Sea Surface Temperature in the South China Sea

Abstract

Interannual variability of the sea surface temperature anomalies (SSTA) over the South China Sea (SCS) is recognized as an index for the Asian monsoon and ENSO system because of its special geographical location for that system.The following results are obtained by the statistical analysis of the observational data.(1) In the northern winter, the SCS SSTA are quite sensitive to the longitudinal shift of global wind anomalies associated with the equatorial Pacific SSTA. This fact is related to that the SCS SSTA and the neighbor SSTA have strong biennial oscillation.(2) When the global wind anomalies are shifted eastward in the winter (BO-type years), the tropical eastern Pacific SSTA tend to change in the following spring. On the other hand, when those wind anomalies are shifted westward (LF-type years), the eastern Pacific SSTA tend to be maintained through the year. The associated differences between the BO and LF-type years are found in the seasonal change of the low-level tropical wind anomalies from the preceding summer through winter.(3) The northern summer SCS SSTA seem to be controlled by in-situ low-level wind anomalies. Furthermore, easterly anomalies over South Asia and the tropical western Pacific and westerly anomalies over East Asia are found in the lower atmosphere for the positive SCS SSTA. It is also shown that the summer SCS SSTA have a statistical relationship with the equatorial central Pacific SSTA in the preceding winter. This fact suggests a relationship between the summer Asian monsoon and the winter phase of ENSO.

Discrepant Effects of Oceanic Advection in the Evolution of SST Anomalies in the South China Sea During El Niño of Different Intensities

“…Abundant water exchange and complex atmospheric processes make the SCS susceptible to the Pacific and Indian Oceans but quite different from them (Liu et al, 2004;Chiang et al, 2018). Observational analyses have shown that the sea surface temperature in the SCS (SCS SST) exhibit abundance of multiple timescales from seasonal to decadal variabilities, which are largely modulated by the East Asian monsoon, El Niño-Southern Oscillation (ENSO), Interdecadal Pacific Oscillation, and global warming (Shen and Lau, 1995;Tomita and Yasunari, 1996;Ose et al, 1997;Chu et al, 1999;Klein et al, 1999;Qu, 2001;Chen et al, 2003;Wang et al, 2006a;Yu and Qu, 2013;Wu et al, 2014;Cheng et al, 2016;Cheng et al, 2017;Cheng et al, 2019;Xiao et al, 2020a;Liang et al, 2021). Among them, the impact of ENSO on the SCS SST on the interannual timescale has been widely studied.…”

Emergence of Future Sea-Level Pressure Patterns in Recent Summertime East Asia

“…The year-to-year correlations of the JRA-55 SLP EOF resolution coefficients with the previous northern winter (December-January-February mean; DJF mean) surface air temperature are shown in Figure 3d-f. The recent year-to-year variations in EOF1-2 exhibit the summer Asian monsoon anomalies after an El Niño winter (e.g., Ose et al 1997;Xie et al 2009), which are specifically warmer SST anomalies in the northern Indian and tropical northern Atlantic oceans (Fig. 3a-b), as well as the high-pressure anomalies to north of the Philippine Islands (Fig.…”

Can Tropical Pacific Winds Enhance the Footprint of the Interdecadal Pacific Oscillation on the Upper-Ocean Heat Content in the South China Sea?

“…Tomita and Yasunari (1996) noticed that the SST in the SCS was closely linked to the SST in the equatorial central Pacific in wintertime. Ose et al (1997) analyzed observational data and found that the close relationship between the warm SST anomalies in summertime in the SCS and warm SST anomalies in the previous wintertime in the equatorial central Pacific may be established through the wind fields. After the 1997/98 super El Niño event, many studies have shown that the ENSO could lead by 5 months and affect the SST in the SCS (Klein et al 1999;Wang et al 2000).…”