环渤海地区气溶胶光学厚度数据选取及时空特征分析

基于太阳光度计观测数据，对气溶胶光学厚度业务化产品数据进行了验证，结果显示该数据在环渤海地区并不完全适用.基于归一化植被指数（NDVI）进行数据融合，得到适合环渤海区域AOD融合数据.利用2009年1月到2018年12月的新融合数据，统计出研究区域气溶胶光学厚度空间和时间的分布变化特征.根据月均AOD的空间分布和时间序列变化，高值月分别出现在易出现沙尘暴、雾霾的2月和雨热同期的6月；季节分析中，区域多年平均夏季表现为最高值（0.433），秋季表现为最低值（0.275）；年际变化显示，环渤海99.8%区域AOD呈降低趋势.空间分布表明，在环渤海地区AOD呈现东南高西北和东北低.

Analysis of temporal and spatial characteristics and data selection of aerosol optical depth in the Bohai Rim Region

The operational data of aerosol optical depth (AOD) were compared with the observation data of the solar photometer. Results show that the operational data are not completely applicable in the Bohai Rim region. Therefore new AOD fusion data which were suitable for the Bohai Rim region were obtained based on the normalized difference vegetation index (NDVI). Using the new fusion data from January 2009 to December 2018, the spatial and temporal distribution characteristics of AOD in the study area were statistically calculated. The results show that the high-values of AOD appear in February and June as the sandstorms and haze often occur in February and it is hot and rainy in June. Seasonal variations of the regional average AOD show the highest value (0.433)in summer, the lowest value(0.275) in autumn. Inter-annual changes indicate a downward trend in 99.8% of the Bohai Rim region. The spatial distribution of AOD appear high in the southeast and low in the northwest and northeast in the Bohai Rim region.