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Absence of propagating upper ocean heat content anomalies in the eastern tropical South Pacific after ENSO events
Author(s) -
Hasegawa Takuya,
Hanawa Kimio,
Tourre Yves M.,
White Warren B.
Publication year - 2008
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 - 10.1029/2007gl033065
Subject(s) - sea surface temperature , climatology , latent heat , geology , el niño southern oscillation , convection , wind stress , oceanography , upwelling , environmental science , atmospheric sciences , geography , meteorology
In order to explore why after a mature ENSO warm phase (MEWP), upper ocean heat content (OHC) anomalies disappear in the eastern tropical South Pacific (ETSP: 10°S–20°S, 140°W–100°W), relationships with sea surface temperature (SST), sea level pressure (SLP), wind‐stress curl (WSC) and latent heat flux (LHF), are investigated. After a MEWP, positive SST anomalies in the ETSP are first associated with overlying negative SLP anomalies through enhanced atmospheric convection and atmospheric hydrostatic processes. Then negative SLP anomalies and surface winds, lead to positive WSC and negative LHF anomalies (i.e., oceanic heat loss) which dominate the region. The above mechanisms, combined with a weakened South Equatorial Current, contribute to a rapid decay of positive OHC anomalies. It is exactly the opposite of what has been observed in the western tropical North Pacific, where in contrast OHC anomalies associated with ENSO, do grow with time and propagate.