Modeling dust emission in alpine regions with low air temperature and low air pressure – A case study on the Qinghai-Tibetan Plateau (QTP)

Abstract

• Variations of temperature and pressure could impact dust emission process. • Air density is an important parameter in dust emission modeling. • The improved model could simulate precisely the dust emission in the QTP. • The dust emission in the QTP mainly occurred in winter and early spring. Dust emission is one of the important segments of the circulation of materials between lithosphere, atmosphere, and ocean systems. However, studies on dust emission have mainly concentrated on arid and semiarid regions with few studies focused on dust emission in alpine areas, where having lower air temperatures and lower air pressure environments. The lower air temperature and lower air pressure could significantly impact the air density and make the entrainment and transport of dust different from those at lower altitudes. The lack of accurate studies on dust emission in alpine regions has resulted in large uncertainties in the global dust budget and brought large challenges in controlling aeolian hazards in alpine regions. To bridge this gap, we took the air density as an important parameter to simulate dust emission in the Qinghai-Tibetan Plateau (QTP), where has typical low air-temperature and low air-pressure environments. The measured data showed that the lower air temperature and low air pressure affect the particle size distributions (PSDs) of aeolian sediment, the threshold velocity (TFV) as well as the dust emission rate. Herein, we introduced air density as an important factor to improve a dust emission model, and the validated results showed that the deviations of the simulated horizontal sand flux and vertical dust flux were less than 30% and 35%, respectively. Using the improved model, we could exactly depict the spatial and temporal distribution of dust emission in the QTP. The results shown, our model could exactly depict the spatial and temporal distribution of dust emission in the QTP. We believe that the improvement of the model could offer a new perspective on dust emission in environments with lower air temperature and lower air pressure, and the simulated results could provide valuable data for global dust budget estimation.