Improvement and Evaluation of a Parameterization Scheme for Assessing Dust Devils as Dust Emission in the Northern Margin of the Taklimakan Desert

Based on meteorological and dust devil intensification observation data in the desert transition zone of the Xiaotang region in the northern margin of the Taklimakan Desert, and combined with GPS sounding in the hinterland of the Taklimakan Desert, this study investigated the improvement and evaluation of the dust devil parameterization scheme. The results indicate that the thermodynamic efficiency of dust devils after improvement was significantly higher than that before improvement, improving the values by 84.7%, 63.9%, 25.6%, 13.3%, 12.5%, 22.7%, 26.6%, 26.9%, and 21.4% for the hourly intervals from 09:00–17:00, respectively. The annual occurrence of dust devils after improvement was 431 times, 55.2% more than before improvement. The correlation coefficients of convective boundary layer height after improvement was 0.96, higher than that before improvement (0.908). After the improvement, the total annual dust emission time was 181.3 h, 95.9% less than that calculated using the day length before improvement, and 31.8% more than that calculated using sunshine time before improvement. After the improvement, the average vertical dust flux of a single dust devil was 0.25 m2/s, 68.8% less than that before improvement. After the improvement, the average annual dust emission from dust devils per square kilometer was 15.3 t/km2, significantly lower than the value of 320.5 t/km2 before the improvement, approximately one-twentieth of the value.