El Nino signal variability in the precipitation over southeastern South America during austral summer

被引：28

作者：

Silvestri, GE ^{[1
]}

机构：

[1] Consejo Nacl Invest Cient & Tecn, RA-1033 Buenos Aires, DF, Argentina

来源：

GEOPHYSICAL RESEARCH LETTERS | 2004年 / 31卷 / 18期

关键词：

D O I：

10.1029/2004GL020590

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Some aspects of El Nino (EN) events signal in the precipitation over southeastern South America ( SESA) during austral summer are examined. In February - March this signal covers most of the southeast part of SESA and has a wide range of variability in its intensity. The rainiest EN events are characterized by an intensification of the moisture flow from the amazonic forest to SESA jointly with an enhancement of the subtropical jet over South America. The dynamics in upper-levels is associated with a circulation field in the Southern Hemisphere dominated by the presence of the ENSO pattern described in previous studies. During less rainy EN events the moisture flow towards SESA diminishes; and, the structure of the ENSO pattern of circulation over South America implicates a weakening of the subtropical jet. Therefore, the characteristics of the low and upper levels circulation modulate the intensity of the rain over SESA during these events.

引用

页码：L182061 / 5

页数：5