During this period, particles are injected into the outer Van Allen belts to form an intense magnetospheric ring current that depresses the geomagnetic field at low latitudes.
A portion of the ring current connects with the ionosphere, where it produces intense magnetic perturbations. Large magnetic storms can cause significant changes in the inner magnetosphere that are intimately associated with the lowest-latitude occurrences of the aurora. For example, recent observations of the sudden formation of a "belt" of very energetic particles (tens of MeV) show that large magnetic storms can cause major, long-lived changes deep in the inner magnetosphere.
Magnetic storms and substorms cause loss of communication satellites, disruption of radio communications and interruption of electric power to consumers due to power-grid failures. Many aspects of magnetic storms are either poorly understood or not known. These include magnetic storm effects on the geomagnetic tail configuration, the sequential progression of solar wind entry, and the energization of plasma from the ionosphere during storms.
In a substorm, the energy stored in the magnetic field of the tail is released explosively. The most frequently discussed substorm model has been magnetic reconnection in the region between 10 and 30 Earth radii downstream of the Earth. However, recent observations of substorms that are triggered on field lines at distances of 6 to 10 Earth radii seriously challenge this. Moreover, the recent plasma observations at synchronous orbit show very different features from the familiar energetic-particle injections during substorms and are providing new views of the dynamics of energy transport into the inner magnetosphere.
These observations are not fully understood. The types of physical processes that occur in the near-Earth magnetotail region during substorms remain one of the major unresolved issues of magnetospheric physics.
During substorms about 10% of the energy transferred from the solar wind into the magnetosphere is deposited in the auroral ionosphere. A significant fraction is deposited in the ring current and the midlatitude atmosphere, and some is also convected through the magnetopause into the magnetosheath. Studies of the deep tail indicate that the rest of the energy flows down the tail and eventually back into the solar wind.
The coupling process between the magnetosphere and the ionosphere is complex and highly variable. Large-scale current systems, precipitating charged particles, and electric fields are the intermediaries that transport a significant portion of the energy and momentum resulting from the solar wind/magnetosphere interaction into the ionosphere. Precipitating particles from the magnetosphere are the major source of ionization in nightside midlatitude and polar regions. Those particles consist of keV ions and electrons in the auroral zone, lower-energy ions and electrons in the polar cap regions, and relativistic electrons and ions at tens to hundreds of keV at subauroral latitudes.
Currents and electric fields in the magnetosphere also play an important role in the magnetosphere-ionosphere (MI) coupling. The million-ampere magnetospheric currents flow into the ionosphere where they heat the thermal plasma and neutral gas. The ionization level governs the conductivity of the ionosphere and establishes the relationship between current and electric field.
Magnetospheric energy is dissipated in the neutral atmospheric constituents in three ways:
(1) heating due to particle precipitation
(2) heating from the dissipation of currents
(3) energy and momentum transfer to the neutral molecules from collisions with ionospheric ions drifting in electric fields. The resulting changes can lead to feedback effects in the magnetosphere. For example, the large-scale winds of neutral gas that persist even after the magnetospheric driver is turned off can drag ions across magnetic fields and may modify and even create new electric fields and current patterns in the magnetosphere.
Another MI coupling effect comes from the flow of a large number of ionospheric ions up along the magnetic field lines into the magnetosphere. These ions become energized by processes as yet unidentified and could play important roles in MI coupling and magnetic storm and substorm dynamics.
Not much is known about the transport processes in other planetary magnetospheres. The intense auroral emission observed from the jovian polar regions indicates robust MI coupling, but the identity of the precipitating particles (electrons, protons, oxygen or sulfur ions from Io) responsible for those emissions and the energy distribution of the particles have not yet been discovered.
Researchers are even further away from knowing what acceleration mechanisms operate. The dependence of outer planetary aurora on solar wind coupling as opposed to internal dynamics, such as planetary rotation and interaction with satellites, is not yet established.

[ saturnian magnetosphere]

Above: Artist's conception of the saturnian magnetosphere, including major plasma structures and sources and sinks of ions from the solar wind, Saturn, and its rings and satellites
New knowledge about physical processes can also be obtained by studying magnetospheres where one or more of the boundary conditions are different from those at Earth. For example, the role of MI coupling in substorms should be examined at Mercury, which does not have an Earth-like ionosphere.
Outer planets, such as Jupiter or Saturn, provide situations where plasma sources other than the ionosphere and solar wind are important and where energy sources other than the solar wind may dominate.

Geomagnetic Cyclic Variability

Earth is hit by a hot, magnetized, supersonic collisionless plasma (the solar wind) carrying a large amount of kinetic and electrical energy. Some of this energy finds its way into our creating geomagnetic activity which consists of geomagnetic storms, substorms, and auroras. The storms are related to solar wind events, while the substorm activity is more complicated because of the temporal storing of energy in the magnetotail. It is not necessary to have a storm in order to have a substorm. While some auroras (those that extend to low latitudes) are storm-time features and some others (the most active ones) relate to substorms, the oval does not disappear even during the more quiet magnetospheric periods.
Solar wind speed correlates well with geomagnetic activity at time scales longer than about one month. Also the IMF affects the geomagnetic activity, although the energy density of the magnetic field is small in comparison with that of the solar wind plasma. This is because the southward IMF component enhances the coupling between the solar wind and the magnetosphere/ionosphere system.
The level of the geomagnetic activity is measured using ground-based magnetometer recordings which can be used to study the longer trends in the solar activity. Variability in the geomagnetic activity can be from Sun cycles that are reflected in the solar wind/IMF. A 22-year double-solar-cycle variation in geomagnetic activity was identified. Activity is higher in the second half of even-numbered solar cycles and in the first half of odd-numbered cycles. The 11-year variability of geomagnetic activity suggest that the activity can be divided into three peaks:

[ saturnian magnetosphere] [Magnetosphere Moviemagneticfield_mpeg.mpg] [Magnetosphere] [Magnetosphere] [Magnetosphere Movierecon.mpeg] [nnnnnnnMagnetosphere Moviemagneticfield_mpeg.mpg]

