GGR203H1 Lecture Notes - Lecture 2: Polar Easterlies, Hadley Cell, Atmospheric Circulation
Document Summary
Earth has warmed up by 10c in last 100 years. Lake levels were high in western us 18kya, relatively lower but still high in africa. Lakes were high in much of africa, lower in us 6 kya. At this time, sun was closest to earth during northern hemisphere summer, creating stronger monsoons in the summer. Temperature falls in troposphere, increases in stratosphere, falls in mesosphere, increases in thermosphere. Air rises at equator, moves to higher latitudes before descending at pole in one continuous cell. Surface easterlies near equator, westerlies aloft in midlatitudes, surface easterlies near poles. This model is unstable and incorrect based on conservation of angular momentum. Hadley cell: air rises at equator, descends at tropics. Ferrel cell: air descending at tropics and moving north, ascending at mid-latitudes. Polar easterlies, westerlies at midlatitudes, subtropical highs, northeast trades/southeast trades. Wind blows to equator because pressure is lower. One when itcz moving northwards, another when itcz moving back to south.
