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Distinct Growth Rates of the Two ENSO Types
Author(s) -
Ren HongLi,
Wang Run
Publication year - 2020
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 - 10.1029/2020gl088179
Subject(s) - anomaly (physics) , el niño southern oscillation , climatology , sea surface temperature , environmental science , growth rate , oscillation (cell signaling) , geology , atmospheric sciences , physics , mathematics , chemistry , biochemistry , geometry , condensed matter physics
El Niño‐Southern Oscillation (ENSO) events can be grouped into two types based on their sea surface temperature anomaly spatial patterns, that is, eastern Pacific (EP) and central Pacific (CP) types. In this study, we propose a new method to empirically diagnose linear growth rates of the EP and CP ENSO types due to a limitation of applying the traditional Bjerknes stability index method simply to these two types. We spatially project the peak‐time symmetric component of the mixed‐layer oceanic heat budget terms onto the ENSO‐related sea surface temperature anomaly patterns to estimate the ENSO grow rate. After validating the method by comparing it with the Bjerknes stability index, we show that the growth rate is positive for the CP ENSO type and weakly negative for the EP ENSO type, contributed by different feedback terms. The Coupled Model Intercomparison Project Phase 5‐based multimodel ensemble mean shows similar characteristics as the reanalysis for the EP ENSO type rather than the CP ENSO type.