Abstract/Summary

The net surface energy flux (Fs) is critical to the Earth’s energy budget and surface processes, but there are still simulation uncertainties at global and regional scales. This study investigates simulated Fs biases and sources over the Asian monsoon region (AMR) in CMIP6 HighResMIP atmospheric models. The global state is investigated first to check if there is any systematic model bias which can affect the AMR as well. In the AMR, the Fs is predominantly upward during winter and downward during summer owing to the seasonal variation in SWs and THF. 95% of the winter Fs bias over the AMR comes from THF, primarily because of the latent heat flux bias. SWs and THF contribute 40–90% and 70–90%, respectively, to the summer Fs bias. The systematic biases of SWs and LWs can be attributed to biases in circulation patterns and cloud cover, whereas biases in THF are influenced primarily by near-surface processes. The high-resolution models perform well in terms of Fs, THF, and the circulation (wind speed at 850 hPa and 10 m) in the low-level troposphere, particularly in winter. The winter multimodel mean error is reduced by 21.5–63.6% in Fs and 25.5–76.7% in THF across the three AMR subregions. Seven out of the nine high-resolution models have higher skill scores for winter Fs and THF than their low-resolution counterparts do in South Asia (SA), with corresponding model numbers of 8 (Fs) and 7 (THF) in East Asia (EA) and the western North Pacific (WNP). This study reveals the advantages of increased horizonal resolution in Fs simulations.