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Extratropical forcing of El Niño–Southern Oscillation asymmetry
Author(s) -
Anderson Bruce T.,
Furtado Jason C.,
Cobb Kim M.,
Di Lorenzo Emanuele
Publication year - 2013
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 - 10.1002/grl.50951
Subject(s) - extratropical cyclone , climatology , forcing (mathematics) , atmospheric circulation , environmental science , sea surface temperature , el niño southern oscillation , boreal , atmospheric sciences , geology , paleontology
Boreal winter near‐surface atmospheric circulations over the Hawaiian region are known to influence the state of the tropical Pacific and initiate the development of El Niño–Southern Oscillation (ENSO) events. Here we show that these same preceding near‐surface circulations have an additional influence on the longitudinal position of the resultant ENSO‐related sea surface temperatures (SSTs) as well, with warm (cold) events systematically shifted to the east (west) of the typical SST anomalies. In influencing this positioning, these atmospheric circulations in turn modify the near‐ and far‐field climate responses to these SSTs such that during warm events, the typical ENSO‐related responses east (west) of the dateline are generally enhanced (reduced); conversely, during cold events, the typical ENSO‐related responses are generally reduced (enhanced). The fact that the extratropical atmospheric circulations in question influence the asymmetry of ENSO extremes with a 12 month lead time carries important implications for predicting the socioeconomic impacts of these events.