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| Titel |
Heavy rainfall episodes in Ecuador during El Niño events and associated regional atmospheric circulation and SST patterns |
| VerfasserIn |
A. Bendix, J. Bendix |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7340
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| Digitales Dokument |
URL |
| Erschienen |
In: 1st Alexander von Humboldt International Conference ; Nr. 6 (2006-01-09), S.43-49 |
| Datensatznummer |
250003235
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| Publikation (Nr.) |
 copernicus.org/adgeo-6-43-2006.pdf |
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| Zusammenfassung |
| To date very little is known about the relation between regional circulation
patterns and sea surface temperature development in the Niño 1,2 region
and the occurrence of heavy precipitation in Ecuador and northern Peru. The
current study uses a comprehensive data set of 2544 Meteosat-3 imagery to
investigate the dynamics of heavy precipitation during El Niño in
1991/92. Rainfall maps are retrieved by means of an adjusted version of the
Convective Stratiform Technique (CST) and Cloud Motion Winds (CMW) are
extracted from image sequences by using a special cross-correlation
approach. A spatial factor analysis is applied to extract specific weather
situations with heavy precipitation during El Niño events. The factor
analysis yielded 16 factors. It has been proven that the factor patterns
with the highest variance explanation also occur during the rainy season of
non-El Niño years. However, 6 El Niño-specific situations could be
derived which cause heavy rainfall, especially in coastal Ecuador and
northern Peru. Multi-channel Sea Surface Temperatures (MCSST) and cloud
motion winds are used to describe atmospheric and oceanic dynamics for these
specific weather situations. The analysis shows that high SSTs in
combination with strong SST gradients off the coast and warm SST bubbles
lead to regional differences in moist instability and heavy rainfall. Both
large scale circulation (reversal of the Walker cell) and regional dynamics
(extended land-sea-breeze system) have been proven to contribute to El
Niño rainfall. |
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