Open AccessSea surface temperature cooling mode in the Pacific cold tongue
Author(s) -
Zhang Wenjun,
Li Jianping,
Zhao Xia
Publication year - 2010
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jc006501
Subject(s) - sea surface temperature , climatology , empirical orthogonal functions , pacific decadal oscillation , environmental science , mode (computer interface) , forcing (mathematics) , data assimilation , climate model , global warming , atmospheric model , climate change , geology , oceanography , meteorology , geography , computer science , operating system
Long‐term variability in sea surface temperature (SST) in the equatorial Pacific and its relationship with global warming were investigated using three SST data sets (Hadley Center Global Sea Ice and Sea Surface Temperature, extended reconstruction sea surface temperature, and Kaplan), atmospheric fields from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis, and subsurface sea temperature from the Simple Ocean Data Assimilation data set. A cooling mode in the equatorial Pacific cold tongue is evident in all three SST data sets for two periods: 1870–2007 and 1948–2007. This cooling, which is indicated by the second empirical orthogonal function mode, is characterized by cooling in the Pacific cold tongue and warming elsewhere in the tropical Pacific. Its principal component time series is highly correlated with global mean surface temperature combining air temperature and SST. In association with the SST cooling mode, atmospheric fields and subsurface sea temperature are coupled in the tropical Pacific during recent decades. Moreover, for the coupled models in the 20th century run (20C3M), obtained from the Intergovernmental Panel on Climate Change Fourth Assessment Report database, those with realistic features of El Niño‐Southern Oscillation (ENSO) events can well show the cooling mode. However, the cooling mode is not shown in these coupled models in a preindustrial scenario with no forcing attributed to global warming. Results from observations and models suggest that the cooling mode is very likely caused by global warming. This conclusion is supported by a hypothesis that considers dynamic effects in the equatorial Pacific Ocean in response to global warming.