MAO Rui^1,2, GONG DaoYi¹, SHAO YaPing³, WU GuangJian⁴ & BAO JingDong²

¹ State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China;

² Department of Physics, Beijing Normal University, Beijing 100875, China;

³ Institute of Geophysics and Meteorology, University of Cologne, Cologne D-50923, Germany;

⁴ Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China.

 

Abstract: Although the Tibetan Plateau is widely thought as a potential dust source to the atmosphere over East Asia, little is known about the temporal changes of Tibetan dust activities and Tibetan dust source strength. In this study, we address these two issues by analyzing dust storm frequencies and aerosol index through remote sensing data and by means of numerical simulation. The findings indicate that monthly dust profiles over the Tibetan Plateau vary significantly with time. Near the surface, dust concentration increases from October, reaches its maximum in February-March, and then decreases. In the middle to upper troposphere, dust concentration increases from January, reaches its maximum in May-June, and decreases thereafter. Although Tibetan dust sources are important contributors to dust in the atmosphere over the Tibetan Plateau, their contribution to dust in the troposphere over eastern China is weaker. The contribution of Tibetan dust sources to dust in the atmosphere over the Tibetan Plateau decreases sharply with height, from 69% at the surface, 40% in the lower troposphere, and 5% in the middle troposphere. Furthermore, the contribution shows seasonal changes, with dust sources at the surface at approximately 80% between November and May and 45% between June and September; in the middle and upper troposphere, dust sources are between 21% from February to March and less than 5% in the other months. Overall, dust aerosols originating from the Tibetan Plateau contribute to less than 10% of dust in East Asia.

 

Keywords: Tibetan Plateau, dust aerosol, aerosol index, numerical dust modeling, dust sources.