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contributor authorLenters, J. D.
contributor authorCook, K. H.
date accessioned2017-06-09T14:34:22Z
date available2017-06-09T14:34:22Z
date copyright1997/03/01
date issued1997
identifier issn0022-4928
identifier otherams-21943.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4158338
description abstractThe climatological structure in the upper-tropospheric summertime circulation over South America is diagnosed using a GCM (with and without South American topography), a linear model, and observational data. Emphasis is placed on understanding the origin of observed features such as the Bolivian high and the accompanying ?Nordeste low? to the east. Results from the linear model indicate that these two features are generated in response to precipitation over the Amazon basin, central Andes, and South Atlantic convergence zone, with African precipitation also playing a crucial role in the formation of the Nordeste low. The direct mechanical and sensible heating effects of the Andes are minimal, acting only to induce a weak lee trough in midlatitudes and a shallow monsoonal circulation over the central Andes. In the GCM, the effects of the Andes include a strengthening of the Bolivian high and northward shift of the Nordeste low, primarily through changes in the precipitation field. The position of the Bolivian high is primarily determined by Amazonian precipitation and is little affected by the removal of the Andes. Strong subsidence to the west of the high is found to be important for the maintenance of the high?s warm core, while large-scale convective overshooting to the east is responsible for a layer of cold air above the high.
publisherAmerican Meteorological Society
titleOn the Origin of the Bolivian High and Related Circulation Features of the South American Climate
typeJournal Paper
journal volume54
journal issue5
journal titleJournal of the Atmospheric Sciences
identifier doi10.1175/1520-0469(1997)054<0656:OTOOTB>2.0.CO;2
journal fristpage656
journal lastpage678
treeJournal of the Atmospheric Sciences:;1997:;Volume( 054 ):;issue: 005
contenttypeFulltext


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