Modeling study on Inter annual variation of Asian dust storms for recent 25 years with a regional dust transport model

Asian dust particles largely impact on local air quality and the regional or global climate by modifying radiative budget. It is also well known that dust storm activity in East Asia has a strong inter-annual variation. Inter annual variation of dust storm is mainly controlled by the several climatic factors (Asia monsoon/ ENSO). However the mechanism of climatic factors which drive the dust storm is not clearly understood. To clarify the climatic factors affecting the inter annual variation of dust storm, and to evaluate the radiative impact of Asian dust on the atmospheric radiation field, we simulate Asian dust transport over the springtime 25 years with the regional-scale sophisticated dust transport model. This dust model uses a desertification map including the effect of anthropogenic desertification. We will show (1) the detailed validations of the inter annual variation with the long term observations (satellite remote sensing, visibility of surface observation site), and the characteristics of inter annual variation of Asian dust; (2) the result of correlation analysis among climatic indices (ENSO index, intensity index of the Asian polar vortex, Asia monsoon index etc.) and dust activity; and (3) the evaluation of impact of dust aerosol on the atmospheric radiation field over East Asia using the aerosol optical thickness.