中国各省区近10年遥感气溶胶光学厚度和变化

Chinese province-level variations and trends in aerosol optical depth from recent 10 years of remote sensing data

用2000—2009年MODIS大气气溶胶光学厚度(AOD))资料,分析中国29个省(区、市)AOD多年平均值和年际间变化趋势。中国10年平均AOD高值区主要集中在华北、华中、华南和新疆,低值区主要在青藏高原、西北(除新疆外)、东北和西南地区。中国有13个省(市、区)多年平均AOD超过0.4。最高为0.735(江苏)。只有西藏和黑龙江的AOD小于0.2,其余15个省区市的AOD在0.2至0.3之间。除新疆外,中国的AOD高值区全部集中在工业发达和人口密集的地区。中国年际间AOD的变化为上升趋势。近10 a来AOD增长的倾向率为0.019/10a,即增加了4.3%。其中在2000—2007年间的上升最为明显,在2007年达到近10 a来的最高峰(0.437 6),2008年以后中国的AOD开始出现下降趋势,2009年达到近10 a来最低值(0.372 0)。有17个省区市AOD气候学变化倾向率为正值,变化的范围为0.006~0.099/10a。有12个为负值,变化的范围为-0.037^-0.003/10a。出现AOD增加和减少趋势的区域两极分化,即高排放地区继续增加,低排放地区持续减少。

Using the aerosol optical depth（AOD） data of MODIS from 2000 to 2009,annual AOD-averages and interannual AOD-changes over 29 Chinese province-level divisions are analyzed.High AOD-means over the 10 years concentrated in North,Central,and South China as well as Xinjiang in Northwest China,while low AOD-means were distributed in Qizhang Plateau,Northwest（excluding Xinjiang）,Northeast and Southwest China.In 13 province-level divisions,the annul AOD-averages exceeded 0.4 with the maximal value of 0.735 in Jiangsu Province.In 15 province-level divisions,the AOD-averages ranged between 0.2 and 0.3 with the lowest values（〈0.2） in Xizhang and Helongjiang.Except Xinjiang,the high AOD-regions were located in the province-level divisions with high industrialization and dense population in China.Positive trends in annual AOD averaged over the all Chinese divisions are found with the rate of 0.019/10a or a 10-year increase of 4.3%.Averaged over all Chinese divisions,the annual AOD peaked in 2007 with the value of 0.4376 and then decline to 0.3720 in 2009,the lowest value for the 10 years.17 province-level divisions in the high-emission regions of China experienced the positive trends in AOD of 0,006-0.099/10a,while 12 divisions in the low-emission areas presented the negative trends between-0.037 and-0.003/10a,which could imply a polarization of AOD-variations in China.