Chemical Evolution of Mineral Dust and Its Impact on Radiative Forcing in East Asia during 2006-2010

Abstract:

Arid regions and deserts in China and Mongolia are two of the main terrestrial sources of airborne dust, with major contribution from Taklamakan and Gobi deserts which can travel to China, Japan, Taiwan and even across Pacific Ocean to US and around north hemisphere. While China has been one of the most rapid-developing countries during the past decade, it also contributes intensive anthropogenic emissions including SO₂ and NOx. Critical uncertainties remain regarding the chemical transformation of dust components during the transport with reactions involving these anthropogenic pollutants, which may significantly alter the optical properties and size distribution of mineral dust, and finally affect regional climate. In this study, we implemented heterogeneous reactions for dust particles into the WRF/CMAQ modeling system, and investigate the chemical evolution of mineral dust during the transport pathway. Integrating the dust-blown scheme of CMAQ, we also probe into the inter-annual changes of dust emission from East Asia, and the radiative forcing changes due to dust particles for 5 consecutive years from 2006-2010.