Abstract
Water-soluble ions such as sulfate may have great impacts on atmospheric pollution. To determine the deposition effect of PM2.5 sulfates, the major PM2.5 constituents, in the forest canopy in Beijing, China, an investigation was carried out in an urban forest, Olympic Forest Park, and a suburban forest, Jiufeng National Forest Park. We measured the vertical distributions of sulfate by using monitoring towers in the two forests at the same times in March and May 2013. Sulfate (SO42−) was predominant in all PM2.5 water-soluble inorganic ions, with a proportion >40%. The vertical concentration of SO42− increased with height, and the average sulfate concentration in Olympic Forest Park was higher than that in Jiufeng National Forest Park. Results also revealed that meteorological conditions had significant impacts on both the sulfate concentration and the deposition velocity. In winter, the deposition of SO42− through the canopy was not obvious in the two forest parks, which was quite the opposite in spring. The deposition velocity in the daytime was higher than that in the nighttime in both Olympic Forest Park (0.9 ± 1.0 cm/s vs. 0.4 ± 0.3 cm/s) and Jiufeng National Forest Park (1.3 ± 1.2 cm/s vs. 0.8 ± 0.8 cm/s). While Jiufeng National Forest Park turned out to have a higher average sulfate deposition velocity than Olympic Forest Park.
Highlights
PM2.5 includes all particulate matter that has an aerodynamic diameter of 2.5 microns or smaller.PM2.5 represents only a small percentage in the air, but is considered as one of main components in atmospheric pollution
Studies on PM2.5 sulfates have mainly focused on aspects related to concentrations, size distribution characteristics, source analysis, and seasonal and diurnal variations of PM2.5 [4,5,6]
This observation indicated a downward flux of the particulate sulfate, which can be explained by the potential high absorption ability of the forests
Summary
PM2.5 includes all particulate matter that has an aerodynamic diameter of 2.5 microns or smaller. Water-soluble ions are important parts of PM2.5 and have a great influence on atmospheric pollution [2]. The process of deposition is an important way to remove particulate matter from the air, and the crown canopy is an extremely important boundary between the atmospheric environment and the forest ecosystem. As the As capital of China, which happens to be deeply some countries otherChina than China the capital of China, which happens to be affectedaffected by haze,by research on the deposition characteristics of PM2.5 sulfate onsulfate forest systems. Research on the deposition characteristics of PM2.5 on forestinsystems is of great importance and will help to determine the effect of these ecosystems on PM. 2.5 sulfate in Beijing is of great importance and will help to determine the effect of these ecosystems on PM2.5 removalremoval in China
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
