GEOG 1010 Lecture Notes - Lecture 6: Intertropical Convergence Zone, Jet Stream, Hadley Cell
Document Summary
Tropical trade winds: sub-polar low-pressure cells air in descending part of hadley cell is heated by compression and becomes drier the surface air diverging from the subtropical highs generate earth"s principle surface winds: Winds move away from the polar region in an anti-cyclonic direction producing the polar easterlies. Therefore, the pressure gradient is greater at altitude and winds tend to be stronger. Pressure decreases less rapidly with height in warmer air. Jet streams are narrow, high speed upper level air flows. The jet stream is a river of fast moving air in the upper atmosphere. It steers storms and moves weather patterns across the globe. Jet stream is driven partly by the temperature differential between the arctic and the mid-latitudes. If the temperature differential is large then the jet stream speeds up (zonal flow). If the temperature differential reduces because of a warming arctic then the jet stream weakens (trough/ridge) flow.
