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| Titel |
Extratropical SST: a key to understand the discrepancy in future Sahel rainfall projections |
| VerfasserIn |
Jong-Yeon Park, Jürgen Bader, Daniela Matei |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250100371
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| Publikation (Nr.) |
 EGU/EGU2014-16322.pdf |
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| Zusammenfassung |
| Future development of Sahel rainfall is highly uncertain. Previous results of Coupled Model Intercomparison Project Phase 3 (CMIP3) show opposite rainfall trends among different coupled general circulation models (GCMs). The twenty-century cross-model consensus in linking Sahel rainfall to certain tropical sea-surface temperature (SST) patterns breaks down for the twenty-first century. Such uncertainties have not been improved even in a new generation of GCMs, i.e. CMIP5. Here we found, for the first time, that different amplitudes of future extratropical SST warming could be a crucial driver for the discrepancy in the projected Sahel rainfall. The relationship between SST and Sahel rainfall that holds for the twenty-century can persist into the twenty-first century when the extratropical SSTs are taken into account. A suite of SST-sensitivity experiments with an atmospheric GCM confirms that strong extratropical warming induces a significant increase in Sahel rainfall, while warming in the tropics reduces rainfall. This result suggests an emerging role of extratropical SST in a trustworthy projection of future Sahel rainfall. |
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