Above: Magnetosphere Animation - As plasma from a solar storm impacts the Earth's magnetic field, oxygen ions are immediately ejected from the polar Ionosphere in response to the bursts of heating caused by the massive electrical current generated. The ejected ions flow outwrd along Earth's magnetic field lines toward the geotail. The pressure from the solar wind stretches the magnetic field toward the night-side of the Earth like a rubberband. When the stretching becomes too great, the night-side magnetosphere snaps back toward the Earth, carrying the ejected ions from the ionosphere with it like an enormous slingshot. These ions, now accelerated to enormous velocities (about 2,500 miles or 4,000 km/per second), appear immediately in the auroa and in the cloud of hot plasma that encircles the Earth during space storms.
[Magnetosphere Movie] [Ion Outflow Movie] [Expelled Ion Flow] [Auroral Circuit Movie] [IMAGE Spacecraft Movie]
1) Shortly before sunspot maximum. Linked with transient solar activity, and seen with relatively larger amplitude in ring current (storm) activity than in substorm activity. 2) About 2 years after sunspot maximum. Largest peak compound of transient and recurrent magnetic activity (the former dominating?). 3) Descending phase of the solar cycle. Largely recurrent, and seen with larger amplitude in substorm activity than in ring current (storm) activity. See how the two peaks, one somewhat ahead or at solar maximum and the other 2 or 3 years after it, can be seen in the SSC frequency. the 1.3 year variability The Earth's orbit around the Sun taking it to different solar latitudes (annual variability) The Earth's orbit around the Sun that changes the orientation of relevant coordinate systems (semi-annual variation) Rotation of the Sun around its axis, which can lead to periodicities at T = 27 days and T = 13-14 days this activity is called "recurrent" as opposed to "transient" that the other types are These effects will be discussed more below. 22-year variability The 11-year variability 1.3-year variability The 1.3-1.4-year variability originating from the Sun has been observed in the geomagnetic or auroral data by, e.g., Shapiro (1967), Silverman and Shapiro (1983), and Paularena et al. (1995). Annual variability The annual geomagnetic variation relates to the Earth's orbit. Due to the 7.2 degrees tilt of the solar rotation axis with respect to the normal of ecliptic, the Earth reaches the highest northern and southern heliographic latitude (where solar wind speed is higher) on September 6 and March 5, respectively, and crosses the equator twice a year between these dates. Thus, when observed from Earth, one should expect a semiannual variation in solar wind speed with maxima around these dates. However, annual variation is often more clear (e.g., Bolton, 1990), and this is because the solar wind distribution is asymmetric or shifted with respect to equator (Zieger and Mursula, 1998). Semi-annual variability The semi-annual variation has been attributed to a IMF-effect (Russell-McPherron, 1973): as the Earth orbits around the Sun, southward IMF component is statistically more likely twice a year, increasing the coupling between the solar wind and magnetosphere. As a result, more storms occur during equinoctial months than during the solstitial months. Recurrent activity The relationship between geomagnetic/auroral activity and solar rotation period of 27 days was noted well before space age (e.g., Broun, 1876; Maunder, 1905). This recurrent storm activity is due to coronal holes that cause fast solar wind streams (term M-region was used earlier; see also Crooker and Cliver, 1994). In addition, long intervals exists when two high-speed streams per solar rotation can be seen (e.g., Gosling et al., 1976), creating a 13.5-day periodicity. See, e.g., Mursula and Zieger (1996,1998) for more discussion about the matter.

The Magnetosphere as a Magnetic Trap

[Earth Magnetosphere]

The blue cavity represents the magnetosphere. The red area denotes the region where a large amount of charged particles reside and intense electric currents flow within the magnetosphere. The Cluster satellites encountered the flow reversal region in the magnetotail, on the nightside of the magnetosphere.
When an astronomical object has a magnetic field and an atmosphere, it is commonplace for ions to form a plasma that is trapped in the magnetic field. When the plasma tries to flow through the magnetic field, eddy currents form in the plasma and resist the motion. Because of this magnetic trap, the combination of magnetic field and plasma behaves like a fluid dripping from springy magnetic field lines.
Computer simulations of the magnetosphere that show the plasma and field lines have the shape of a hairy comet or spheroid. This combination of magnetic field and plasma is the magnetosphere.

The ions are usually formed as sunlight, especially ultraviolet, hits the upper atmosphere.
As planets get farther from the Sun, their magnetospheres therefore become less dense, and less active. Objects that lack a magnetic field, such as the moon, lack a magnetosphere.

[This implies that the outer vortex is a magnetism or plasma more subtle and undetectable. Closer to the planet it becomes the detectable magnetosphere. If the satellite has open vortex however, this may not reach the surface for many miles.

("The moon hath a vortex surrounding it, but being an open vortex turneth not the moon.")]

Objects that lack atmosphere also lack a magnetosphere because no ions can form. [But is not plasma ubiquitous? In the case of the moon, maybe it's that the magnetic field does not reach up to the surface that it lacks. Further out maybe there is a suble (less dense) formation in local plasma.]

The magnetic field in the tail points towards the Earth in the northern half and away in the southern half, this geometry being supported by a cross-tail current (neutral sheet).
The magnetopause is formed at a distance where the solar wind dynamic pressure equals the magnetic pressure of Earth's field. At this location, typically around 8 - 11 RE away on the Earth-Sun line, a large scale duskward current develops in the dayside magnetopause to cancel the Earth's field outside.


At the same time, the dipole field inside is increased, being now about two times the nominal dipole value. Similar current flows around the magnetotail, but there the direction has to be reversed in order to cancel the field outside. This current is closed via the cross-tail current. The thickness of the current layer is typically from several hundred to a thousand kilometers.
The magnetosphere presented above is of closed type. Even if simple, it can describe some dynamic events relating to Sun-Earth connection. However, when the effects of interplanetary magnetic field are taken into account, the magnetic reconnection complicates the physics of the magnetopause considerably by "opening" up the magnetosphere.

Convective Verses Co- Rotating Plasma Flow

[magnetosphere] The sketchs left and below illustrate the flow of charged particles in the equatorial plane of the magnetosphere. The interaction of the solar wind with the magnetosphere (through reconnection and viscous processes) results in a bulk flow of plasma down the magnetotail. This flow is referred to as "convection," although this term is really a misnomer because convection is a thermal process and the flow of plasma is not, being governed instead by large-scale electric and magnetic fields.
In the plasma sheet, the direction of the convective flow is sunward, perpendicular both to the direction of the Earth's magnetic field (out of the screen) and to the direction (dawn-to-dusk) of the electric field imposed on the magnetosphere by the solar wind interaction. (The motion of the plasma perpendicular to both the electric and magnetic fields is known as "E-cross-B drift.")


