华东地区PM2.5分布特征及其成因分析
An Analysis of PM2.5 Distribution, Variation and Formation in the Eastern China for 2000-2015
中文摘要：
利用2000—2015年MODIS气溶胶光学厚度产品，采用参数化方法反演得到了华东地区地面PM2.5时空分布产品。从季节特征来看，PM2.5表现出春夏低、秋冬高的特点。而PM2.5年际变化呈现出从2000年开始稳定增加，2007年达到最高值，之后逐渐下降的趋势。这种年变化趋势不仅与区域污染物排放有密切关系，同时也与天气背景环流的年际尺度变化有很大关系。通过对不同季节的PM2.5进行EOF分解，发现春季的年变化受极涡强度影响较大，夏季年变化主要受西太平洋台风数量、北半球副高脊线位置以及太平洋—北美遥相关型指数支配。秋季年变化与太阳黑子活动及亚洲区极涡面积关系密切。冬季年变化受冷空气影响次数和Ni?o A区（25°—35°N，130°—150°E）海表温度距平指数支配。各季节天气影响因子的组合效应能够很好地反应出区域PM2.5的年变化特征，表明在全球气候变暖的背景下，中国东部环流形式的改变对PM2.5区域分布的变化有着不容忽视的影响。
中文关键词：
PM2.5，MODIS，环流因子，华东地区
KeyWords：
PM2.5, MODIS, circulation index, East China
Abstract：
Using satellite-based PM2.5 data for 2000-2015, we found that the temporal-spatial variation of PM2.5 in the Eastern China was characterized by the high concentrations in the northern part and low in the southern part of the East China with seasonally high in autumn and winter but low in spring and summer, that the regional averaged PM2.5 concentration showed an approximative high of 70.69 μg·m-3 and the low of 51.65 μg·m-3 in 2007 and 2000, respectively. The available emissions of atmospheric compositions showed asimilar yearly variation trend as the PM2.5 even the synchronization is not meet to each other of composition, implying that the intensity of anthropogenic emissions dominates the temporal variation of PM2.5 in East China. The empirical orthogonal function analysis demonstrated that the dominant variability in the seasonal PM2.5 in East China was closely associated with the specific climate index of Asia Polar Vortex intensity in the spring, the Western North Pacific Typhoon number, the Northern Hemisphere subtropical high ridge position and the Pacific/ North American Pattern for the leading mode and the Kuroshio Current SST for the second mode in the summer, the Total Sunspot Number and the Asia Polar Vortex Area for the leading mode and the Pacific polar vortex Intensity, the number of landing typhoon on China and the East Asian trough intensity for the second mode in the autumn, the cold air activity and the Ni?o A (25°—35°N, 130°—150°E) SSTA for the leading mode and the Pacific Decadal Oscillation together with the Pacific polar vortex area for the second mode in the winter. Therefore, apart from anthropogenic emissions effect, our results also provide robust evidence that the climate factor has played a significant role in modulating the PM2.5 in the eastern China for the 16 years.