秸秆燃烧和沙尘对气溶胶光学特性的影响

利用多年积累的我国几个典型地区的太阳辐射计观测数据,反演了秸秆燃烧和沙尘日及其前后晴朗日的气溶胶光学厚度(AOD)和表征粒子尺度的ngstrm指数(α),并运用观测结果和反演数据对已知气溶胶源予以验证。对比分析了多个典型地区源自秸秆燃烧和沙尘的气溶胶光学特性,结果显示,秸秆燃烧和扬尘时AOD都大幅增加,而α在秸秆燃烧时比通常晴朗日增大,取值大于1.3;在扬尘时比通常晴朗日明显减小,取值小于0.5。另外,不同地区不同气溶胶源的AOD与α的关系明显不同。分析结果表明,α可作为秸秆燃烧和沙尘天气的一个标志参数,为生物燃烧性有机碳黑气溶胶光学特性的检测方法提供依据,也可为分析我国西北城市地区受周边沙漠的影响程度提供有益参考。

Influence of straw burning and dust on aerosol optical properties

The Aerosol Optical Depth (AOD) and Ångström indexes (α) influenced by straw burning, dust, and some sunny days were invertedby using the long-term measurement data from a sun-photometer in several typical regions of China. Then, the given aerosol sources were verified by the observed data and retrieved results. The optical characteristics of aerosols influenced by straw burning and dust were analyzed in several typical regions of China. The results show that the AOD obviously increases for the cases with straw burning and dust in the city. The α is larger in the periods of straw burning than that in clear days, the values during straw burning days usually are greater than 1.3. However, the α is smaller during dust days than that during clear days, which is usually less than 0.5. The relationship between the AOD and the α influenced by different aerosols in different zones is evidently different. The results indicate that the α can be a benchmark parameter of straw burning and dust to lay a basis for detection methods of organic black carbon aerosol optical properties and also to provide a reference for research of the effect degrees of urban areas of northwest China by surrounding deserts .