Impacts of Surface Sensible Heating Over the Tibetan Plateau on Cloud Fraction and Surface Radiation Budget in Surrounding Asia

The Tibetan Plateau (TP) surface heating profoundly regulates the Asian circulation, but its roles in regional clouds and surface radiation budget remain unclear. Here, we investigate the impacts of the TP surface sensible heating on the surrounding Asian cloud fraction and surface radiation budget using numerical climate experiments that vary sensible heat exchange. The TP surface sensible heating, as an elevated heating source, can induce a low-level cyclone surrounding the TP and ascent over the central-eastern TP, pumping air into the middle troposphere. Consequently, spring cloud fractions significantly increase over the east TP and East China (EC) owing to the TP surface heating, enhancing cloud radiative effects and longwave radiation but reducing shortwave and net radiation at the surface, whereas the opposite changes occur over the west TP. The summer TP impacts exhibit more substantial changes in both magnitude and spatial coverage relative to spring states. Due to the coupling between the upper and lower circulations forced by the TP surface heating, increased cloud fractions extend over the whole TP in summer, with enhanced ascent and cloud radiative cooling dominated by the shortwave component. Meanwhile, cloud fractions decrease over Central and North Asia, accompanied by abnormal descent, weakened cloud radiative cooling, and minimal change in net surface radiation due to a weak offset between longwave and shortwave radiations. Our results indicate that the TP surface sensible heating significantly influences the distribution and magnitude of the surrounding Asian cloud fraction and surface radiation budget via circulation responses.