利用MODIS和MISR资料对APEC会议期间气溶胶时空分布特征的分析

利用卫星遥感的MODIS和MISR数据，对比分析了2014年亚太经合组织（APEC）会议期间（11月3日~12日）及其前后一个月的气溶胶时空分布特征。分析发现APEC会议期间的气溶胶光学厚度（aerosol optical depth, AOD）相比APEC会议前期，在京津冀地区有明显减小，MODIS（MISR）数据显示在京津冀地区AOD减小了38.7%（36.4%），在北京地区减小更多，减小了64.6%（39.9%）。Angstrom指数在京津冀地区的廊坊、保定、衡水等大部分城市，APEC会议期间的Angstrom指数相对前期较小，说明其在APEC会议期间气溶胶粒子的有效半径相对较大。APEC会议期间的细模态气溶胶光学厚度相比APEC会议前期也有所减小，且在北京地区细模态气溶胶光学厚度的下降幅度要大于粗模态气溶胶的下降幅度。

Analysis of the Spatiotemporal Variations of Aerosols During APEC Using MODIS and MISR Data

By using MODIS and MISR data, the spatiotemporal distribution characteristic of aerosols were studied for the period before, during and after Asia-Pacific Economic Cooperation (APEC) Conference 2014 (November 3 to 12). Compared with the month before APEC, the aerosol optical depth (AOD) during APEC shows an apparent decrease in the region of Beijing-Tianjin-Hebei (36°N~41°N, 113.5°E~118.5°E), which decreases by 38.7% (36.4%) according to MODIS (MISR) data. And the AOD decreases more substantially in Beijing, which decreases by 64.6% ( 39.9%). The spatial distribution of the Angstrom exponent shows that in the most of the city of Beijing-Tianjin-Hebei region (e.g. Langfang, Baoding, Hengshui, etc.), the Angstrom exponent during APEC is relatively small, which indicates that the effective radius of the aerosol is relatively large. During APEC, the optical depth of the fine mode aerosol also decreases in comparison with the period before APEC, and it declines more significantly than the optical depth of the coarse aerosol in Beijing.