Investigation of the dust reservoir effect of the Tarim Basin using WRF-GOCART model

The Taklamakan and Gobi Deserts are two important dust source regions which are located in northwestern China where the topography is complicated. In this study, a historical severe dust episode was reconstructed and the subsequent dust behavior influenced by the topography was investigated by using the Weather Research and Forecasting (WRF) model coupled with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. Based on the validated simulation results and model sensitivity trials, the study suggest that the topography of the Tarim Basin can function as a dust reservoir, which indicates that the basin can trap the ground-released dust at the beginning, and then re-release the trapped dust at a later time as a secondary source if the meteorological conditions permit. Moreover, to evaluate the dust reservoir effect of the Tarim Basin on the adjacent area, the mass concentration of PM10 was measured during the dust episode in a downwind city. Overall, given the dust modeling and PM10 sampling, the results indicate that the dust reservoir cannot only re-release dust aerosol as a secondary source, but also, the existence of a dust reservoir can prolong and exacerbate the impact on the air quality of the adjacent area.