title: Removal efficiency of particulate matters at different underlying surfaces in Beijing.
abstract: Particulate matter (PM) pollution has been increasingly becoming serious in Beijing and has drawn the attention of the local government and general public. This study was conducted during early spring of 2013 and 2014 to monitor the concentration of PM at three different land surfaces (bare land, urban forest, and lake) in the Olympic Park in Beijing and to analyze its effect on the concentration of meteorological factors and the dry deposition onto different land cover types. The results showed that diurnal variation of PM concentrations at the three different land surfaces had no significant regulations, and sharp short-term increases in PM10 (particulate matter having an aerodynamic diameter <10 μm) occurred occasionally. The concentrations also differed from one land cover type to another at the same time, but the regulation was insignificant. The most important meteorological factor influencing the PM concentration is relative humidity; it is positively correlated with the PM concentration. While in the forests, the wind speed and irradiance also influenced the PM concentration by affecting the capture capacity of trees and dry deposition velocity. Other factors were not correlated with or influenced by the PM concentration. In addition, the hourly dry deposition in unit area (μg/m(2)) onto the three types of land surfaces and the removal efficiency based on the ratio of dry deposition and PM concentration were calculated. The results showed that the forest has the best removal capacity for both PM2.5 (particulate matter having an aerodynamic diameter <2.5 μm) and PM10 because of the faster deposition velocity and relatively low resuspension rate. The lake's PM10 removal efficiency is higher than that of the bare land because of the relatively higher PM resuspension rates on the bare land. However, the PM2.5 removal efficiency is lower than that of the bare land because of the significantly lower dry deposition velocity.
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Jiakai
authors: J
authors: Liu
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Lichun
authors: L
authors: Mo
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Lijuan
authors: L
authors: Zhu
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Yilian
authors: Y
authors: Yang
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Jiatong
authors: J
authors: Liu
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.
authors: Dongdong
authors: D
authors: Qiu
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China. Zhenmingzhang@bjfu.edu.cn.
authors: Zhenming
authors: Z
authors: Zhang
authors: College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China. liujl66@bjfu.edu.cn.
authors: Jinglan
authors: J
authors: Liu
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000032:analysis*; D000068476:Beijing; D004784:Environmental Monitoring / Q000379:methods*; D008685:Meteorological Concepts; D052638:Particulate Matter / Q000737:chemistry*; D012621:Seasons; D014919:Wind
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Dry deposition; Meteorological factors; Particulate matter; Removal efficiency; Underlying surfaces