As coupling between the solar wind and the magnetosphere intensifies, sunward convection increases, and the boundary separating the convective and co-rotational flow regimes (known as the "separatrix") moves inward, freeing some of the plasma previously bound on "closed" Earth-encircling trajectories to follow "open" convective paths toward the dayside magnetopause. Weakening of convection enlarges the region of near-Earth plasma that co-rotates with the Earth and allows the magnetic field lines emptied of plasma during periods of high convection to refill.

The magnetotail is formed by tail lobes (on open polar cap) and the plasma sheet (closed nightside auroral field lines). In the inner magnetosphere we have plasmasphere mapping to mid- and low-latitudes. Overlapping both plasmasphere and inner plasma sheet are radiation belts and ring current.


The Sun/solar wind, magnetosphere, ionosphere, and upper atmosphere (thermosphere) are variously coupled to each other.

The coupling between the solar wind and the magnetosphere is via a magnetic reconnection process between the IMF component and the geomagnetic field. It creates the large scale magnetospheric convection electric field responsible for geomagnetic activity.
Ionosphere and magnetosphere are closely linked together via magnetic field lines. Magnetospheric electric fields map down to the ionosphere, creating plasma convection, frictional heating and plasma instabilities. Auroral particle precipitation ionizes the high latitude atmosphere during nighttime, and heat can be conducted from the magnetosphere down to the ionosphere.
Collisions between the convecting ionospheric plasma and the neutral atmosphere leads to generation of neutral winds and Joule heating of the neutral gas. Furthermore, the role of the newly discovered high-altitude atmospheric flashes in the ionospheric physics is still unknown.
The two main sources of magnetospheric electric fields are the solar wind related, dawn-to-dusk directed ("convection") field, and the co-rotation electric field related to the rotation of the Earth. The electric fields have a strong effect on the drift paths of the magnetospheric plasma.

Convection field


In the open magnetosphere model (1961), reconnection (or merging) of the interplanetary and geomagnetic field lines partially opens Earth´s magnetic field to the solar wind. For this to happen, the field lines must be oppositely directed: a southward interplanetary magnetic field (IMF) is thus needed to open Earth's closed dayside magnetic fields.
The antisunward magnetospheric convection is produced when the reconnected, open field lines are swept over the polar caps at the solar wind speed. The dawn-to-dusk solar wind electric field maps along the field lines, and an antisunward drift of plasma is formed also in the polar cap ionosphere.

When the northern and southern hemispheric field lines are streched into a magnetic tail by the solar wind, they eventually reconnect with each other deep in the antisunward region. This magnetic geometry has a tension that exerts a force on the plasma. Together with the pressure gradient and the potential difference applied across the magnetosphere by the flowing solar wind, these forces produce motion of the magnetospheric plasma on closed field lines towards the Sun, and an associated dawn- to-dusk magnetospheric electric field in the tail.
The mapping of this electric field into the ionosphere produce a dusk-to-dawn electric field and sunward plasma flow in the auroral zone: the familiar two-cell pattern of ionospheric convection is formed. If the southward IMF periods continues for several hours, the magnetosphere reaches a steady-state like configuration called steady magnetospheric convection
Note that when the plasma flows toward Earth because of the convection field, a zonal charge separation opposing the field is created as electrons drift dawnward and protons duskward around the Earth. The inner magnetosphere is thus shielded from the magnetospheric electric field, and the electric field due to the rotation of the Earth is dominating. Inside this region, called the plasmasphere, cool dense plasma is flowing in concentric circles around the Earth.

The Plasma sheet

Plasma sheet is the region of closed field lines in the equatorial magnetotail. Plasma sheet is typically divided into plasma sheet and plasma sheet boundary layer (PSBL), the latter being at higher latitudes adjacent to the tail lobes. It is also divided into two parts by the cross-tail current sheet in the equatorial plane. However, as the plasma sheet extends from the magnetotail to the geosynchronous orbit, the effects of the current are not as important in the inner plasma sheet as further tailward, and the magnetic field geometry has a transition region between the inner dipolar form and outer tail like field.

[The geostationary or geosynchronous orbit is located at approximately 6.6 RE geocentric distance in the geographical equatorial plane. In it, centrifugal force just balances gravity for a spacecraft that is in a circular orbit with a period of one orbit per day (i.e., at fixed geographic longitude).
The geosynchronous orbit tends to skim the inner boundary of the plasma sheet. This means that the surrounding plasma/magnetic field region varies a lot with the magnetic activity. The energetic electron fluxes at the geosynchronous orbit have been divided into two populations:
Hard: 300-2000 keV, Temperature=200 keV,
and Soft: 30-300 keV, T=25 keV, ]

Plasma sheet is a very important region for auroral physics, since the night time auroral oval maps to it.

Plasma sheet particles are hot, having energies in the keV range. Plasma density is a slowly varying function of time, correlating with the solar wind density. This indicates that solar wind is - at least partly - providing the plasma. Ion temperature is about seven times the electron temperature.
Because of the magnetospheric, large scale convection electric field, plasma is in continuous movement both toward Earth and toward the central cross-tail current region from tail lobes. At the inner plasma sheet boundary electrons and ions are on different convection paths, and electron plasma sheet does not always quite reach the geosynchronous orbit, while the ion plasma sheet does.

During increased geomagnetic activity, O+ ion dominates in the inner magnetosphere. This is evident both in storms, and ring current. These ions flow upward from the ionosphere.


[ Magnetoshere energy flow]

Figure showing a north-south section through the structures that usually extend several hundreds of kilometers in the east-west direction. The blue lines represent the auroral current system. Together with the ionospheric closure current and the magnetospheric generator these form the complete auroral current circuit.
Magnetometers, which measure electric currents in the upper atmosphere, and their successors have played the role that barometers did for early weather forecasters. The pattern of pressure changes the instruments recorded tracked the passage of storms in the atmosphere. Now, it is storms in the magnetosphere that are recorded.

