GEG 1301 Lecture Notes - Lecture 6: Atmospheric Circulation, Angular Velocity, Thermal Equator

• School: University of Ottawa
• Department: Geography
• Course: GEG 1301
• Professor: Denis Lacelle

Document Summary

Primary (global), secondary (migratory pressure systems), and tertiary (local) When only meridional circulation is considered (no rotation), a single cell model is created. When rotation is considered a three-cell model is more accurate. The increased angular velocity at the equator drives the separation into three cells by sinking of air masses when the difference between the velocities is too great. Rising air masses retain the velocity of the region where they were formed. Sinking air = high pressure at the surface, rising air = low pressure at the surface. Itcz (intertropical convergent zone) is also known as the thermal equator (highest temp) Low pressure belt, warm and rainy (lots of cloud cover), moves seasonally. By contrast, polar high pressure cells are cold and dry. Polar jetstream is much more powerful than the subtropical jetstream. Westerlies that tend to develop meridional (n-s) flow. Wind is the main factor that triggers and control surface ocean currents.