Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/45503
標題: Assessing the Relationship between Air Mass Age and Summer Ozone Episodes Based on Photochemical Indices
作者: Tseng, K.H.
莊秉潔
Wang, J.L.
Cheng, M.T.
Tsuang, B.J.
鄭曼婷
關鍵字: Ozone
Aerosol
Aging
Backward trajectory
Conversion ratio
Photochemical index
plume trajectory model
urban area
source/receptor relationship
secondary aerosols
primary pollutants
central taiwan
aerodynamic
roughness
particulate nitrate
flux measurements
dry deposition
期刊/報告no:: Aerosol and Air Quality Research, Volume 9, Issue 2, Page(s) 149-171.
摘要: Although pollutant sources are usually in urban and industrialized areas, poor air quality is frequently encountered in downwind rural areas. This study utilized a tethered balloon to measure the pollutant concentrations in a downwind side (Caotun) of the Taichung Basin during the summer of 2002. Furthermore, an annular denuder system ( ADS) was used to measure PM(2.5) and gaseous pollutant concentrations. Concentrations of 55 VOCs species were measured continuously by a network of photochemical assessment monitoring stations in central Taiwan. This study discusses the correlation between the ozone concentration and the routes of an air mass during ozone episodes. Backward trajectory, ratio of particulate matter and photochemical indices were used to examine the aging degree of an air mass. During ozone episodes, the trajectory distribution had a clear sea-land breeze mechanism with a relatively slow wind speed, and the air mass primarily entered through the western coastal industrial area. Analytical results demonstrate that daytime ozone concentrations accompany HNO(3) concentrations by photochemical reactions and depend on the previous night's HNO(2) concentration. The sulfur and nitrogen conversion ratios, and the photochemical indices (ethylbenzene/ m,p-xylene, n-pentane/t-2-pentene and NO(2)/NO) increased with the ozone concentration. The downwind photochemical indices were strongly correlated with ozone concentration and were higher than those upwind. These phenomena indicate that the air mass during ozone episodes belongs to the "more aged" category.
URI: http://hdl.handle.net/11455/45503
ISSN: 1680-8584
Appears in Collections:環境工程學系所

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.