Deciphering the Role of Aerosol‐Induced Snow Albedo Feedback on Dust Emission Over the Tibetan Plateau

Abstract

AbstractThe aerosol‐induced snow albedo effect (SAE) and its feedback on the dust emission over the Tibetan Plateau are investigated using the regional climate model (RegCM4.6) coupled with the SNow, ICe, and Aerosol Radiative model. The deposition of absorbing aerosols (black carbon and dust) decreases the albedo of snow over the Himalayan‐Tibetan region, which results in significant surface warming of 1–4 K. This aerosol‐induced surface warming and accelerated snow melting decreased fractional snow cover by 8% and number of snow cover days by 20 days over the region. Compared to the control simulation, this early and more exposure of nonvegetated land resulted in the increase of the dust emission flux by 60% over central Tibet and therefore the columnar dust loading by 10%–40%. This effect alone results in a surface cooling of −4 Wm−2 and also increases the occurrence of dust events by 10%–20%. Therefore, the snow darkening effect due to the deposition of black carbon and dust increases the local emission of dust aerosols, which further increases the aerosol‐induced snow melting and thus perturbs the air quality and radiation balance over the high mountains of Asia.