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Characteristics of Taklimakan dust emission and distribution: A satellite and reanalysis field perspective
Author(s) -
Ge J. M.,
Huang J. P.,
Xu C. P.,
Qi Y. L.,
Liu H. Y.
Publication year - 2014
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2014jd022280
Subject(s) - perspective (graphical) , satellite , environmental science , field (mathematics) , distribution (mathematics) , atmospheric sciences , remote sensing , meteorology , geology , computer science , geography , physics , mathematics , astronomy , artificial intelligence , mathematical analysis , pure mathematics
Dust particles from the Taklimakan Desert can be lofted vertically up to 10 km due to the unique topography and northeasterly winds associated with certain synoptic conditions. Then they can be transported horizontally to regions far downwind by westerlies. We combined data from the Multiangle Imaging Spectroradiometer (MISR) and the Cloud‐Aerosol Lidar with Orthogonal Polarization to investigate the three‐dimensional distribution of dust over the Taklimakan Desert and surrounding areas. During spring and summer, a dust belt with high aerosol optical depths (AOD) extends eastward from the Taklimakan Desert to the Loess Plateau along the Hexi Corridor and southward to the Tibetan Plateau. However, the dust extinction coefficients decrease rapidly from 0.340 km −1 near surface to 0.015 km −1 at 5 km in spring, while the extinction values vary within 0.100 ± 0.020 between the altitudes of 1.6 and 3.5 km and decrease to 0.023 km −1 at 5 km in summer, indicating that dust aerosol is relatively well mixed vertically. We further used MISR daily AOD to identify high‐ and low‐dust days and then analyzed composite difference patterns of temperature, geopotential height, and wind between high‐ and low‐dust days. It was found that although the synoptic situations of spring and summer are quite different, there are two common features: a strong anticyclonic wind anomaly over the Taklimakan at 500 hPa and an enhanced easterly wind over the Tarim Basin at 850 hPa for the two seasons. These conditions are favorable for dust entrainment from the dry desert surface, vertical lofting, and horizontal transport.