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ENSO amplitude modulation related to Pacific decadal variability
Author(s) -
Imada Y.,
Kimoto M.
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 - 10.1029/2008gl036421
Subject(s) - climatology , pacific decadal oscillation , advection , sea surface temperature , el niño southern oscillation , amplitude , environmental science , modulation (music) , ocean general circulation model , general circulation model , oscillation (cell signaling) , multivariate enso index , atmospheric sciences , geology , climate change , southern oscillation , oceanography , physics , genetics , quantum mechanics , biology , acoustics , thermodynamics
Decadal modulation of El Niño/Southern Oscillation (ENSO) amplitude is reproduced by a long‐term simulation with an atmosphere‐ocean general circulation model. A frequency of the modulation is in phase with Pacific decadal variability (PDV). A detailed analysis of the budget of sea surface temperature (SST) shows that effect of a change in anomalous zonal advection of mean temperature correlated to ENSO development has a dominant role in low‐frequency modulation of ENSO. That is because an equatorial zonal SST gradient changes periodically in the PDV cycle as a change in the background mean state for ENSO. Such characteristics are consistent with an observed climate shift and changes in ENSO characteristics that occurred in mid‐1970s.