近58年来长江中游雾和霾的演变特征及其影响因素

Evolution Characteristics and Influencing Factors of Fog and Haze in the Middle Reaches of the Yangtze River in the Past 58 Years

以1961~2018年湖北72个国家站的气象观测资料和NCEP再分析资料为基础,采用代表站分类、时序演变、相关性分析等方法,研究雾和霾的时空分布特征及其影响因素,结果表明:(1)湖北地区的雾和霾空间分布不均,霾多发生在大城市和工业城市,雾多发生在鄂西南山区;1980年前,雾和霾的年代际变化趋势比较一致,之后呈反相,总体上呈现负相关,2005年后霾日较雾日明显增加。(2)城市站与生态站雾日的年变化趋势均是先增加后减少再增加,由增至减的拐点分别出现在1980和1987年,表明城市化进程对雾的生成有影响;霾日变化趋势基本一致,空气污染的年际变化无明显的城乡差异。(3)对于所有站点来说,"区域尺度气候变化、城市化和空气污染(气溶胶污染)"等3个因素对雾的定量影响相当;对于城市站,城市化的影响明显占主导(55%);对于生态站,气溶胶污染的贡献率最高(43%)。

Based on the meteorological observation data of 72 Hubei national stations and NCEP reanalysis data from 1961 to 2018, representative station classification, time series evolution and correlation analysis are applied to study the temporal and spatial distribution characteristics of fog and haze and related influencing factors. Results show that:(1)The spatial distribution of fog and haze in Hubei is uneven. The haze mostly occurs in large cities and industrial cities while the fog mostly occurs in the mountainous area of southwestern Hubei. The interdecadal trend of fog and haze is relatively consistent before 1980 while it is in the opposite phase after 1980 and showing a negative correlation as a whole. After 2005, haze days significantly increase compared to fog days.(2) Annual trend of fog days increases first, then decreases, and then increases at both urban stations and ecological stations. The turning points from increase to decrease appear in 1980 and 1987 respectively, indicating that the process of urbanization has an impact on the formation of fog. Daily trend of haze days is basically the same, and interannual variations of air pollution show no obvious urban-rural differences.(3) For all stations, quantitative effects of "regional-scale climate change, urbanization and air pollution(aerosol pollution)" on fog are nearly equal, while the impact of urbanization is obviously dominant(55%) for urban stations and aerosol pollution has the highest contribution rate(43%)for ecological stations.