Wind Energy: Renewable Energy and the Environment, 3rd Edition

3   Wind Characteristics

3.1   GLOBAL CIRCULATION

The motion of the atmosphere can vary in distance and time from the very small to the very large (Table 3.1). There is an interaction between each of these scales and the flow of air is complex. Global circulation encloses eddies that enclose smaller eddies and the enclosures continue until finally the microscale is reached.

The two main factors in global circulation are solar radiation and the rotation of the Earth and Earth’s atmosphere. Seasonal variation is due to the tilt of the Earth’s axis to the plane of the Earth’s movement around the sun. Because solar radiation is greater per unit area when the sun is directly overhead, heat is transported from the regions near the equator toward the ...