Long-term Variation of Dust Devils in East Asia during 1959-2021

Abstract

Dust devils play an important role in dust transport by carrying it from surface into the atmosphere, especially in summer. However, information on how dust devil changed in the past decades and what caused these changes remains lacking. Based on thermodynamic criterion and ERA5 reanalysis dataset, this study investigated long-term variation of dust devil in East Asia over the past 60 years. We found the annual mean frequency of dust devil in East Asia was approximately 8.2×10 5 hours for 1959 to 2021. In particular, it is shown that an overall downward trend in dust devil frequency over the study period in East Asia, among which strong dust devils declined significantly at the fastest rate while the weak ones dropped insignificantly. Moreover, dust devil frequency in the Gobi Desert (GD) increased obviously but they decreased in the Taklimakan Desert (TD). It is represented that there was a peak for monthly variation of dust devil, shifting from June to July, over the past decades. For the diurnal changes, dust devils mainly occurred between 10:00 and 16:00 at Local Time (LT), with over 60% of them happening between 12:00 LT and 14:00 LT. We also found a negative correlation between precipitation and dust devil frequency. This study provides a comprehensive understanding of dust devils in East Asia over the past decades, which is of great importance to further evaluate its impact on climate, environment as well as ecosystem.