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Processes and boreal summer impacts of the 2004 El Niño Modoki: An AGCM study
Author(s) -
Ashok Karumuri,
Iizuka Satoshi,
Rao S. A.,
Saji N. H.,
Lee W.J.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036313
Subject(s) - climatology , sea surface temperature , boreal , tropics , walker circulation , atmosphere (unit) , tropical eastern pacific , environmental science , atmospheric sciences , general circulation model , oceanography , geology , meteorology , pacific ocean , climate change , physics , ecology , biology , paleontology
The sea surface temperature anomalies (SSTA) of tropical Pacific in the boreal summer of 2004 show a distinct tripolar pattern with warm SSTA in the central tropical Pacific, flanked on both sides by cold SSTA. The distinct conditions during the boreal summer of 2004 and the following winter were catalogued as a new coupled phenomenon named El Niño Modoki in a recent generalized study. The 2004 event is unique in the sense that it occurred without any co‐occurring IOD, thereby without any possibility of external modulation of its processes and impacts in the tropics. Using observed data since 1979, we show that the 2004 event indeed involves the distinct equatorial coupled ocean‐atmosphere dynamics different from the conventional El Niño. Further, using an AGCM, we confirm that during boreal summer anomalous twin Walker circulation cells associated with the El Niño Modoki SSTA give rise to observed rainfall anomalies in the tropics.