title: Estimation of daily PM2.5concentration and its relationship with meteorological conditions in Beijing.
abstract: When investigating the impact of air pollution on health, particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5) is considered more harmful than particulates of other sizes. Therefore, studies of PM2.5have attracted more attention. Beijing, the capital of China, is notorious for its serious air pollution problem, an issue which has been of great concern to the residents, government, and related institutes for decades. However, in China, significantly less time has been devoted to observing PM2.5than for PM10. Especially before 2013, the density of the PM2.5ground observation network was relatively low, and the distribution of observation stations was uneven. One solution is to estimate PM2.5concentrations from the existing data on PM10. In the present study, by analyzing the relationship between the concentrations of PM2.5and PM10, and the meteorological conditions for each season in Beijing from 2008 to 2014, a U-shaped relationship was found between the daily maximum wind speed and the daily PM concentration, including both PM2.5and PM10. That is, the relationship between wind speed and PM concentration is not a simple positive or negative correlation in these wind directions; their relationship has a complex effect, with higher PM at low and high wind than for moderate winds. Additionally, in contrast to previous studies, we found that the PM2.5/PM10ratio is proportional to the mean relative humidity (MRH). According to this relationship, for each season we established a multiple nonlinear regression (MNLR) model to estimate the PM2.5concentrations of the missing periods.
authors.affiliation: LREIS, Institute of Geographic Sciences and Nature Resources Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: yinq@lreis.ac.cn.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yin
authors.affiliation: LREIS, Institute of Geographic Sciences and Nature Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China. Electronic address: wangjf@lreis.ac.cn.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: LREIS, Institute of Geographic Sciences and Nature Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Maogui
authors.initials: M
authors.lastname: Hu
authors.affiliation: LREIS, Institute of Geographic Sciences and Nature Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Hoting
authors.initials: H
authors.lastname: Wong
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D000068476:Beijing; D004784:Environmental Monitoring; D008685:Meteorological Concepts; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: PM(10) concentration; PM(2.5) concentration estimation; Wind direction; Wind speed