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A Concise and Effective Expression Relating Subsurface Temperature to the Thermocline in the Equatorial Pacific
Author(s) -
Yuan Xinyi,
Jin FeiFei,
Zhang Wenjun
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 - 10.1029/2020gl087848
Subject(s) - thermocline , sea surface temperature , climatology , el niño southern oscillation , geology , oscillation (cell signaling) , pacific decadal oscillation , hyperbolic function , subsurface flow , environmental science , geophysics , mathematics , chemistry , mathematical analysis , biochemistry , geotechnical engineering , groundwater
The temperature of the subsurface water entrained into the surface mixed layer plays a key role in controlling the sea surface temperature (SST) and its interannual variability in the equatorial Pacific. In this paper, we combine a hyperbolic tangent function bounded by the warm pool SST and centered at the thermocline depth with a variable sharpness parameter to describe the time‐space evolutions of the subsurface temperature. Under simple approximations of the sharpness parameter, this concise expression becomes remarkably efficient in capturing the observed and climate‐model simulated subsurface temperature variability in terms of anomalies of the thermocline depth and SST of the El Niño‐Southern Oscillation (ENSO) phenomenon. The formulations for the subsurface temperature and thermocline sharpness developed in this work should be useful tools for evaluating and understanding the role of the thermocline feedback in ENSO behaviors in both theoretical and comprehensive climate models.