16:00 〜 16:15
[MIS09-08] Occurrence of micro-meso scale dust storms and its relationship to the vegetation and topography in Mongolian grassland and Gobi Desert
キーワード：アジアダスト、ひまわり8号DustRGB、ダストストームのホットスポット
Gobi Desert and Mongolian grassland are one of the main sources of the Asian dust. In order to investigate the occurrence of micro-meso scale dust storms and its relationship to the vegetation and topography, we conducted moving observations running across the Gobi Desert from Ulaanbaatar to Dalanzadgad in springs of 2015-2017. An optical particle counter (OPC: Aerotrak 9306-V2), a sunphotometer (Microtops II) and meteorological instrument were installed in a car.
The vegetation had a suppression effect on the dust emission. Number concentrations of coarse particles (1-10μm) decreased from the desert to the grassland. They had significant negative correlations with the vegetation (NDVI) from 3μm to 10μm, but the number concentration at 0.3 – 0.5 μm had little correlation to the vegetation.
During the moving observations, we found a hotspot of dust storms in the Gobi Desert. An analysis of Himawari-8 Dust RGB clearly shows that the hotspot appeared at a jointing point of two valleys, a bottleneck and an exit of a valley.
In summary, the horizontal distribution of number concentrations of aerosol particles reflected the surface vegetation. Locations of the hotspot were determined by a local topography such a jointing point of two valleys.
The vegetation had a suppression effect on the dust emission. Number concentrations of coarse particles (1-10μm) decreased from the desert to the grassland. They had significant negative correlations with the vegetation (NDVI) from 3μm to 10μm, but the number concentration at 0.3 – 0.5 μm had little correlation to the vegetation.
During the moving observations, we found a hotspot of dust storms in the Gobi Desert. An analysis of Himawari-8 Dust RGB clearly shows that the hotspot appeared at a jointing point of two valleys, a bottleneck and an exit of a valley.
In summary, the horizontal distribution of number concentrations of aerosol particles reflected the surface vegetation. Locations of the hotspot were determined by a local topography such a jointing point of two valleys.