Characteristics of High Temperature Circulation in China of the Summer 2022 and Their Relationship with Tropical Sea Surface Temperature Anomalies

Intraseasonal circulation characteristics in the summer of 2022 and the influences from tropical oceans were studied by using the NCEP/DOE monthly reanalysis data and NOAA observational datasets during 1979–2022 with the composite and correlation analysis methods. The results show that there are significant spatial variations in temperatures in Central and Eastern China, the center of high temperature anomalies located in Central China, Southwest China, and the entire Yangtze River Basin in June, July, and August, respectively. The simultaneously strengthened Western Pacific Subtropical High (WPSH) and South Asian High (SAH), as well as their overlap, ultimately formed a rare Northern Hemisphere subtropical high, which is the direct cause of the high temperature in Central and Eastern China in the summer of 2022. However, the East Asian summer circulation in 2022 is distinct from a classic response to La Niña. The weak convection anomalies in the South China Sea and east of the Philippines and the insignificant East Asia–Pacific teleconnection pattern are both different from the typical La Niña years. The tropical Sea Surface Temperature (SST) anomalies in the summer of 2022 contributed to the formation of these extreme high temperature processes. The cold SST anomalies in the tropical West Indian Ocean and tropical Central Pacific Ocean are conducive to the occurrence of high temperatures in the Yangtze River Basin and Central China, respectively. The cold SST anomalies in the tropical West Indian Ocean contribute to the strengthening of the SAH, whereas the cold SST anomalies in the tropical Central Pacific Ocean may be an important cause of the strengthened WPSH.