Intensification of heatwaves in China in recent decades: Roles of climate modes

Abstract Modes of climate variability can affect weather extremes, posing intractable challenges to our environment. However, what extent modes modulate heatwaves in China under a warming background remains poorly understood. Here, we examine the changes heatwave intensity seven distinct regions: three East, two middle, and west regions over systematically explore impacts modes, by analyzing observations performing model experiments using Bayesian dynamic linear an atmospheric general circulation (AGCM). Abrupt increases are detected across during transition period 1993–2000, intensification robust northern western after trend being removed. The combined El Niño–Southern Oscillation (ENSO), Atlantic Multidecadal (AMO), Indian Ocean Dipole (IOD) explain 62.35–70.01% observed East I, Middle West II regions. Decadal circulations associated with negative phase Interdecadal Pacific (IPO), which is highly correlated decadal ENSO, positive AMO around mid-1990s increase surface air temperature enhance internal modes’ impacts, resulting abrupt past decades. These results highlight importance concurrent transitions regulating heatwaves.