The role of the Maritime Continent SST anomalies in maintaining the Pacific–Japan pattern on decadal time scales
The role of the Maritime Continent SST anomalies in maintaining the Pacific–Japan pattern on decadal time scales
复制标题
海洋大陆海温异常在十年时间尺度上维持太平洋-日本格局中的作用
DOI：
10.1175/jcli-d-21-0555.1
复制
发表时间：
2021-11
影响因子：
4.9
通讯作者：
Sheng Chen
中科院分区：
文献类型：
--
作者：
Mingmei Xie;Chunzai Wang;Sheng Chen
Abstract The decadal Pacific–Japan (PJ) pattern, the dominant decadal mode of summer vorticity anomaly over East Asia, is characterized as a meridionally arranged wave pattern with one anomalous cyclone located over Taiwan, and two anomalous anticyclones around the South China Sea (SCS) and the Bohai Sea. This pattern can cause wetter and colder conditions in Southeast China and dryer and warmer conditions in North China. Local SST–rainfall relationship reveals that the Maritime Continent (MC) SST can act as an engine to regulate and maintain the decadal PJ pattern. Driven by enhanced convection over the MC, anomalous divergent flows in the upper troposphere move northward, cross the equator and then converge and subside over the SCS. The SCS low-level divergence, maintained by this meridional overturning circulation under the Sverdrup vorticity balance, further works as a Rossby wave source and excites the decadal PJ pattern pointing straight northward. The transhemispheric impacts of the MC SST are well reproduced by both the atmospheric general circulation model and the dry linear baroclinic model, with the former emphasizing the MC’s original forcing role and the latter highlighting the SCS anticyclone’s role in relaying and amplifying those climatic impacts. Thus, our results indicate that SST variations over the MC region can be viewed as a potential source of East Asian decadal climate predictability.
