Earth Sciences 1022A/B Lecture Notes - Lecture 18: Great Sandy Desert, Kalahari Desert, Arabian Desert
20 Dec 2018
School
Department
Course
Professor
Document Summary
Some of the driest places on earth are near the poles: dry regions constitute ~30% of the earths land surface. Main types of deserts: subtropical, polar, mid-latitude, rainshadow. Steppers semi-arid regions (dry but not quite deserts) If earth"s axis was vertical (relative to orbit) and illuminated uniformly on all point of the equator, then air would circulate in convention cells like this (one cell in each of n and s hemispheres) Key features: warm air rises at the equator (producing a zone of low pressure, cold air sinks towards the poles (producing area of high pressure) Atmospheric circulation on rotating earth: due to earth"s rotation, convection cells are a little more complicated, air flow is deflected due to coriolis force. Northern hemisphere sonoran, sahara, arabian desert, southern hemisphere kalahari. Similar to subtropical deserts, polar deserts occur under high-pressure regions (where dry air flows downwards) Polar deserts near the north pole (e. g. arctic islands) and south pole antarctica)
