ABSTRACT
The primary causes of horizontal atmospheric air motion, or wind, are the uneven heating of the earth and its atmosphere by solar radiation and the earth’s rotation. The earth’s atmosphere reflects about 43% of the incident solar radiation back into space, absorbs about 17% of it in the lower portions of atmosphere, and transmits the remaining 40% to the surface of the earth, where much of it is then reradiated into the atmosphere. The radiation from the hot sun is at short wavelengths (0.15–4 μm) and passes readily through the atmosphere, while the radiation from the cooler earth is at longer wavelengths (5–20 ͘μm) and is readily absorbed by the water vapor in the atmosphere. Thus, the radiation from the earth is primarily responsible for the warmth of the atmosphere near the earth’s surface. Heat is also transferred from the earth’s surface to the atmosphere by conduction and convection.