[ Magnetoshere energy flow] The "cusp" which separates the magnetosphere's crown and tail is responsible for auroras. This is because it is at the cusp that magnetic field-lines stream down towards the ground, acting as paths for electrons and protons that have slipped past the bow shock. When these particles hit the upper atmosphere they generate light in the same way that electrons from the cathode of an old-fashioned television set do when they hit the phosphorescent dots of the screen.
The auroras borealis and australis are the result of particles streaming in from the tail. But particles come in from the crown, as well, forming invisible daytime auroras.
The Sondrestrom Upper Atmospheric Research Facility has a 32-metre-wide radar dish that measures conductivity from an altitude of 60km to 600km and has helped define the cusp's circuitry. That is important because, although it is not technically part of the atmosphere, the plasma of charged particles in the magnetosphere experiences what might be referred to as weather. Like the weather on Earth, this space weather has consequences. If it gets nasty, communications satellites may be knocked out and radio communications within the atmosphere disrupted.

Because of the Sun 's UV radiation, Earth 's upper atmosphere is partly (0.1% or less) ionized plasma at altitudes of 70-1500 km. This region, the ionosphere, is coupled to both the magnetosphere and the neutral atmosphere. It is of great practical importance because of its effect on radio waves.
The existense of a conducting layer in the upper atmosphere results in interesting phenomena. A natural resonator is formed between the nearly perfectly conducting terrestrial surface and the ionosphere. Broadband electromagnetic impulses, like those from lightning flashes, fill this cavity, and create globally the so-called Schumann resonances at frequencies of 7.8, 14, 20, 26, 33, 39, and 45 Hz

Ionospheric densities are higher during solar maximum years than during the minimum years.
Ionospheric electric fields are the main result of the coupling between the magnetosphere and ionosphere. While at low-latitudes the ionospheric plasma is co-rotating with the Earth, at higher latitudes it is convecting under the influence of the large scale magnetospheric electric field mapped to low altitudes.

The convection pattern leads to ionospheric Hall currents and along the auroral oval so-called convection electrojets are formed at about 100 km altitude: eastward electrojet on the duskside, westward on the dawnside.

Magnetic Field Reconnection

The concept of merging or reconnection of magnetic field lines is widely used although the physics behind the process are still under debate. The concept was developed to explain particle acceleration in solar flares (1946). The basic idea behind reconnection is that (partly) antiparallel magnetic field lines can, when meeting, merge together and produce two topologically totally different field lines.
Reconnection is thought to be the main link in the solar wind - magnetosphere coupling process, occurring at the dayside magnetopause between southward directed IMF and the northward directed geomagnetic field. [I take this to mean the lines that arc from the sun's poles downward to the earth's pole vicinity (not the solar wind). If so what would pole reversal do?] It is the main process that transports mass, momentum, and energy from the solar wind into the magnetosphere, and it drives the large scale magnetospheric convection. There are several reasons to believe the existence of such a process:
there is a clear correlation between the IMF direction and geomagnetic activity
some measurements indicate the presence of unexplained processes at the magnetopause
In addition to the dayside reconnection, similar process should be occurring in the far tail. Finally, some substorm models are also based on reconnection. This is quite natural, since the magnetic field lines above and below the cross-tail current sheet are oppositely directed, and the plasma sheet is typically thinning during the substorm growth phase.
Reconnection allows the magnetic field of the Sun to connect to Earth's field, allowing energy and matter to flow from one to the other. The solar wind flows into Earth's magnetosphere through a narrow valve-like region a quarter of a million miles downwind of the planet, in a region known as the magnetic tail.

[ Magnetoshere energy flow]

Reconnection happens where it says engergy coupling region.

Depending upon the orientation of the solar wind and Earth's magnetic field, that valve opens and closes to allow plasma and energy from the Sun to enter Earth's space. On the sunlit side of Earth, the solar wind pushes Earth's magnetic field, but the plasma barely penetrates Earth's magnetic shell.

It is in the distant reconnection region of the tail, on the night side of Earth, where the solar wind enters the magnetosphere. The flow of solar wind into the tail of the magnetosphere fills Earth's space with plasma and energy.
This energy is stored like a battery until it is eventually released in bursts that cause auroras and other space weather phenomena. Magnetic reconnection was proposed more than forty years ago as the key process that allows this flow of solar wind into the magnetosphere.
During reconnection, magnetic fields that are heading in opposite directions -- having opposite north or south polarities -- break and connect to each other.

In April 1999, the "Wind" sattelite flew right through the reconnection region as the process was occurring. While flying tailward through the magnetosphere (away from Earth), Wind's instruments detected jets of plasma racing toward Earth. Part-way through the journey, the jets stopped and Wind detected unusual electric currents and magnetic signatures that were predicted to occur at the point of reconnection. Some time later, as Wind kept flying away from Earth, the spacecraft detected that jets of plasma flow in the exact opposite direction of the previous flows, racing away from the planet.
The event was comparable to a plane flying through the eerie, calm eye of a hurricane.
"Reconnection is one of the fundamental physical processes in the universe. It occurs in so many places in the universe, yet the only place we can observe it directly in a natural environment is in our magnetosphere. It is absolutely crucial for understanding how the Sun connects to the Earth. This is how you populate the magnetosphere with plasma.
The direct observation of reconnection has implications for many fields of physics. Reconnection on the Sun likely plays a role in the development of solar flares and of coronal mass ejections. Reconnection likely plays a role in the interaction of neighboring stars. And observations of reconnection in nature may aid the study of nuclear fusion and other plasma processes in the laboratory.

Plasmoids/flux ropes [Or Vortices]

Tailward fast plasma flows with dipolar BZ signatures (north-then-south turning of Magnetic Field (B)) observed within plasma sheet are called plasmoids. Most plasmoids have also helical magnetic field structures (large By fields), called "flux ropes".
Observations of plasmoids are highly correlated with substorm onsets. Accordingly, their existence is considered to support substorm models based on reconnection. This is because reconnection seems to be the most obvious mechanism for plasmoid creation. Plasmoids originate from the distance of about 20-30 RE, and have been observed up to about 200 RE downtail; tailward speeds are several hundreds of km/s.
Of the heavier ions observed within the plasmoids, most of the oxygen ions are singly charged (O+, ionospheric origin), and most of the helium ions are doubly charged (He++, solar wind origin).

Deeper Analysis

The basic nature of the interaction between the solar wind and the Earth's magnetic field, leading to the concept of the Earth's magnetosphere, is based on two theoretical principles. The first concerns the way in which plasmas and magnetic fields interact; they behave, approximately, as if they are "frozen" together. As a result of this freezing together, magnetic fields are transported by flowing plasmas; the field lines are bent and twisted as the flow bends and twists.
The interplanetary magnetic field is wound into a large spiral structure by the Sun's rotation, and near the Earth it has a strength of about 5 nanoteslas (nT). This is a rather weak field, about one ten thousandth of the field at the Earth's surface, but nevertheless, it plays a crucial role in the Earth's interaction with the solar wind.

