Radiative forcing and temperature response of dust aerosols over East Asia in the latest decade

A regional climate model,RegCM3,coupled with an online dust module,is used to simulate the radiative forcing(RF) and temperature response of dust aerosols over East Asia in the latest decade(2000-2009).The simulation results show that the geographical and seasonal differences of dust aerosols distribution over East Asia are obvious.There exist two extremes of dust aerosols with column burden(CB) greater than 1,000 mg/m 2 ;one is in the Taklimakan Desert of the Xinjiang Uigur Autonomous Region,China,and the other is in the Badain Jaran Desert of the Inner Mongolian Autonomous Region,China.The maximum value of CB appears in spring,the secondary maximum in winter,and the minimum in autumn.The RF of dust aerosols has distribution characteristics similar to CB.The regional averaged RF over East Asia at the top of atmosphere(TOARF) is 1.72 W/m2 in spring and 1.17 W/m2 in autumn,and that at the surface(SURRF) is 4.34 W/m2 in spring and 2.33 W/m2 in autumn.The temperature at the surface is decreased by dust aerosols;the regional averaged temperature decrease over East Asia is 0.154 °C in spring and 0.085 °C in autumn.There are different impacts of dust aerosols on air temperature at different heights.The air temperature is decreased by dust aerosols in the lower troposphere,but the extent of the decrease diminishes with increasing height.The air temperature is in fact increased by dust aerosols at the height of 300-400 hPa in spring,which is greatly different from that in autumn.