长株潭城市群气溶胶时空分布与传输规律

为研究长株潭城市群大气污染时空演化特征及潜在传输规律，采用2008~2016年中分辨率成像光谱仪（MODIS）MAIAC气溶胶光学厚度（AOD）数据，分析长株潭城市群近10a来AOD演化特征.在此基础上，利用拉格朗日混合型单粒子轨迹模式（HYSPLIT）及全球资料同化系统（GDAS）气象要素数据研究大气污染物潜在传输规律.结果表明，长株潭城市群AOD呈现下降趋势，并以春、夏季下降幅度最为显著.空间上，AOD总体呈北高南低、西高东低分布特征，并与经济发展、城市化水平等因素密切相关.此外，长株潭城市群大气污染物向外长距离传输（>1500km）、中距离传输（500~1500km）以及局地传输（0~500km）比率分别为17.89%、36.45%和45.66%，主要影响湖北、江西、安徽、广东、广西、江苏和浙江等地区.研究结果有助于理解长株潭城市群大气污染的时空变化规律，同时为区域“联防联控”、建设“美丽中国”提供科学的辅助依据.

Spatial-temporal distribution and transport characteristic of aerosol in Changsha-Zhuzhou-Xiangtan urban agglomeration

In order to capture the spatial-temporal variations and regional transport characteristics of air pollution in Changsha- Zhuzhou-Xiangtan urban agglomeration, the spatial-temporal variations of aerosol optical depth (AOD) were analyzed using the MODIS MAIAC data from 2008 to 2016. On this basis, the potential transport characteristics of air pollutant were studied using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and global data assimilation system (GDAS) meteorological element data. Results showed that AOD showed a downward trend, with the most significant decline in spring and summer. The spatial distribution of AOD was mainly characterized by the high in west and north while low in east and south. In the meantime, it was closely related to economic development and urbanization. In addition, the long-distance transportation (>1500km), medium-distance transportation (500~1500km) and local transportation (0~500km) rates of air pollution were 16.56%, 30.7% and 52.74%, respectively. The potential diffusion of air pollutant mainly affected Hubei, Jiangxi, Anhui, Guangdong, Guangxi, Jiangsu and Zhejiang. This study not only helps to understand the spatial-temporal variations of air pollution in the Changsha-Zhuzhou- Xiangtan urban agglomeration, but also provides a scientific auxiliary basis for the regional joint prevention and control and the beautiful China construction.