A dust event in the Mongolian Gobi Desert in spring 2016: Observations and vertical dust flux estimation

摘要

A meteorological and dust monitoring tower with 20 m height set up at a Nomgon site in the Mongolian Gobi Deserts in 2010. The Nomgon monitoring tower equipped with wind speed sensors at 2, 4, 10 and 20 m height above the ground level (AGL), a wind direction sensor at 10 m height, a sonic anemometer to measure turbulent momentum flux at 8 m height and a soil moisture sensor at 5 cm depth. A dust storm was expected in the Mongolian Gobi from 30 April to 1 May 2016 and two aerosol monitors (Dust-Trak) were set at 0.9 and 2.95 m heights in the tower for measuring PM_(10). Above mentioned data from the tower during an intensive observation period (IOP) of the dust event are used in this study. In association with a surface cyclone, its frontal system and a trough aloft, dust concentrations of PM_(10)increased during the dust storm period due to raised wind speed in the dry conditions of air and soil. The present study aims to estimate friction velocity (u_(*)) and vertical dust flux (F) around the Nomgon site during the dust storm period. The observations and estimation results are presented.