Numerical Study of the Seasonal Variation of Elevated Dust Aerosols from the Taklimakan Desert

Abstract

Mineral dust aerosols from the Taklimakan desert can be elevated to high altitude and transported long distances, thus affecting the Earth's climate. A numerical simulation was conducted to elucidate the seasonal characteristics of dust elevated from the Taklimakan desert. The global land area was divided into the western (including the Taklimakan desert) and eastern region of China and Mongolia (including the Gobi desert), and the other regions so that the relative contributions of mineral dust from the Taklimakan and Gobi deserts to the global dust budget could be identified. The lifetime of the simulated dust aerosols from the Taklimakan desert (2.1 days) was longer than that of aerosols from the Gobi Desert (1.5 days). Simulated dust emission increased in March, peaked in April to May, and decreased from June to September, which is a seasonal variation pattern consistent with the observed Taklimakan dust storm frequency. The simulated Taklimakan dust concentration in the upper troposphere was higher than that of the Gobi dust, suggesting that Taklimakan dust tends to be transported to higher altitudes. It is also suggested that the Taklimakan dust is trapped in the Asian summer anticyclone and partly contributes to the formation of the Asian tropopause aerosol layer during summer.