Open AccessTemporal and spatial variabilities of the South China Sea surface temperature anomaly
Author(s) -
Chu Peter C.,
Lu Shihua,
Chen Yuchun
Publication year - 1997
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 - 10.1029/97jc00982
Subject(s) - empirical orthogonal functions , anomaly (physics) , climatology , sea surface temperature , geology , common spatial pattern , monsoon , spatial ecology , transition zone , ecology , statistics , physics , mathematics , geochemistry , biology , condensed matter physics
In this study we use the National Centers for Environmental Prediction (NCEP) monthly sea surface temperature (SST) fields (1982–1994) to investigate the temporal and spatial variabilities of the South China Sea (SCS) warm/cool anomalies. Three steps of analysis were performed on the data set: ensemble mean , composite analysis to obtain the monthly mean anomaly relative to the ensemble mean , and empirical orthogonal function (EOF) analysis on the residue data relative to . The ensemble mean SST field has a rather weak horizontal gradient: 29°C near the Borneo coast to 25°–26°C near the southeast China coast. Two areas of evident SST anomalies were found in the monthly variation: west of Borneo‐Palawan Islands (WBP) and southeast of the southern Vietnam coast (SVC). Four patterns, monsoon and transition each with two out‐of‐phase structures, were found. During the spring‐to‐summer transition (March to May) the warm anomaly is formed in the northern SCS with located at 112°–119°30′E, 15°–19°30′N. During the fall‐to‐winter transition (October to November) the northern SCS (north of 12°N) cool anomaly is formed in November with located at 108°–115°, 13°–20°N. We performed an EOF analysis on the residue data relative to in order to obtain transient and interannual variations of the SST fields. EOF1 accounts for 47% of the variance and represents the northern SCS warm/cool anomaly pattern. EOF2 accounts for 14% of the variance and represents the southern SCS dipole pattern. Strong northern SCS warm anomaly (1°C warmer) appears during October–November 1987 and January–February 1988, and strong northern SCS cool anomaly (1°C cooler) occurs during March 1986 and November 1992. Furthermore, a strong cross correlation between wind stress curl and SST anomalies, computed from the European Centre for Medium‐Range Weather Forecast analyzed wind stress data and the NCEP SST data for different lags, shows the existence of an air‐sea feedback mechanism in the SCS deep basin.