[MIS09-P05] Wind tunnel experiments for saltation and dust emission under weak crusted Mongolian soil
Keywords:KOSA, Asian dust, dryland, water ratio, PM2.5
This study focuses on the emission process of dust, especially, soil crust effect on the saltation and dust emission. Soil crust is one of the ground surface conditions, which affects dust generation largely due to strong soil aggregation. But it is well not understood how much soil crust effects saltation and dust emission amount yet. To clarify this, wind tunnel experiment was conducted in a laboratory of Forestry and Forest Products Research Institute, Tsukaba, Japan. Toyoura sand is used as saltating grains and Mongol soil which has both finer and larger particles (Loam) sampled at Tsogt-Ovoo in the northern Gobi Desert is used as a target soil. The water ratio is set 0-15 % for making artificial soil crust.
PTV (Particle Tracking Velocimetry) analysis by using a high-speed camera (30000 fps) shows the reduction of kinetic energy of saltation particle after it hits the ground surface. The crusted surface soil was not much erodible under the higher water ratio. Dust concentration decreases under the crusted condition. These findings are fundamental for elucidating the process of dust emission and will link to improve dust forecasting accuracy by atmospheric models.