Decadal heatwave fluctuations in China caused by the Indian and Atlantic Oceans

Abstract

Heatwaves have been more common in China in recent years, largely attributed to human-caused global warming. While ocean variability, notably El Niño–Southern Oscillation (ENSO), influences regional heatwave fluctuations in China, the impact of other oceanic variability remains unclear. Here we show that the tropical Indian Ocean (TIO) and the tropical and subtropical North Atlantic Ocean (TSNAO) significantly modulate the decadal heatwave fluctuations in China. Among them, TIO has the most significant impact on northern China, while TSNAO has a greater impact on eastern China. TIO and TSNAO remotely influence heatwaves in China through abnormal sea surface temperatures (SSTs)-induced changes in atmospheric circulations involving westerlies and Rossby wave trains. Moreover, we demonstrated the physical processes responsible for heatwave fluctuations caused by TIO and TSNAO variability. The heatwave changes were determined jointly by vertical motion-related adiabatic and energy input-related diabatic temperature modifications. Our findings show that, in addition to ENSO, variability in the Indian and Atlantic Oceans is critical for understanding and predicting decadal heatwave changes in China.