长三角地区近10年气溶胶时空分布特征

Temporal and Spatial Distributions of Aerosols over the Yangtze River Delta Region in Recent 10 Years

该文利用2003年3月至2013年2月间MODIS遥感气溶胶三级产品资料,分析了我国东部长三角地区气溶胶光学厚度(AOD)、Angstrom波长指数、细粒子比例和垂直柱质量浓度的时空分布及其变化特征。长三角地区的AOD呈现出北高南低分布,北部(30°N以北)年平均约为0.6~0.7,南部普遍低于0.5。AOD季节分布变现为春夏高、秋冬低,夏季最高。10年间,长三角地区AOD呈现出波动增长趋势,并表现出地区差异,北部增长较南部快。Angstrom波长指数表现为南高北低,春冬低夏秋高,总体变化趋势不显著。冬春季细粒子比例低于夏秋季,北部细粒子比例普遍低于南部,但北部增长率高于南部。从气溶胶垂直柱浓度分布来看,北部高于南部,高值中心在江苏、上海一带,低值区在浙江一带。春季气溶胶柱浓度最高,秋季最低。气溶胶柱浓度北部增长较快,南部有所下降。

Using the MODIS Level 3 aerosol products, the temporal and spatial distributions of aerosol optical depth（AOD）,Angstrom exponent（AE）, fraction of fine-mode aerosol（FMF） and aerosol columnar mass concentration are analyzed during March 2003 to February 2013 over the Yangtze River Delta Region. It presents a distinct distribution of AODs showing high AODs in the northern part（30°N north） and low in the southern. The annual means of AOD are about 0.6 ~0.7 in the northern part and lower than 0.5 in the southern, respectively. The mean AODs of spring and summer are higher than those of autumn and winter, with the highest one in summer. It shows a fluctuant increasing trend of AOD in this region, which increases faster in the northern part than the southern. The Angstrom exponent presents no significant growth trend and a distribution of high in the southern part and low in the northern. It shows a seasonal feature of high in spring and winter and low in summer and autumn. The FMFs of spring and winter are lower than those of summer and autumn. It shows lower FMFs in the north-ern part than the southern, while the growth rate of the northern is faster than the southern. To the column mass concentration of aerosols, it shows higher value in the northern part, with the highest values in the region of Jiangsu and Shanghai and the lowest in Zhejiang. The highest column mass concentration is in spring, while the lowest in autumn. It shows an increasing trend of column mass concentration in the northern part, while decreasing in the southern.