Chapter 20.1
Causes of Climate
Climate - the characteristic
weather for a region over a long period of time.
Temperature
and precipitation determine climate.
Temperature - determined
by latitude, altitude,
distance from an ocean, and the amount
of the sun's energy which is absorbed.
| Latitude and the tilt of the earth's axis determine the angle of the sun's rays. Direct rays provide more energy than slanted rays. The most direct rays strike the areas near the equator. As latitude increases (further north or south) the suns rays strike at more of an angle. |
| Altitude is the distance above sea level. Temperatures decrease as you go higher in altitude. This is because pressure decreases as you go higher, so molecules of air spread farther apart, less dense air cannot hold as much heat. |
| Distance from an ocean
influences temperature too. Water heats up and cools down more slowly
than land does. This keeps the temperatures of coastal areas moderate.
Surface ocean currents affect temperatures of coastal areas. Warm surface currents can warm an area. Cool surface currents can cool an area. |
Precipitation
-
winds and topography
affect the amount of precipitation an area receives.
| If prevailing winds blow from the water, then an area will receive a lot of rain. Where prevailing winds blow from the land, areas receive little rain. |
| Topography is surface
features of the land. Mountains affect precipitation. One side
of a mountainous region will have moist weather.
The plains and praries have little rain. |
