Interdecadal difference of interannual variability characteristics of SCS SST associated with ENSO
Title: Interdecadal difference of interannual variability characteristics of SCS SST associated with ENSO
Journal: Journal of Climate, 28: 7145-7160
Authors: YANG Y. -L., S. -P. Xie, Y. Du*, and H. Tokinaga
Abstract:The correlation between sea surface temperature (SST) and El Niño–Southern Oscillation (ENSO) persistsinto post-ENSO September over the South China Sea (SCS), the longest correlation in the World Ocean. Slowmodulations of this correlation are analyzed by using the International Comprehensive Ocean-AtmosphereDataset (ICOADS). ENSO’s influence on SCS SST has experienced significant interdecadal changes over thepast 138 years (1870–2007), with a double-peak structure correlation after the 1960s compared to a single-peakbefore the 1940s. According to the ENSO correlation character, the analysis period is divided into four epochs.In epoch 3, 1960–83, the SST warming and enhanced precipitation over the southeastern tropical Indian Ocean,rather than the Indian Ocean basinwide warming, induce easterly wind anomalies and warm up the SCS in thesummer following El Niño. Besides the Indian Ocean effect, during epochs 2 (1930-40) and 4 (1984-2007), thePacific-Japan (PJ) pattern of atmospheric circulation anomalies helps sustain the SCS SST warming throughsummer (June-August) with easterly wind anomalies. The associated increase in shortwave radiation and decreasein upward latent heat flux cause the SCS SST warming to persist into the summer. Meanwhile, the rainfallresponse around the SCS to ENSO shows interdecadal variability, with stronger variability after the 1980s. Theresults suggest that both the remote forcing from the tropical Indian Ocean and the PJ pattern are important forthe ENSO teleconnection to the SCS and its interdecadal modulations.