The 3D Evolution of Spatiotemporally Contiguous Summer Heatwaves in China: Tracks and Underlying Mechanism Associated With Compound Typhoons and High‐Pressure Systems

Abstract In the context of global warming, the frequency, intensity, and duration of heatwaves (HWs) are significantly increasing, threatening both human society and natural environment. However, the underlying mechanism of the evolutions of spatiotemporally contiguous summer HWs remains unclear hindering the forecasting of HWs. Therefore, a 3D perspective of HWs was introduced in the present work (i.e., latitude × longitude × time), which can track the horizontal evolution of HWs continuously. Here, our work objectively followed the 3D evolutions of regional summer HWs in China during 1979–2022, and investigated their characteristics, including intensity, duration, and affected area. Among them, the dynamic evolutions of 29 HWs are influenced by compound typhoons and high‐pressure systems. Specifically, the high‐pressure system affects the triggering and maintenance of regional HWs by enhancing the surface heating and subsidence warming, whereas typhoon tracks can modulate the retreat of regional HWs. Westward‐moving typhoons that are influenced by easterly airflows on the southern edge of strong inland high‐pressure systems can force the high‐pressure system to slowly retreat eastward. This interaction results in a long duration and a large affected area of regional HWs. In contrast, northeastward‐moving typhoons quickly cut the weak inland high‐pressure system, and then the fragmented high‐pressure systems in turn promote the northeastward movement of typhoons, leading to the low intensity, short duration, and small affected area of the regional HWs. These findings systematically reveal the interactions between inland high‐pressure systems and typhoon tracks and provide new insights for improving the warning and forecasting skills for the 3D evolution of spatiotemporally contiguous HWs.