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| Titel |
Differentiating flavors of positive IOD events in recent decades |
| VerfasserIn |
Evan Weller, Wenju Cai, Yan Du, Seung-Ki Min |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250103728
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| Publikation (Nr.) |
 EGU/EGU2015-3139.pdf |
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| Zusammenfassung |
| Phase locked to austral winter and spring, canonical positive Indian Ocean Dipoles (pIODs)
generally peak in spring. In recent decades, there has been an increase in unseasonable pIODs
which, different from canonical pIODs, peak and decay by September. Distinguishing
unseasonable pIODs from canonical pIODs is important, as conditions leading to more
frequent unseasonable events are projected to persist in a warming climate. Here using
superimposition of the ?rst two seasonally evolving dominant modes of tropical Indian Ocean
rainfall variability, we differentiate these types of pIODs. The ?rst mode re?ects
characteristics of canonical pIODs, in which anomalies intensify with seasonal evolution.
However, the second mode, with cool and dry anomalies extending from the eastern pole,
reverses from winter to spring, signifying the demise of unseasonable pIODs. Processes
embedded in the second mode re?ect timing of propagation in equatorial Kelvin
waves and their relative importance to the ?rst mode, in generating different pIODs. |
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