Using a Photochemical Index to Discuss the Ozone Formation and Estimate Hydroxyl Concentration at Downwind Area

作者：Tseng Kuo Hsin; Wang Jia Lin; Kuo Pei Hsuan; Tsuang Ben Jei^*

来源：Aerosol and Air Quality Research, 2009, 9(4): 441-452.

DOI：10.4209/aaqr.2009.05.0026

• Volatile organic compounds
• Photochemical index
• Backward trajectory
• OH concentration

Ozone problem is deteriorating in the mountainous areas in central Taiwan. High level of reactive ozone precursor coming from traffic, industrial activities and vegetation upwind produces ozone episodes in the downwind area. Continuously monitoring of ozone and its precursors with hourly resolution was performed by three photochemical assessment monitoring stations (PAMS) forming a line of upwind, midway and downwind observation. A ratio (ethylbenzene/m, p-xylene) which showed high agreement with ozone concentrations were used as a sensitive photochemical index to represent the degree of photochemical reaction. It was found that both the peaks of the photochemical index and the ozone concentration around noon exhibited a consistent descending order of Jhushan (downwind) > Caotun (midway) > Chonglun (upwind). Furthermore, when coupling photochemical index of the three PAMS with kinetic equations and the trajectory model, OH concentrations were estimated. The results showed that the OH concentration reached the maximum (2.1 x 10(6) - 2.3 x 10(6) molecule/cm(3)) at noon to early afternoon on a daily cycle.

• 出版日期2009-12
• 单位中央民族大学