A23C-0322
Transport of Dust from the Atmospheric Boundary Layer to the Free Troposphere by a Cold Front: Dust Event in the Gobi Desert on 22-23 May 2013
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Kei Kawai1, Kenji Kai2, Yoshitaka Jin3, Nobuo Sugimoto3 and Dashdondog Batdorj4, (1)Nagoya University, Graduate School of Environmental Studies, Nagoya, Japan, (2)Nagoya University, Nagoya, Japan, (3)National Institute for Environmental Studies, Tsukuba, Japan, (4)National Agency for Meteorology and Environmental Monitoring, Ulaanbaatar, Mongolia
Abstract:
Asian dust is often transported over a long range from the deserts in East Asia to the North Pacific region. The long range transport of the dust has a relationship with the vertical distribution of the dust in the source regions. If the dust reached to the free troposphere, it can be transported over a long range by the westerlies. Therefore, we have conducted a ceilometer observation since May 2013 in the Gobi Desert, which is one of the source regions. On 22-23 May 2013, a dust event occurred in the Gobi Desert as a result of strong wind caused by a developing low pressure system and a cold front. A dust layer was observed near the ground surface by the ceilometer. The maximum top height of the dust layer was 1.8 km above the ground level (AGL). After the cold front passed, a cold air mass advanced, and the dust layer disappeared. The maximum top height of the cold air mass was 1.8 km AGL. The vertical structure of the cold air mass is similar to that of gravity currents. Some dust was transported from the dust layer to the free troposphere by a warm air ascending along the surface of the cold front. This transport is one of the mechanisms that transport dust from the atmospheric boundary layer to the free troposphere, which can cause the long range transport of the dust.
