The trend of persistent regional haze in Anhui Province and corresponding characteristics of aerosol pollution
Shi Chun-e1,2, ZHANG Hao1,2, YANG Yuan-jian1,2, ZHANG Hong-qun1,2
1. Anhui Institute of Meteorological Sciences, Key Laboratory for Atmospheric Sciences and Remote Sensing of Anhui Province, Hefei 230031, China;
2. Shouxian National Climatology Observatory, Shouxian 232200, China
According to weather and climate characteristics, Anhui was divided into three sub-regions. Then, a regional haze day was defined as "more than one third of observational sites in a region reached standards of haze day", and when a region experienced a consecutive 4d or more regional haze days it was defined as a persistent regional haze event. Using data of meteorology, environment, and remote sensing from satellite and ground-based lidar, the spatial-temporal distributions of persistent reginal haze in Anhui province and corresponding aerosol pollution were investigated. The annual regional haze days showed increasing trends since 1980 in the two sub-regions to the south of Huai River, while it showed evident increasing trend after 2000 in region along and to the north of Huai River. Since 1980, persistent haze events in cities in Anhui province showed increasing trend, but with large differences among cities in the same sub-region. Since year of 2000, the occurrence of persistent regional haze events increased obviously, even emerging consecutive 7~10d or more than 10d regional haze events. Persistent regional haze occurred most in the region between Yangtze and Huaihe Rivers, and least in the region along and to the south of Yangtze River, with more than 62% occurred in winter. Regional haze usually corresponded to regional high humidity and small wind speed in meteorological conditions, accompanied by high concentration of aerosol pollution, e.g. regional AOD over 0.9, which was around 2.3 times of the clear day. Aerosol was concentrated below the lowest 400m on regional haze days, e.g. the near surface extinction coefficient was around 2 to 2.5 times of the regular haze days and 3 to 5 times of the clear days; as for PM2.5 pollution at ground level, on a regional haze day, the probability of at least one city having AQI over 100 (lower AQI limit of light pollution) exceeded 75%.
石春娥, 张浩, 杨元建, 张宏群. 安徽省持续性区域霾污染的时空分布特征[J]. 中国环境科学, 2018, 38(4): 1231-1242.
Shi Chun-e, ZHANG Hao, YANG Yuan-jian, ZHANG Hong-qun. The trend of persistent regional haze in Anhui Province and corresponding characteristics of aerosol pollution. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(4): 1231-1242.
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