Impact of long-range desert dust transport on coastal East Asia: analysis of urban dust concentration and wet deposition with model simulation

Abstract

Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model simulations for dust in 2007 are applied in this study to investigate the impact of long-range desert dust transport on the dust concentration and wet deposition in coastal cities of East Asia: Shanghai and Hong Kong. The temporal variation of dust concentrations in both Shanghai and Hong Kong exhibits a maximum in spring (May), with a majority of Gobi dust, which accounts for 88 % in Shanghai and 58 % in Hong Kong in the lower troposphere. Correspondingly, the peaks of convective and large-scale wet deposition in May in Shanghai are controlled by Gobi dust, with a contribution of 74–83 %. The wet deposition of dust in summer is affected mainly by strong convective precipitation and dominated by Taklamakan dust, with a contribution of 31–47 % in Shanghai and 19–37 % in Hong Kong, followed by Arabian and Karakum–Kavir dusts. The wet deposition in spring (April) is caused mainly by large-scale precipitation, with a majority of Gobi dust, which accounts for 57 % in Shanghai and 71 % in Hong Kong, followed by Sahara and Taklamakan dusts. The temporal variation of wet deposition of dust in Shanghai is affected mainly by the dust concentration, while the variation in Hong Kong is controlled by both dust concentration and convective precipitation.