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Multidecadal modulation of El Niño–Southern Oscillation (ENSO) variance by Atlantic Ocean sea surface temperatures
Author(s) -
Dong Buwen,
Sutton Rowan T.,
Scaife Adam A.
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 - 10.1029/2006gl025766
Subject(s) - thermocline , atlantic multidecadal oscillation , climatology , el niño southern oscillation , pacific decadal oscillation , sea surface temperature , atlantic equatorial mode , multivariate enso index , tropical atlantic , oceanography , ocean heat content , stratification (seeds) , environmental science , geology , la niña , seed dormancy , botany , germination , dormancy , biology
Observations suggest a possible link between the Atlantic Multidecadal Oscillation (AMO) and El Niño–Southern Oscillation (ENSO) variability, with the warm AMO phase being related to weaker ENSO variability. A coupled ocean‐atmosphere model is used to investigate this relationship and to elucidate mechanisms responsible for it. Anomalous sea surface temperatures (SSTs) associated with the positive AMO lead to change in the basic state in the tropical Pacific Ocean. This basic state change is associated with a deepened thermocline and reduced vertical stratification of the equatorial Pacific ocean, which in turn leads to weakened ENSO variability. We suggest a role for an atmospheric bridge that rapidly conveys the influence of the Atlantic Ocean to the tropical Pacific. The results suggest a non‐local mechanism for changes in ENSO statistics and imply that anomalous Atlantic ocean SSTs can modulate both mean climate and climate variability over the Pacific.