Re-evaluating the distribution and variation characteristics of haze in China using different distinguishing methods during recent years.
Re-evaluating the distribution and variation characteristics of haze in China using different distinguishing methods during recent years.
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DOI：
10.1016/j.scitotenv.2020.138905
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Lina Gao;Lijuan Cao;Yong Zhang;P. Yan;Junshan Jing;Qing Zhou;Yimeng Wang;Shanshan Lv;
中科院分区：
文献类型：
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作者：
Lina Gao;Lijuan Cao;Yong Zhang;P. Yan;Junshan Jing;Qing Zhou;Yimeng Wang;Shanshan Lv;
利用2013年至2018年在中国502个站点收集的每小时能见度、相对湿度（RH）和pm2.5质量浓度观测数据，通过不同的方法识别雾霾。本研究将一种新的雾霾识别方法（MGB）与目前使用的其他方法（M80和M90）进行了对比。与其他方法相比，MGB方法在表达细颗粒物污染特征方面具有优势，特别是在高湿地区。中国MGB获得的日均pm2.5与霾小时的相关系数均值为0.69，高于其他两种方法识别的日均pm2.5与霾小时的相关系数。与M80相比，MGB和M90对霾的识别受RH日变化和月变化的影响较小。无论采用哪种霾识别方法，中国约75%的霾发生在相对湿度超过60%或pm2.5质量浓度低于105 μg/m3时。雾霾具有明显的区域分布特征，京津冀及其周边地区和长江中下游地区相对较高。MGB方法确定的中国大陆6年平均年总雾霾时间为1167小时。与MGB相比，M80低估了- 34%的雾霾小时，M90产生了较小的正高估，高估了18%。无论采用何种识别方法，中国及三大经济区域的年总雾霾时数均呈现显著的减少趋势。本研究通过自动能见度测量得到雾霾的日变化。MGB和M90识别的霾时日周期相似，而M80识别的霾时日周期受RH日变化的影响有所不同。霾时冬高夏低。
Haze is identified via different methods using hourly visibility, relative humidity (RH) and PM2.5mass concentration observations collected from 2013 to 2018 at 502 stations in China. An inter-comparison of a new haze identification method (MGB) and other currently used methods (M80 and M90) is performed in this research. Compared with other methods, the MGB method has an advantage in the expression of fine particle pollution characteristics, especially in high humidity areas. The mean value of the correlation coefficient of the daily mean PM2.5and daily haze hour obtained by MGB in China is 0.69 which is higher than the correlation coefficients of the daily mean PM2.5and haze hour identified by the other two methods. Compared with M80, the haze identified by MGB and M90 is less influenced by daily or monthly variations of RH.Approximately 75% of haze occurs when the RH is exceeds 60% or the PM2.5mass concentration is below 105 μg/m3over China, no matter which haze identification method is used. Haze has obvious regional distribution characteristics and is relatively higher in Beijing-Tianjin-Hebei and its surrounding areas, and the middle and lower reaches of the Yangtze River. The 6-year mean annual total haze identified by the MGB method is 1167 h for mainland China. Compared with MGB, M80 underestimates the haze hour by −34%, and M90 produces a smaller positive overestimation by 18%. The annual total haze hour of China and its three major economic regions shows significant decreasing trends regardless of the identification method used. Daily variation of haze is obtained in this research via automatic visibility measurement. The daily cycles of haze hour identified by MGB and M90 are similar, whereas that identified by M80 behaves differently affected by daily variation of RH. Haze hour is high in winter and low in summer.