新疆沙尘源状况及其沙尘气溶胶释放条件分析

沙尘气溶胶是干旱、半干旱区大气中重要的组成物质, 沙尘天气多发是该区域沙尘气溶胶含量高的主要原因。新疆1/4的土地被沙漠覆盖,塔里木盆地绝大部分地区沙土和沙壤土占地比率大于60%,沙漠沙以细沙为主, 特殊的下垫面为沙尘天气的形成提供了丰富的沙源;沙漠周围的边缘地带、河流两岸、古河道中的土壤类型中粒径小于2.5 μm和粒径小于10 μm的土壤颗粒物中细颗粒物分别达到了50%和20%,是大气沙尘气溶胶中细颗粒物的主要来源和潜在来源。沙尘天气的产生受大风、降水、植被覆盖度、下垫面性质以及大气环流等多种因素的影响。

Status of Dust Sources and Aerosol Formatting Condition Analysis in Xinjiang

Sand-dust aerosols are main substances in air composition over arid and semiarid areas, and frequent sand-dust weather is the key cause. About 25% area of Xinjiang is covered by desert; especially the area of sandy soil in most regions of the Tarim Basin is more than 60%. The underlying surfaces that are covered predominately by fine sands provide sufficient sand sources for sand-dust weather formation. The content of soil particles with diameter less that 2.5 μm or less that 10 μm is respectively up to 50% and 20% in areas of desert rim, river side, and ancient river bed. They are the main sources and latent sources of fine particles in dust aerosol. Whether the sand-dust weather happens it has multiple influencing factors, such as gale, precipitation, vegetation coverage, underlying feature, atmospheric current, etc.