b Explain how a increase in cloud cover would affect the eva

b. Explain how a increase in cloud cover would affect the evaporation.

Solution

Solar radiation and temperature are the thermal (radiation and sensible heat energy) sources that cause water to evaporate from the earth\'s surface.

For a clear sky in the Northeast on the first day of summer, the maximum incoming (extraterrestrial) solar radiation potential provides enough energy to evaporate about a half inch of water per day. However, some of this solar energy is absorbed and diffused by clouds, some is reflected from soil, water, and plant surfaces (the albedo), and some goes into heating the atmosphere and the soil.

A heavy cloud cover in the lower atmosphere can significantly affect the amount of solar radiation that reaches the earth\'s surface. Since the incoming extraterrestrial solar radiation energy is reflected and diffused as it passes through the atmosphere, the net radiation potential reaching the earth\'s surface is much less. At the earth\'s surface, the potential evaporation and transpiration is about half to two-thirds the maximum, or generally around one-fourth inch of water per day when summer begins.