Surface sensible heat flux (SHF) over the Tibetan Plateau (TP) plays a crucial role in shaping summertime regional climate and Asian monsoon. This study presents the first high-resolution numerical simulation that directly links the meridional uneven warming mainly over the northern Hemisphere to changes in SHF across the TP. Using the Weather Research and Forecasting (WRF) model sensitivity experiments driven by observed zonal-mean trends in temperature, geopotential height, and winds from 1980 to 2021, we demonstrate that the meridional uneven warming weakens the meridional pressure gradient, inducing an anticyclonic anomaly north of the TP. This anomaly suppresses low-level westerlies over northeastern TP and enhances moisture transport toward the plateau, increasing cloud amount over the TP. The associated radiative effects reduce downwelling shortwave and increase upwelling longwave radiation, lead to a decline in the ground-air temperature difference and, combined with altered winds, produce a robust decrease in SHF over the TP. Ground-air temperature differences primarily drive daytime SHF reductions, especially in the southwest, whereas wind changes amplify the decline in the northeast. Our findings highlight a previously underappreciated pathway through which the meridional uneven warming, especially over the northern midlatitudes, impacts surface energy exchange over the TP. This study has important implications for understanding changes in the Asian monsoon system, regional precipitation patterns, and downstream water resource availability.
Chen et al. (Thu,) studied this question.