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Bendix, J.; Trachte, K.; Palacios, E.W.; Rollenbeck, R.; G&ouml;ttlicher, D.; Nauss, T. &amp; Bendix, A. (2011): <b>El Ni&ntilde;o meets La Ni&ntilde;a - anomalous rainfall patterns in the &quot;traditional&quot; El Ni&ntilde;o region of southern Ecuador </b>. <i>Erdkunde</i> <b>65</b>, 151-167.

Resource Description

Title: El Niño meets La Niña - anomalous rainfall patterns in the "traditional" El Niño region of southern Ecuador
FOR816dw ID: 990
Publication Date: 2011-07-04
License and Usage Rights:
Resource Owner(s):
Individual: Jörg Bendix
Contact:
Individual: Katja Trachte
Contact:
Individual: Enrique Wilson Palacios
Contact:
Individual: Ruetger Rollenbeck
Contact:
Individual: Dietrich Göttlicher
Contact:
Individual: Thomas Nauss
Contact:
Individual: Astrid Bendix
Contact:
Abstract:
In this paper, the central Pacific cold event of 2008 and its exceptionally warm conditions in the eastern tropical <br/> Pacific are analyzed by using rainfall data of south Ecuadorian meteorological stations, sea surface temperatures in the El <br/> Niño3 and 1+2 regions, and simulations with the Weather Research and Forecasting (WRF) model. It can be shown that El <br/> Niño-like rainfall conditions with severe inundations occur particularly in the coastal plains of southern Ecuador while a <br/> central Pacific cold event prevails. In contrary to previous situations, positive rainfall anomalies as a result of El Niño-like <br/> conditions in the El Niño1+2 region during the 2008 La Niña event occurred in both regions, the coastal plains and the <br/> highlands, for the first time. A detailed analysis of the ocean-atmosphere system during episodes of heavy rainfall reveals <br/> typical El Niño circulation and rainfall patterns as observed during previous El Niño events for the coastal area and La <br/> Niña-like conditions for the highlands. The spreading of Pacific instability in the Niño1+2 region to the eastern escarpment <br/> of the Andes could be the result of a temporary eastward shift of the Walker circulation. The unusual combination of El <br/> Niño-like conditions in the eastern tropical Pacific during a La Niña state in the central Pacific is the newest indicator for <br/> an impact mode shift regarding severe rainfall anomalies during El Niño/La Niña events in the traditional El Niño area <br/> of southern Ecuador since the end of the last century. Since 2000, El Niño events unexpectedly provide below average <br/> rainfall while central Pacific La Niña conditions generate exceptional severe flooding in the normally drier coastal plains. <br/> The novel sea surface temperature (SST) anomaly dipole structure between the eastern and central/western tropical Pacific <br/> and the weakening of El Niño events since 2000 could be due to natural decadal oscillations in the El Niño background <br/> state, the Pacific Decadal Oscillation (PDO). However, the observed atmospheric patterns and the recent increase of the <br/> SST anomaly difference between the central and the eastern tropical Pacific resemble structures that also result from climate <br/> change simulations.
Keywords:
| South Ecuador | el nino | la nina | ENSO | rainfall anomalies | sea surface temperature anomalies |
Literature type specific fields:
ARTICLE
Journal: Erdkunde
Volume: 65
Page Range: 151-167
ISSN: 0014-0015
Metadata Provider:
Individual: Bernhard Runzheimer
Contact:
Online Distribution:
Download File: http://www.lcrs.de/publications.do?citid=990


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