Characteristics of dust devil and its dust emission in northern margin of the Taklimakan Desert

Dust aerosol has significant impacts on weather, climate, ecology, and global matter cycling, and dust devils are an important source of dust aerosol. The Taklimakan Desert is a major dust source area in East Asia, yet the characteristics of dust devils and their dust emissions are unclear in this region. In this study, the characteristics of dust devils at the northern margin of the Taklimakan Desert were analyzed. Existing equations for estimating dust emission by dust devils were revised based on our observed data, and dust emissions were estimated for the study area. The results showed that dust devils in the study area mainly occurred between March and September, which accounted for 90.9% of the total number of occurrence days in the year. Dust devil occurrence days displayed clear seasonal variation, ranked in the following descending order: summer > spring > autumn > winter. Dust devils tended to occur more frequently during the day, with relatively high occurrences from around 12:00 to 16:00 local standard time (LST) with peak occurrence 14:00-15:00 LST. Of the observed dust devils, 72.5% had a duration of 4 min or less while only 5.9% lasting for more than 6 min. The average annual dust emission from dust devils in the study area was approximately 1.96 t/km(2). The occurrence of dust devils and the calculated amounts of dust emitted were closely related to surface temperature and thermodynamic efficiency.