title: Spatial and temporal variation of haze in China from 1961 to 2012.
abstract: The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data from 1961 to 2012 and daily PM10 concentrations from 2003 to 2012 were employed in this study. The results indicate that the annual-average hazy days at all stations have been increasing rapidly from 4 days in 1961 to 18 days in 2012. The maximum number of haze days occur in winter (41.1%) while the minimum occur in summer (10.4%). During 1961-2012, the high occurrence areas of haze shifted from central to south and east regions of China. The Beijing-Tianjin-Hebei (Jing-Jin-Ji) region, Shanxi, Shaanxi, and Henan Province are the high occurrence areas for haze, while the Yangtze River Delta (YRD) and the Pearl River Delta (PRD) have become regions with high haze occurrences in the last 25 years. Temperature and pressure are positively correlated with the number of haze days. However, wind, relative humidity, precipitation, and sunshine duration are negatively correlated with the number of haze days. The key meteorological factors affecting the formation and dissipation of haze vary for high and low altitudes, and are closely related to anthropogenic activities. In recent years, anthropogenic activities have played a more important role in haze occurrences compared with meteorological factors.
authors: National Meteorological Information Center, China Meteorological Administration, Beijing100081, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: gdla2008@sina.com.
authors: Rui
authors: R
authors: Han
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China. Electronic address: shxwang@tsinghua.edu.cn.
authors: Shuxiao
authors: S
authors: Wang
authors: National Meteorological Information Center, China Meteorological Administration, Beijing100081, China.
authors: Wenhai
authors: W
authors: Shen
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Jiandong
authors: J
authors: Wang
authors: Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
authors: Kang
authors: K
authors: Wu
authors: National Meteorological Information Center, China Meteorological Administration, Beijing100081, China.
authors: Zhihua
authors: Z
authors: Ren
authors: National Meteorological Information Center, China Meteorological Administration, Beijing100081, China.
authors: Mingnong
authors: M
authors: Feng
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D000068476:Beijing; D002681:China; D004784:Environmental Monitoring; D006813:Humidity; D008685:Meteorological Concepts; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D013696:Temperature; D014887:Weather; D014919:Wind
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Anthropogenic activities; China; Haze; Interannual trend; Meteorological factors; Spatial distribution