An assessment of land energy balance over East Asia from multiple lines of evidence and the roles of the Tibet Plateau, aerosols, and clouds

Abstract. With high emissions of aerosols and the known world's “Third Pole” of the Tibet Plateau (TP) in East Asia, knowledge on the energy budget over this region has been widely concerned. This study first attempts to estimate the present-day land energy balance over East Asia by combining
surface and satellite observations as well as the atmospheric reanalysis and Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations.
Compared to the global land budget, a substantially larger fraction of
atmospheric shortwave radiation of 5.2 % is reflected, highly associated with the higher aerosol loadings and more clouds over East Asian land. While a slightly smaller fraction of atmospheric shortwave absorption of 0.6 % is unexpectedly estimated, possibly related to the lower water vapor content effects due to the thinner air over the TP to overcompensate for the aerosol
and cloud effects over East Asian land. The weaker greenhouse effect and
fewer low clouds due to the TP are very likely the causes of the smaller fraction of East Asian land surface downward longwave radiation. Hence, high
aerosol loadings, clouds, and the TP over East Asia play vital roles in the
shortwave budgets, while the TP is responsible for the longwave budgets
during this regional energy budget assessment. The further obtained cloud
radiative effects suggest that the presence of clouds results in a larger
cooling effect on the climate system over East Asian land than that over the globe. This study provides a perspective to understand fully the roles of
potential factors in influencing the different energy budget assessments
over regions.
