Study on the Asian dust emitted from the hotspot in the Gobi Desert

Abstract

We have studied the Asian dust emitted from a hotspot in the Gobi Desert by a lidar network, analyses of Himawari-8 Dust RGB and meteorological fields, and a field survey since 2013. We found a remarkable dust hotspot in the Gobi Desert by the filed survey and analysis. The Himawari-8 Dust RGB imagery shows that the dust storm occurred in an orographic convergence zone sandwiched between the Khangai, Altai, and Gurvan Saikhan Mountains in the Gobi Desert. The lidar network operating in Dalanzadgad, Sainshand, and Zamyn-Uud, Mongolia shows a dust layer development over the Gobi Desert in association with a cold frontal system and the long-range transport of the dust. We estimated the massextinction conversion factor MECF (g m-2) from simultaneous observations using an optical particle counter (OPC) installed on a tethered balloon and a ceilometer in the Gobi Desert. The MECF values decreased from the Asian dust source (Dalanzadgad 1.91 g m-2) to the lee-side areas (e.g., Tsukuba 1.18 g m-2) due to the gravitational settling of large dust particles.