Impact of the tibetan plateau heat source on heatwaves in China

Known as the “Third Pole”, the Tibetan Plateau (TP) profoundly influences the regional and global weather and climate. This study investigates the relationship between the atmospheric heat source (AHS) over the TP and heatwaves in China, and estimates future variations. The results show that heatwaves during the summers of 1979–2014 predominantly occurred in Northwest China and Eastern China with increasing rates of 0.24 and 0.09 day yr^− 1, respectively, accompanied by a strengthening AHS over the TP, with an increase reaching 2.5 W m^− 2 yr^− 1. Heatwave days in Eastern China decrease by 63.44%, and the average temperature of heatwaves decreases by 1.2 °C after setting the vertical diabatic heating to zero in Eurasia, where the topography is over 500 m in the TIP-nosh experiment from Coupled Model Intercomparison Project Phase 6 (CMIP6), which causes the AHS over the TP to decrease by 136.62%. The AHS over the TP causes anomalous anticyclones northeast of the TP, subsequently influencing heatwaves in Eastern China. Under the Shared Socioeconomic Pathways (SSPs) scenarios of SSP1-2.6, SSP2-4.5, and SSP5-8.5 in 2015–2100, the relationship between the AHS over the TP and the heatwave days in China during summer will become closer. The AHS over the TP increases by 4.75%, 7.63%, and 11.70%, respectively, accompanying with more increases in heatwave days in Eastern China and higher increases in the average temperatures of heatwaves in Northwest China. The close relationship between the AHS over the TP and heatwaves in China provides valuable clues for projecting future changes in heatwaves.