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Modulation of Bjerknes feedback on the decadal variations in ENSO predictability
Author(s) -
Zheng Fei,
Fang XiangHui,
Zhu Jiang,
Yu JinYi,
Li XiChen
Publication year - 2016
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 - 10.1002/2016gl071636
Subject(s) - predictability , climatology , el niño southern oscillation , pacific decadal oscillation , environmental science , sea surface temperature , precipitation , multivariate enso index , madden–julian oscillation , oscillation (cell signaling) , geology , southern oscillation , meteorology , geography , physics , convection , quantum mechanics , biology , genetics
Clear decadal variations exist in the predictability of the El Niño–Southern Oscillation (ENSO), with the most recent decade having the lowest ENSO predictability in the past six decades. The Bjerknes Feedback (BF) intensity, which dominates the development of ENSO, has been proposed to determine ENSO predictability. Here we demonstrate that decadal variations in BF intensity are largely a result of the sensitivity of the zonal winds to the zonal sea level pressure (SLP) gradient in the equatorial Pacific. Furthermore, the results show that during low‐ENSO predictability decades, zonal wind anomalies over the equatorial Pacific are more linked to SLP variations in the off‐equatorial Pacific, which can then transfer this information into surface temperature and precipitation fields through the BF, suggesting a weakening in the ocean‐atmosphere coupling in the tropical Pacific. This result indicates that more attention should be paid to off‐equatorial processes in the prediction of ENSO.