The Biophysical Environment

Atmospheric Processes, climatic components, climatic variation

Atmospheric Processes

Energy in the Atmosphere
-The earth’s main source of energy comes from incoming short wave radiation (insolation) from the sun.
- This controls earth’s climate, weather, water cycle and through the process of photosynthesis supports all life on earth

The amount of incoming solar radiation received at a particular location is determined by: the distance from the sun the latitude the length of day and night

Most solar radiation is absorbed, reflected or scattered as it passes through the atmosphere. Some is also reflected back into space by clouds.

The ratio between incoming radiation and the amount reflected back, can be expressed as a percentage known as the albedo. The albedo increases where human land use has resulted in decreased amounts of vegetation, which increases the risk of desertification

Albedo index
10% over oceans and dark soil
25% over grasslands
40% over desert
85% over snow

-Only 24% of the solar radiation reaches the earth’s surface.
-21% reaches the earth as diffused radiation.
-Incoming radiation is transformed into heat energy
- 94% of energy in the atmosphere is absorbed by water vapour and Co2 creating the natural greenhouse effect.

The Global Heat Budget The balance between incoming insolation and outgoing terrestrial radiation means that the earth’s temperature remains constant

Features of the Global Heat Budget include:
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