Improvement of dust emission parameterization scheme for dust devils based on intensive observations in the northern margin of the Taklimakan Desert

We aimed to improve and evaluate the dust devil parameterization scheme using intensive observations of meteorological and dust devil data in the desert-oasis ecotone of the Xiaotang region in the northern margin of the Taklimakan Desert in combination with GPS sounding in the hinterland of the desert. The results indicated that the temperature difference between the surface and air at a height of 2 m above the ground suitable for dust devil formation was 16 & DEG;C. In addition, the suitable wind speed (2 m height above ground surface) was 3.2-3.6 m/s. The thermodynamic efficiency of dust devils after improvement was significantly higher than that before improvement. The values were improved by 84.7%, 63.9%, 25.6%, 13.3%, 12.5%, 22.7%, 26.6%, 26.9%, and 21.4% for every hour from 09:00 to 17:00, respectively. The annual number of dust devil occurrences after improvement was 431, which was 55.2% higher than that before improvement. The total annual duration of dust emission after improvement was 181.3 h, which was 95.9% lower than that calculated using day length before improvement and 31.8% higher than that calculated using sunshine time before improvement. The average vertical dust flux of a single dust devil event after improvement was 0.25 g/(m(2)middots), which was 68.8% lower than that before improvement. The average annual dust emission from dust devils per square kilometer was 320.5 t/km(2) and 15.3 t/km(2) before and after improvement, respectively, indicating that the value after improvement was significantly lower (approximately one-twentieth) than that before improvement.

Automated summary

We aimed to improve and evaluate the dust devil parameterization scheme using intensive observations of meteorological and dust devil data in the desert-oasis ecotone of the Xiaotang region in the northern margin of the Taklimakan Desert in combination with GPS sounding in the hinterland of the desert. The results indicated that the temperature difference between the surface and air at a height of 2 m above the ground suitable for dust devil formation was 16℃. In addition, the suitable wind speed (2 m height above ground surface) was 3.2-3.6 m/s. The thermodynamic efficiency of dust devils after improvement was significantly higher than that before improvement. The values were improved by 84.7%, 63.9%, 25.6%, 13.3%, 12.5%, 22.7%, 26.6%, 26.9%, and 21.4% for every hour from 09:00 to 17:00, respectively. The annual number of dust devil occurrences after improvement was 431, which was 55.2% higher than that before improvement. The total annual duration of dust emission after improvement was 181.3 h, which was 95.9% lower than that calculated using day length before improvement and 31.8% higher than that calculated using sunshine time before improvement. The average vertical dust flux of a single dust devil event after improvement was 0.25 g/(m(2)middots), which was 68.8% lower than that before improvement. The average annual dust emission from dust devils per square kilometer was 320.5 t/km(2) and 15.3 t/km(2) before and after improvement, respectively, indicating that the value after improvement was significantly lower (approximately one-twentieth) than that before improvement.