GGR214H5 Lecture Notes - Lecture 12: Polar Easterlies, Coriolis Force, Westerlies
Document Summary
Produces subtropical high at roughly 30 degrees celsius: rising air in the itcz produces consistent precipitation. Tropical rainforests: sinking air in the subtropics produces clear skies with little rain. Sub-tropical deserts: equatorward flow at the surface produces trade wind easterlies. Frequently disrupted by mid-latitude cyclones and anti-cyclones: swirling winds around a central pressure system, cyclones are the main source of mid-latitude precipitation. Cold air at the poles causes surface highs: very low precipitation: air is pushed toward mid-latitudes: causes polar easterlies, the boundary between cold polar air and warm subtropical air is the polar front. Interaction between warm and cold air leads to polar low and mid-latitude cyclone development. The jet streams: each hemisphere, ~2 major jet streams (they can split, meander, high altitude, fast moving, westerly winds 150 km/h (average, maximum strength between 300 and 200 hpa pressure surfaces. Band ranging from 150-500 km wide, few km"s deep, average wind speeds 80.
