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| Titel |
Super El Nino - a synchrony of Indian Ocean Dipole and ENSO dynamics? |
| VerfasserIn |
Saji Hameed, Jin Dachao, Vishnu Thilakan, KyongHee An |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130367
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| Publikation (Nr.) |
 EGU/EGU2016-10614.pdf |
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| Zusammenfassung |
| El Ninos significantly affect societies, economies and ecosystems
on a global scale. The strongest of these events, hereafter super
El Ninos, have disproportionately larger impacts. It is unclear
whether a particular combination of climate states, either internal
or external to the equatorial Pacific, is associated with the unique
spatial and temporal characteristics of these events. This became clear
in the case of the much anticipated 2014 super El Nino - although several
hypothesized precursor climate states were present, the Pacific warming
of 2014 did not develop into a super El Nino. Past studies using statistical
analysis and coupled model experiments have pointed to the possible role of
the Indian Ocean Dipole (IOD) in affecting El Nino. However, no direct
observational evidence for the role of IOD has yet been found. Here we
present for the first time strong and direct observational evidence for the
distinct role of IOD dynamics in modulating El Nino evolution during
co-occurring events. Further, we identify the key process in this interaction
as an atmospheric Kelvin wave dominated downstream circulation forced by
equatorial Indian Ocean convection. We propose that the synchrony of this IOD
forced process with the inherent coupled dynamics in the Pacific associated
with El Nino explains the strong intensity as well as the rapid evolution and
termination of super El Ninos, along with their disproportionate global
impacts. We discuss the implication of our findings for the ongoing El Nino
event which has been projected to rival the 1997 super El Nino in strength
and impacts. |
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