Impact of soil moisture on dust outbreaks in East Asia: Using satellite and assimilation data

This study is the first assessment of the effects of soil moisture on dust outbreaks using satellite-derived aerosol optical depth (AOD) and global assimilation data on the sand regions across East Asia. The relationships among dust outbreaks, soil moisture, and wind speed were estimated using data sets of the Moderate Resolution Imaging Spectroradiometer and Global Land Data Assimilation System collected over 11 years (2003-2013). The mean AOD exponentially decreased with increasing soil moisture under different wind speed conditions (average determination coefficient = 0.95). As the wind speed conditions became stronger, the probability of a dust outbreak became greatly affected by soil moisture. The threshold soil moisture for dust outbreaks increased with increasing wind speed and decreased with increasing dust-outbreak criteria of AOD. Our results have the capability to be applied to satellite-based dust-outbreak prediction and global-scale dust-emission studies.