Deposition velocity of PM2.5 in the winter and spring above deciduous and coniferous forests in Beijing, China.
To estimate the deposition effect of PM2.5 (particle matter with aerodynamic diameter <2.5 µm) in forests in northern China, we used the gradient method to measure the deposition velocity of PM2.5 during the winter and spring above a deciduous forest in Olympic Forest Park and above a coniferous forest in Jiufeng National Forest Park. Six aerosol samplers were placed on two towers at each site at heights of 9, 12 and 15 m above the ground surface. The sample filters were exchanged every four hours at 6∶00 AM, 10∶00 AM, 2∶00 PM, 6∶00 PM, 10∶00 PM, and 2∶00 AM. The daytime and nighttime deposition velocities in Jiufeng Park and Olympic Park were compared in this study. The February deposition velocities in Jiufeng Park were 1.2±1.3 and 0.7±0.7 cm s-1 during the day and night, respectively. The May deposition velocities in Olympic Park were 0.9±0.8 and 0.4±0.5 cm s-1 during the day and night, respectively. The May deposition velocities in Jiufeng Park were 1.1±1.2 and 0.6±0.5 cm s-1 during the day and night, respectively. The deposition velocities above Jiufeng National Forest Park were higher than those above Olympic Forest Park. The measured values were smaller than the simulated values obtained by the Ruijgrok et al. (1997) and Wesely et al. (1985) models. However, the reproducibility of the Ruijgrok et al. (1997) model was better than that of the Wesely et al. (1985) model. The Hicks et al. (1977) model was used to analyze additional forest parameters to calculate the PM2.5 deposition, which could better reflect the role of the forest in PM2.5 deposition.
College of Soil and Water Conservation, Beijing Forestry University, Haidian District, Beijing, China.
Fengbin
F
Sun
College of Forestry, Beijing Forestry University, Haidian District, Beijing, China.
Zhe
Z
Yin
College of Environmental Engineering, Beijing Forestry University, Haidian District, Beijing, China.
Xiaoxiu
X
Lun
College of Soil and Water Conservation, Beijing Forestry University, Haidian District, Beijing, China.
Yang
Y
Zhao
College of Environmental Engineering, Beijing Forestry University, Haidian District, Beijing, China.
Renna
R
Li
College of Environmental Science and Engineering, Peking University, Beijing, China.
Fangtian
F
Shi
College of Soil and Water Conservation, Beijing Forestry University, Haidian District, Beijing, China.
Xinxiao
X
Yu
D000393:Air Pollutants / Q000032:analysis*; D002681:China; D002947:Cities; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D065928:Forests; D005843:Geography; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D013997:Time Factors
D000393:Air Pollutants; D052638:Particulate Matter