Research On Sand Dust Spatial Distribution In Winter And Spring In Northern China And Dust Source And Path

The daily dust information was extracted from MODIS L1B data of 920 days in winter and spring from 2014?2018 in northern of China by using brightness temperature difference(BTD)algorithm,make study the spatial distribution of dust frequency,carry out analysis of high-frequency dust source area and statistical dust movement path.The results shows:(1)The eastern edge of the Taklimakan Desert and the southern edge of the Korqin sand are the most frequent in winter in northern China(147?184 times);the southern edge of the Taklimakan Desert,the northern edge of the Kummatog desert,and the northern edge of the Batang-jirind desert are the most frequent in spring(208?259 times).(2)In winter,the region with high frequency of moderate dust activities is mainly in the eastern edge of the Taklimakan Desert,and no severe dust activities occurs;in spring,the region with high frequency of moderate and severe dust activities is located in the northwest of the Taklimakan Desert.(3)The dust source is mainly located in the transit zones from Alluvial fan,via Gobi,to the edge of Desert,filled with dry riverbed,dry lake,and degraded oasis.The surface in the region covers fine sand particles and provide rich sand material for the high-frequent and high-concentrated sand and dust.The fine particles are easy to release to atmosphere and difuse to the surrounding region through the local dust circulation process.(4)Winter dust moving path has west,northwest two types of moving path,the quantity of the west path dominates;In spring,there are west,northwest and Xinjiang southern basins three types of dust moving paths,and the northwestern paths dominates.