The second principle concerns the force that the magnetic field exerts on the plasma, which usually opposes the bending and twisting of the field, or its compression, in the frozen-in flow. There are two components of this force. First, the field exerts an effective pressure on the plasma proportional to the square of the field strength. This force resists compressions or rarefactions of the magnetic field. Second, bent field lines exert a tension force on the plasma like stretched rubber bands. This force resists the bending and twisting of field lines.
Applying the first of these ideas to the interaction between the solar wind and the Earth, we recognize that the solar wind plasma is frozen to the interplanetary magnetic field, and the Earth's plasma (for example, from the ionosphere) to the Earth's field. When these plasmas meet each other, therefore, they do not mix, but instead they form distinct regions separated by a thin boundary. The solar wind thus confines the Earth's magnetic field to a cavity surrounding the planet, forming the Earth's magnetosphere.


The structure of the Earth's magnetosphere in the noon-midnight meridian plane, showing a) the Chapman-Ferraro closed magnetosphere based on strict application of the frozen-in approximation, and b) the Dungey open magnetosphere, in which there is an essential breakdown of frozen-in flow at the dayside magnetopause and in the tail leading to the occurrence of reconnection. The arrowed solid lines indicate magnetic field lines, the arrowed dashed lines plasma streamlines, and the heavy long-dashed lines the principal boundaries (the bow shock and magnetopause). The circled dots marked E in b) indicate the electric field associated with the flow, which is perpendicular to the flow and the field, and given in magnitude by their product.

The size of the cavity is then determined by pressure balance at the boundary between the solar wind on one side, and the magnetic pressure of the planetary field on the other. Given a planetary "bar magnet" field that produces a field strength of about 30,000 nT at the Earth's surface at the equator, estimates place the boundary, called the magnetopause, at a geocentric distance of about 10 Earth radii on the upstream (day) side, and this is where it is generally observed. (The Earth's radius is about 6400 km.)
On the downstream (night) side the cavity extends into a long magnetic tail. Across the magnetopause the magnetic field usually undergoes a sharp change in both strength and direction. Ampere's law then tells us that a sheet of electrical current must flow in the plasma in this interface, called the Chapman-Ferraro current. A shock wave also stands in the flow upstream of the cavity, which forms because the speed of the solar wind relative to the Earth is much faster than that of wave propagation within it. Across the shock the flow is slowed, compressed, and heated, forming a layer of turbulent plasma outside the magnetopause called the magnetosheath.
Inside the cavity the terrestrial plasma will approximately rotate with the Earth. This will occur because the Earth's field lines are frozen into the ionospheric plasma. There, co-rotation is enforced in the absence of other driving processes, by collisions between ions and atmospheric neutrals at heights of about 120-140 kilometers.

Dungey's Open Magnetosphere

The interplanetary magnetic field is compressed against the magnetopause and draped over it by the flow, but ultimately the field lines slip around the "sides" of the magnetosphere, frozen into the magnetosheath plasma. However, the "frozen-in" picture is only an approximation, and under some circumstances it will break down. One of those circumstances occurs when high current densities are present in the plasma, and we have seen that large currents will occur at the magnetopause boundary.
When the frozen-in condition is relaxed, the field will diffuse relative to the plasma in the magnetopause, allowing the interplanetary and terrestrial field lines to connect through the boundary. Dungey called this process magnetic reconnection. The distended loops of "open" magnetic flux formed by reconnection exert a magnetic tension force that accelerates the plasma in the boundary north and south away from the site where reconnection takes place, thus causing the open tubes to contract over the magnetopause toward the poles.
The open tubes are then carried downstream by the magnetosheath flow, and stretched into a long cylindrical tail. Eventually, the open tubes close again by reconnecting in the center of the tail. This process forms distended closed flux tubes on one side of the tail reconnection site, which contract back toward the Earth and eventually flow to the dayside where the process can repeat. On the other side, "disconnected" field lines accelerate the tail plasma back into the solar wind. The key feature of the "open" magnetosphere is therefore the cyclical flow excited in the interior by these reconnection processes.


The plasma flow streamlines associated with the Dungey flow cycle (arrowed solid lines) and the main zones where plasma particles of differing characteristics flow down the Earth's magnetic field lines from the magnetosphere into the upper atmosphere and ionosphere. The interior heavy dashed circle shows the boundary between open field lines at high latitudes and closed field lines at lower latitudes (compare with the noon-midnight cross-section in Figure 1b)..

The ionospheric image of the magnetospheric flow shows a view looking down onto the north pole of the Earth. It consists of twin flow vortices with open field lines that flow away from the Sun over the polar cap and closed field lines that flow toward the Sun at lower latitudes. Typical ionospheric flow speeds are several hundred meters per second. The overall flow cycle time is about 12 hours. From this the length of the tail can be estimated to be about 1000 Earth radii [16.6 times the distance to the moon].
The most important feature of the magnetosphere-ionosphere flow, however, is that its strength is modulated by variations in the direction and strength of the interplanetary magnetic field. The dayside reconnection rate, and hence the magnetic flux throughput in the magnetosphere, is strong when the interplanetary field points south, opposite to the equatorial field of the Earth. When the interplanetary field points north, however, equatorial reconnection cannot occur, and the cyclical flow described above dies away.
This dependence of the flow on the direction of the interplanetary field distinguishes Dungey's open magnetosphere from other possibilities (for example, flow excited in a closed Chapman-Ferraro system by "viscous" forces at the magnetopause), and has been demonstrated by many studies over the past 30 years. It is important to realize, however, that the magnetic flux throughput in the system, even at its strongest, amounts to no more than about 20% of the interplanetary magnetic flux brought up to the dayside magnetosphere by the solar wind. Most of the interplanetary flux is deflected around the magnetosphere. However, it is the breakdown of this picture at the 10-20% level due to reconnection at the magnetopause that is critical to the Earth's magnetospheric dynamics. The contribution to the flux transport by other nonreconnection mechanisms appears to be much smaller than this.
The cyclical flow driven by the solar wind is not, however, the only source of flow in the Earth's magnetosphere. In the absence of other effects the plasma would tend to rotate around with the Earth.
When the flows caused by the Dungey cycle are added to the corotation flow, it is found that the Dungey cycle flows dominate in the outer part of the magnetosphere, while the corotation flow is confined to a small central core of dipole flux tubes, which typically extend in the equatorial plane to 4-6 Earth radii. This latter region is filled to relatively high densities with cold hydrogen/helium plasma from the ionosphere, forming a region called the plasmasphere. Outside this region the cold plasma density is much lower because of heating and loss of the ionospheric plasma during each cycle of the Dungey flow, and the medium is instead characterized by the presence of hot and tenuous plasma that is accelerated in the tail on closed field lines downstream from the tail reconnection site, and is then transported inward toward the Earth.
The size of the plasmasphere is not constant, however. The corotating region extends further from Earth than the average during intervals of weak Dungey cycle convection (northward interplanetary fields), and the ionosphere fills the outer flux tubes of this region toward equilibrium values while this condition persists. The corotating region shrinks when the Dungey cycle flow increases again (southward interplanetary fields), and the cold plasma that accumulated in the outer region is stripped away and flows to the dayside magnetopause, where much of it is heated and flows out into the solar wind. It is replaced by hot plasma flowing in from the tail.

