GEOG 101 Lecture Notes - Lecture 20: Shortwave Radiation, Thermal Equator
Document Summary
Clouds reflect shortwave radiation back into space: earth"s surface then absorbs less of it, therefore, earth"s surface is cooler during cloudy days. Clouds act as a blanket: less longwave radiation from earth"s surface is able to escape into space, therefore, earth"s surface is warmer during cloudy night. Cold air is dense and heavy; it tends to sink to valley bottoms leaving the surrounding hillsides warmer: warmer hillsides = thermal belts, crop selection may be different on the hillside than in the valley bottom. There are 7 main factors which cause variations in temperature: referred to as climatic controls, latitude, at lower latitudes (i. e. near the equator), more shortwave radiation impacts the earth"s surface. Altitude: higher elevations experience cooler temperatures, temperature decreases with increasing altitude. There are fewer air molecules at higher elevation. This allows for radiation to more easily escape into space. Proximity to bodies of water: water keeps nearby land areas relatively warmer in autumn and cooler in.
