학술논문

Chemical composition and seasonal characteristics of fine particles in the plain and mountain area of Gunma / 群馬県平野部および山岳部における微小粒子状物質の季節特性
Document Type
Journal Article
Source
大気環境学会誌 / Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi. 2010, 45(1):10
Subject
Elemental carbon
Gaseous pollutant
Inorganic aerosol
Organic carbon
Secondary formation
Language
Japanese
ISSN
1341-4178
2185-4335
Abstract
The atmospheric aerosols were investigated from April 2003 to March 2006 at Maebashi and Mt. Akagi, both of which are located on the inland Kanto plain. Fine (< 2.1 μm) and coarse (2.1 - 11 μm) particles were collected using an Andersen low-volume air sampler, and the organic carbon (OC), elemental carbon (EC), and ionic components were measured. The mean mass concentrations of the fine particles were 21.7 and 9.4 μg/m3 at Maebashi and Akagi, respectively. The highest concentration of fine particles was observed in spring; nitrate and sulfate were the major components. Sulfate and OC were dominant in summer and fall. Nitrate and sulfate were present in the form of ammonium nitrate and ammonium sulfate, respectively. We compared the concentrations of the ionic components in the fine particles collected at Maebashi and Akagi and found that the distribution of ammonium sulfate was widespread, while that of ammonium nitrate was localized to Maebashi. The localized distribution of ammonium nitrate at Maebashi was attributed to the high concentration of gaseous ammonia in this region and transport of gaseous nitric acid from the southern Kanto area. The mass concentration of fine particles was estimated by a chemical mass closure model. The ammonium nitrate, ammonium sulfate, and organic aerosols accounted for a large fraction of the total mass of the fine particles in the inland Kanto area.