Modeling and Satellite Observation of Dust Emission and Transport over the Taklimakan Desert

Abstract:

Taklimakan Desert is one of the world’s largest deserts and the most intense dust source of Asia. It is located in the Tarim Basin (average elevation: 1.1 km) in northwest China and surrounded by high mountains and plateaus (average elevation over 4.5 km). The Taklimakan Desert is a particularly interesting area not only because a large amount of dust particles is emitted into the atmosphere from this region every year, but also due to the very unique orography and the prevailing wind direction in lower troposphere, dust particles can be lofted above 5 km into upper troposphere. In this study, we found that dust particles from the Taklimakan Desert can be vertically transported to Tibetan Plateau (TP) during spring and summer seasons while suspend within boundary layer in autumn and winter by using multi-year Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations. We investigated the relationship between dust aerosol optical depth (AOD) and surface wind speeds by using multi-angle imaging spectro radiometer (MISR) observations and ERA-Interim data, and further modified the EROD map in the default Weather Research and Forecasting model with chemistry (WRF-Chem) according this relationship in order to ensure realistic simulations of dust emissions. Cases study shown that the simulated dust horizontal and vertical distributions compares well with satellites observations, and dust particles from the Tarim Basin can be blown up to the TP within one day.