Magnetospheric Substorms

The variability of the magnetospheric flow on timescales of minutes and hours that is associated with changes in the direction of the interplanetary magnetic field is a key feature. However, observations show that when dayside reconnection is enhanced, for example by a southward turn of the interplanetary field, the magnetosphere generally does not evolve smoothly toward a new steady state of enhanced convection. Instead, the system, particularly the tail, undergoes a characteristic evolution on a 1-2 hour timescale, called a magnetospheric substorm.
Suppose the magnetosphere is initially in a state of low flow during an interval of northward interplanetary field, and that the interplanetary field then turns south.
Reconnection starts at the magnetopause, stripping magnetic flux off the dayside and adding it to the tail, so that the dayside magnetopause moves inward (up to an Earth radius), while the tail magnetopause moves out (and the field strength inside increases). These changes are accompanied by an excitation of the large-scale flow as the system adjusts to the altered field configuration.
During this interval, called the "growth phase" of the substorm, the field lines in the tail become very distended and nondipolar. This development of the tail continues steadily over periods of several tens of minutes. Then, on a timescale of just a minute or two, these distended field lines collapse inward toward the Earth near the equator, and outward at higher latitudes, to a more dipolar form, (as shown in (b) below).
Why the field suddenly reconfigures in this manner is at present unknown, and is the subject of much research worldwide.


The development of the nightside tail magnetic field during the growth and expansion phases of a substorm. Sketch a) shows the development of distended nondipolar field lines in the near-Earth tail during the growth phase, b) the onset of the field disruption at the beginning of the expansion phase and the rapid return of the inner tail field to a more dipolar form, while c) shows the down-tail propagation of this disruption and the subsequent induction of tail reconnection and plasmoid formation at larger distances from Earth.

As the tail field lines collapse, the plasma that they contain is strongly heated and compressed. This produces a sudden intense flux of electrons at the top of the atmosphere at the feet of the field lines concerned, producing a brilliant auroral display as the atmospheric atoms are excited by collisions with the electrons at altitudes above 100 km, and then radiate. The upper atmosphere also becomes much more strongly ionized at these altitudes than before, and hence more electrically conducting, and strong electric currents flow whose magnetic effects can be observed on the ground.
The tail field collapse usually starts in a restricted sector near the midnight meridian in the near-Earth end of the tail, and then propagates both across and down the tail, sometimes in a series of steps. In the upper atmosphere the area of bright auroras and strong electric currents therefore expands to the east and west as well as poleward, such that this interval is called the "expansion phase" of the substorm.
This field collapse often induces the onset of reconnection in the tail at distances of 20-40 Earth radii as it propagates downtail. When this happens, closed tail field lines containing hot plasma are "pinched off" to form a closed-loop "plasmoid" that propagates downtail and into the solar wind at speeds of 400-800 kilometers per second, as (as depicted in (c) above). Continued reconnection in the near-Earth tail then closes open tail field lines. After a few tens of minutes, however, the reconnection rate slackens and the reconnection region moves back down the tail, signaling the end of expansion.
The subsequent "recovery phase" of the substorm typically lasts for many tens of minutes. During this period the system responds and adjusts to the input of magnetic flux and hot plasma on the nightside during the expansion phase.
The above sequence of events typically follows a southward turning of the interplanetary magnetic field that lasts for at least a few tens of minutes. Several such intervals and several substorms can occur in one day. If the southward field persists for significantly longer, however, the system often evolves through a series of substorm cycles each lasting about an hour.
The hot tail plasma is then driven deep into the inner magnetosphere by the enhanced convection, this constituting the main characteristic of a magnetic storm proper. The positively charged ions in this plasma drift westward around the Earth, and the negative electrons drift eastward, such that both contribute to a westward-directed ring of current that encircles the Earth at distances, typically, of several Earth radii. The magnetic field produced by this current causes a worldwide decrease in the field strength on the ground at low and middle latitudes.

The Ring Current


Image of a portion of the Ring Current with Earth superimposed. The current is not smooth, and often does not completely encircle the equatorial zone of Earth. It is more prominent on the night time side (right in this figure), and as it moves into the dayside it breaks up and vanishes, possibly by losing particles into the magnetopause region.

A ring current is an electric current carried by charged particles trapped in a planet's magnetosphere. It is caused by the longitudinal drift of energetic (10-200 keV) particles.
Earth's ring current is responsible for geomagnetic storms. The ring current system consists of a band, at a distance of 3-5 RE [11,889 - 19,815 miles], which lies in the equatorial plane and circulates clockwise around the Earth (when viewed from the north). The particles of this region produce a magnetic field in opposition to the Earth's magnetic field and so an Earthly observer would observe a decrease in the magnetic field in this area.

The ring current energy is mainly carried by the ions, most of which are protons. However, one also sees alpha particles in the ring current, a type of ion that is plentiful in the solar wind. In addition, a certain percentage are O+ oxygen ions, similar to those in the ionosphere of Earth, though much more energetic. This mixture of ions suggests that ring current particles probably come from more than one source. Ring current particle energies range from 0.05 MeV to 1 MeV.

