Model characterization of the South American low-level flow during the 1997-1998 spring-summer season
A relevant feature of the South American low-level circulation during the wet season is a poleward warm and moist current immediately to the east of the Andes often referred to as a low-level jet, because of its resemblance to the Great Plains low-level jet. Provided that the lack of observational d...
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Published in | Climate dynamics Vol. 16; no. 10-11; pp. 867 - 881 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Heidelberg
Springer
01.10.2000
Berlin Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | A relevant feature of the South American low-level circulation during the wet season is a poleward warm and moist current immediately to the east of the Andes often referred to as a low-level jet, because of its resemblance to the Great Plains low-level jet. Provided that the lack of observational data causes a great deal of uncertainty on the ability of analyses to describe diurnal fluctuations of sub-synoptic features like a low-level jet, this description has been carried out using the Eta regional model. Special emphasis has been given to the detection and characterization of a low-level jet (LLJ) east of the Andes, as a feature best developed at night and mesoscale cross-stream dimensions. This study describes the modeled northerly current east of the Andes during the 1997-1998 warm season, and progress on its mean characterization, including diurnal fluctuations and horizontal and vertical structure. From moisture budget calculations a net convergence of moisture flux is found over an area that includes the Del Plata basin, with a maximum southward flux through the northern boundary at low levels. While there are evidences to suggest that this model provides a realistic description of the local circulation, it is emphasized that observational data are needed to gain further understanding of the behavior of the South American low-level jet and its role upon the regional climate. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0930-7575 1432-0894 |
DOI: | 10.1007/s003820000085 |