Dust Storms and Long-Range Transport of Dust by Kelvin Waves in East Asia

A detailed study of the role of Kelvin waves in the development of dust storms resulting in the subsequent large-scale transport of dust was performed for three severe dust storm cases that occurred in China and Mongolia on May 3, 2020, March 15, 2021, and March 20, 2023. Observational and numerical model data were analyzed in depth. These data include MODIS satellite images, MERRA reanalysis, surface observations, atmospheric soundings, NAAPS aerosol modeling plots, and WRF simulations. This study found that there were adjustment processes resulting in Kelvin waves in all three cases. The resulting lower tropospheric wind and instability forced by these Kelvin waves caused dust ablation and transport parallel to the Tien Shan, Gobi Altai, and Khangai Mountains. The Kelvin waves developed in association with a cold air mass behind the large-scale cold front that propagated along the periphery of these major mountains. This study demonstrated that the interaction between those mountains and the rapidly changing background atmosphere were the contributing factors for the genesis and propagation of Kelvin waves. These waves caused three dust storms and the subsequent synoptic scale transport of dust impacting East Asia.