During a geomagnetic storm, the number of particles in the ring current will increase. At the same time there is a decrease in the geomagnetic field.

The motion of energetic ions and electrons through space is strongly constrained by the local magnetic field. The basic mode is rotation around magnetic field lines, while at the same time sliding along those lines, giving the particles a spiral trajectory.
On typical field lines, attached to the Earth at both ends, such motion would soon lead the particles into the atmosphere, where they would collide and lose their energy. However, an additional feature of trapped motion usually prevents this from happening: the sliding motion slows down as the particle moves into regions where the magnetic field is strong, and it may even stop and reverse. It is as if the particles were repelled from such regions, an interesting contrast with iron, which is attracted to where the magnetic field is strong.
The magnetic force is much stronger near the Earth than far away, and on any field line it is greatest at the ends, where the line enters the atmosphere. Thus electrons and ions can remain trapped for a long time, bouncing back and forth from one hemisphere to the other. In this way the Earth holds on to its radiation belts.
In addition to spiraling and bouncing, the trapped particles also slowly drift from one field line to another one like it, gradually going all the way around Earth. Ions drift one way (clockwise, viewed from north), electrons the other, and in either drift, the motion of electric charges is equivalent to an electric current circling the Earth clockwise. That is the so-called ring current, whose magnetic field slightly weakens the field observed over most of the Earth's surface. During magnetic storms the ring current receives many additional ions and electrons from the nightside "tail" of the magnetosphere and its effect increases, though at the Earth's surface it is always very small, only rarely exceeding 1% of the total magnetic field intensity


Van Allan Belt

[Van Allan Belt] The Van Allen radiation belt is a torus of energetic charged particles around Earth, trapped by Earth's magnetic field. The presence of a radiation belt had been theorized prior to the Space Age
It consists of two belts around Earth, the inner radiation belt and the outer radiation belt. The particles are distributed such that the inner belt consists mostly of protons while the outer belt consists mostly of electrons. Within these belts are particles capable of penetrating 1 millimeter of lead.
The Sun does not support long-term radiation belts. The atmosphere limits the belts particles to regions above 200-1000 km. The belts are confined to an area which extends about 65° from the celestial equator.

[trapped particles] Van Allen belts are a result of the collision of Earth's magnetic field with the solar wind. Radiation from the solar wind then becomes trapped within the magnetosphere. The trapped particles are repelled from regions of stronger magnetic field, where field lines converge. This causes the particle to bounce back or "mirror." .
Without this sort of "mirroring," ions and electrons would not be trapped in the Earth's magnetosphere, but would instead follow their guiding field lines into the atmosphere, where they would be absorbed and become lost. What happens instead is that every time a trapped particle approaches Earth, it is reflected back. It is thus confined to the more distant section of the field line.
Now and then a violent outburst, known as a magnetic storm, drives tail plasma earthward, into the near-Earth magnetosphere. Electric fields (voltage differences) are essential to this process, to help tail particles break into trapped orbits and to drive them to higher energies. When the outburst ends and the electric field dies away, the particles find themselves locked in trapped orbits of the ring current and the outer radiation belt. Lesser outbursts, known as magnetospheric substorms, occur quite frequently.
Whereas the inner belt is marked by great stability, the ring current and outer belt constantly change. Sooner or later the particles are lost, e.g. by collision with the rarefied gas of the outermost atmosphere, and on the other hand, new ones are frequently injected from the tail. The electric fields which inject the new particles can also draw oxygen ions upwards from the ionosphere, and the ring current contains such ions, typically a few percent of the total, more during magnetic storms.

The Inner Belt

The inner radiation belt extends over altitudes of 650-6,300 km (1.1 - 3.3 RE). This ring is most concentrated in the Earth's equatorial plane. It consists mostly of protons on the order of 10-50 MeV (Flux maximum at about 2 RE), a by-product of collisions between cosmic ray ions and atoms of the atmosphere. The belt also contains electrons, low-energy protons, and oxygen atoms with energies of 1-100 keV. When these electrons strike the atmosphere they cause the polar aurora.
The intensity of the belt fluctuates, partly due to the influence of the solar cycle, and is strongest between 2-5,000 km.
The number of cosmic ray ions is relatively small and the inner belt therefore accumulates slowly, but because the trapped protons are very stable in this belt (with particle lifetimes of up to ten years), high intensities are reached as they build up over many years. The belt was discovered by a Geiger counter on board the Explorer 1 satellite built by James Van Allen.
The inner radiation belt owes its existence to the extraordinary stability of trapped orbits near the Earth. It is a by-product of the cosmic radiation, which by itself has a rather low intensity: the amount of energy received by Earth from cosmic rays is comparable to what it receives from starlight. Only by accumulating particles over the span of years does the inner belt reach its high intensity. [Can you believe this?]
Cosmic rays are fast positive ions, bombarding Earth from all directions, probably filling our entire galaxy. Though their numbers are small, the energy of each particle is quite high, so that when these ions smash into nuclei of atmospheric gases, fragments go flying off in different directions, some of them short-lived particles created by the collision. Most such fragments are absorbed by the atmosphere or by the ground, but a few are also splattered upwards, out of the atmosphere and into space.
If these are electrically charged, e.g. electrons or ions, they will often end up trapped by the Earth's magnetic field. None of these however lasts very long, since trapped orbits which rise from the atmosphere must sooner or later enter the atmosphere again.
Some of the fragments are however neutrons, particles similar to protons but without the electric charge; neutrons make up about half the weight of a typical atomic nucleus. Having no electric charge, neutrons are not affected by the Earth's magnetic field, and moving far too fast for gravity to hold them back, they usually escape into space.
The free neutron is however radioactive: within about 10 minutes it breaks up into a proton, which captures most of the energy, an electron and a massless neutrino. Ten minutes is a fairly long time for a fast particle, time enough for many neutrons to get halfway to Mars. However, decay times are spread out statistically, and while 10 minutes is the average, a few neutrons decay quite soon, while still inside the Earth's magnetic field. The energetic protons which then materialize are grabbed by the Earth's magnetic field, often on trapped orbits which do not return to the atmosphere, in which the proton can stay trapped for a rather long time. That is how the inner belt arises. [this sounds ridiculous]

