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Large scale dynamics and MJO forcing of ENSO variability
Author(s) -
McPhaden Michael J.,
Zhang Xuebin,
Hendon Harry H.,
Wheeler Matthew C.
Publication year - 2006
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 - 10.1029/2006gl026786
Subject(s) - madden–julian oscillation , climatology , anomaly (physics) , forcing (mathematics) , el niño southern oscillation , sea surface temperature , environmental science , multivariate enso index , oscillation (cell signaling) , atmospheric sciences , atmospheric model , la niña , geology , meteorology , oceanography , convection , geography , physics , condensed matter physics , biology , genetics
A simple two‐predictor regression model is developed to estimate the relative influence of large‐scale low frequency ocean‐atmosphere dynamics and high frequency atmospheric forcing on peak sea surface temperature (SST) anomalies associated with El Niño/Southern Oscillation (ENSO) variations for the period 1980–2005. One predictor is equatorial warm water volume (WWV), which is an index for the role that upper ocean heat content plays in regulating ENSO variability. The other predictor characterizes high frequency atmospheric forcing in the western Pacific linked to the Madden‐Julian Oscillation (MJO). The two‐predictor model accounts for about 60–65% of peak Nino3.4 SST anomaly variance at 2–3 season lead times and suggests about equal influence (on average) of low frequency dynamical processes and the MJO on peak ENSO SST anomalies over the past 25 years. The implications of these results for ENSO prediction are discussed.