EAS100 Lecture Notes - Lecture 33: Gobi Desert, Orographic Lift, Ferrari 250

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Daniel Alessi

Document Summary

Eas 100 lecture 33 dry weather and introduction to the biosphere. Deserts on earth: one of the manifestations of the global circulation cells, receive less than 250 mm of precipitation per year, difference between desert and drought! Drought indicates deviation from normal amounts of precipitation: can be hot or cold deserts, semiarid land may receive between 250-500 mm, adjacent to deserts themselves. Deserts lie in 4 specific belts (areas of divergence dry air is descending): north polar high, north subtropical high, south subtropical high, south polar high. Desert sediment: not all deserts are just seas of sand, many have rocky desert pavement, wind removes the fine sediment, so only coarser material is left behind! Sand transport when sand is present, turbulent air and wind will form large dunes: remember does take a lot of energy to move small particles, ancient dune sandstones are characterized by large-scale cross-bedding. Adjacent to desert semiarid land: accumulation of wind-blown dust area of deposition, loess.