The Outer Belt

The outer belt contains mainly electrons with energies up to 10 MeV. It is produced by injection and energization events following geomagnetic storms, which makes it much more dynamic than the inner belt (it is also subject to day-night variations). It has an equatorial distance of about 3 - 9 RE (10,000-65,000 km), with maximum for electrons above 1 MeV occurring at about X = 4 RE (14,500-19,000 km). 'Horns' of the outer belt dip sharply in towards the polar caps.
The outer belt is thought to consist of plasma trapped by the Earth's magnetosphere. There are very few particles of high energy within the outer belt. The electrons here have a high flux and along the outer edge and E > 40 Kev electrons can drop to normal interplanetary levels within about 100km (a decrease by a factor of 1000). This drop-off is a result of the solar wind.
The particle population of the outer belt is varied, containing electrons and various ions. Most of the ions are in the form of energetic protons, but a certain percentage are alpha particles and O+ oxygen ions, similar to those in the ionosphere but much more energetic.
The outer belt is larger and more diffuse than the inner, surrounded by a low-intensity region known as the ring current. Unlike the inner belt, the outer belt's particle population fluctuates widely and is generally weaker in intensity (less than 1 MeV), rising when magnetic storms inject fresh particles from the tail of the magnetosphere, and then falling off again.
The outer radiation belt is nowadays seen as part of the plasma trapped in the magnetosphere. The name "radiation belt" is usually applied to the more energetic part of that plasma population, e.g. ions of about 1 Mev of energy. The more numerous lower-energy particles are known as the "ring current", since they carry the current responsible for magnetic storms. Most of the ring current energy resides in the ions (typically, with 0.05 MeV) but energetic electrons can also be found.

[ two radiation belts]

Cross-section of the two radiation belts. The intensity contours are banana-shaped, because they follow magnetic field lines to which the particles are attached. We now know that outer-belt ions and electrons probably come from the long "magnetic tail" of stretched field lines on the night side of the magnetosphere.

A sudden increase in solar wind pressure can cause the radiation belts to change shape. In such an instance, particles on the sunward side of the planet will be carried inward (toward the planet), while particles on the far side of the planet will be carried further from the planet. This can give the radiation belts somewhat of a tear-drop shape. After such an incident, the belts tend to return to a more spherical shape.

The gas giant planets Jupiter, Saturn, Uranus and Neptune, all have intense magnetic fields with radiation belts similar to the Earth's outer belt.
Jupiter's belt is the strongest, and is affected by its large moon Io, which loads it with many ions of sulfur and sodium from the moon's volcanoes. Saturn seems to have an "inner belt" similar to the Earth's, probably produced by cosmic rays which eject neutrons from Saturn's planetary rings.

The Io Plasma Torus

[ torus]

Within Jupiter's magnetosphere, there is a significant amount of hot, ionized gas, or plasma. This plasma moves along with Jupiter's rotating magnetic field, sweeping charged particles off the surfaces of its moons as it passes them. Io has a particularly significant impact on Jupiter's magnetosphere. Io's volcanoes continually expel an enormous amount of particles into space, and these are swept up by Jupiter's magnetic field at a rate of 1,000 kg/sec.
This material becomes ionized in the magnetic field and forms a ring of plasma or doughnut-shaped track around Io's orbit called the Io Plasma Torus. The plasma consists mostly of oxygen and sulfur ions that emit radiation mostly in the extreme ultraviolet, but some emissions are observable by earth-based telescopes. Radiation levels within the plasma torus are extreme and pose a serious threat to spacecraft.
Of all the planets, only Jupiter gives off radio waves. This would indicate some active energy creation process exists.
The torus is believed to be the cause of Jupiter's radio waves. This doesn't have an explanation yet.

[ torus]

As Io circles around Jupiter and through the plasma torus, an enormous electrical current flows between them. Approximately 2 trillion watts of power is generated. The current follows the magnetic field lines to Jupiter's surface where it creates lightning in the upper atmosphere.
Voyager instruments observed auroral discharges, similar to Earth's northern lights,in the northern regions, in ultraviolet and visible light. Pioneer 10 and 11 didn't see the ultraviolet discharges during their encounters.The auroral discharges appear to be related to material from Io that spirals along magnetic field lines to fall into Jupiter's atmosphere

[ jupiters aurora]

The first black and white Hubble Space Telescope image (top left) shows the flux tube, where Io and Jupiter are linked by an electrical current of charged particles.
Volcanic emissions from Io flow along Jupiter's magnetic field lines, through Io, to Jupiter's north and south magnetic poles. In the second black and white image, auroral emissions are visible at Jupiter's north and south poles. The ultraviolet image below shows how the structure and appearance of Jupiter's aurora changes at it rotates.

[ aurora]

This image of Io was taken while the moon was in Jupiter's shadow. The vivid colors are the result of collisions between Io's atmospheric gases and charged particles trapped in Jupiter's magnetic field. The red and green colors are probably produced by mechanisms similar to those that produce the aurora in Earth's polar regions. The blue light indicates locations where dense plumes of volcanic vapor rise into space. These may be places where Io is electrically connected to Jupiter.

Jupiter's magnetosphere is the largest structure in the solar system. It is molded into a teardrop shape by a stream of energetic particles blowing away from the Sun called the solar wind. The side of the magnetosphere facing the Sun extends about 3 million kilometers from the planet, and its tail reaches out another 650 million kilometers, to the orbit of Saturn and beyond. If it were visible from Earth, it would appear several times larger in the sky than the full moon.

[ jupiters magnetosphere]

Jupiter's magnetic field is generated deep within the planet. Although its outer atmosphere is composed primarily of hydrogen gas, deep within the interior the pressure is so great that the hydrogen becomes a liquid. Because of the tremendous pressure, the electrons of the hydrogen atoms freely move from atom to atom, making it a very good conductor of electricity. Because of this property, it is referred to as liquid metallic hydrogen. Jupiter spins on its axis every 9.9 hours, generating convection currents in the liquid metallic hydrogen. This produces Jupiter's powerful magnetic field.

[ jupiters magnetosphere]

This image taken on Jan. 4 and 5, 2001 by the Ion and Neutral Camera on NASA's Cassini spacecraft, makes the huge magnetosphere surrounding Jupiter visible in a way never seen before. Jupiter's magnetic field has been sketched over the image. The disk of Jupiter is shown by the black circle, and the approximate position of the Io plasma torus is represented by the yellow circles.

Please now go to: Bits and Pieces Part 8

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[The Sun Part 4 ]
[The Sun Part 5 ]
[The Sun Part 6 ]