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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Summertime moisture transport over Southeastern South America and extratropical cyclones behavior during inter-El Nio events

Full text
Author(s):
Mendes da Silva, Gyrlene Aparecida [1] ; Ambrizzi, T. [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Dept Atmospher Sci, Inst Astron Geophys & Atmospher Sci, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: THEORETICAL AND APPLIED CLIMATOLOGY; v. 101, n. 3-4, p. 303-310, AUG 2010.
Web of Science Citations: 3
Abstract

The impact of the inter-El Nio (EN) variability on the moisture availability over Southeastern South America (SESA) is investigated. Also, an automatic tracking scheme was used to analyze the extratropical cyclones properties (system density - SD and central pressure - CP) in this region. During the austral summer period from 1977-2000, the differences for the upper-level wave train anomaly composites seem to determine the rainfall composite differences. In fact, the positive rainfall anomalies over most of the SESA domain during the strong EN events are explained by an upper-level cyclonic center over the tropics and an anticyclonic center over the eastern subtropical area. This pattern seems to contribute to upward vertical motion at 500 hPa and reinforcement of the meridional moisture transport from the equatorial Atlantic Ocean and western Amazon basin to the SESA region. These features may contribute to the positive SD and negative CP anomalies explaining part of the positive rainfall anomalies found there. On the other hand, negative rainfall anomalies are located in the northern part of SESA for the weak EN years when compared to those for the strong events. Also, positive anomalies are found in the southern part, albeit less intense. It was associated with the weakening of the meridional moisture transport from the tropics to the SESA that seems have to contributed with smaller SD and CP anomalies over the most part of subtropics, when compared to the strong EN years. (AU)

FAPESP's process: 05/01804-0 - Influence of the internal variability on the dynamic associated with low-level jet to the east of the Andes and cold fronts during the southern Summer and Winter
Grantee:Gyrlene Aparecida Mendes da Silva
Support Opportunities: Scholarships in Brazil - Doctorate