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Role of Reemergence in the Central North Pacific Revealed by a Mixed Layer Heat Budget Analysis
Author(s) -
Murata Kazumichi,
Kido Shoichiro,
Tozuka Tomoki
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 - 10.1029/2020gl088194
Subject(s) - advection , mixed layer , climatology , zonal and meridional , entrainment (biomusicology) , geology , sea surface temperature , wind stress , heat flux , ekman transport , pacific decadal oscillation , atmospheric sciences , environmental science , heat transfer , oceanography , upwelling , physics , rhythm , acoustics , thermodynamics
Wintertime sea surface temperature (SST) anomalies that disappear in summer and recur in the following winter are known as “reemergence.” The role of reemergence in recurrent SST anomalies in an area in the central North Pacific is investigated quantitatively for the first time by conducting an online mixed layer heat budget analysis with a realistic ocean model simulation. In contrast to past studies that have emphasized the importance of vertical entrainment of subsurface temperature anomalies, it is shown that several mechanisms are operating in recurrence of SST anomalies during 1977–1999. In particular, anomalous Ekman meridional advection of the mean meridional temperature gradient induced by zonal wind stress anomalies plays an important role in many years. Also, coincidence in the sign of SST anomalies in winter and surface heat flux anomalies in the following autumn leads to recurrence of SST anomalies.