台北市大氣中臭氧時序分佈之特性分析

The Diurnal Variation of Ozone in Taipei City

黎博文(Po-Wen Li) ； 林嘉明(Jia-Ming Lin)

《台灣公共衛生雜誌》 20卷2期 (2001/04) Pp. 131-142

https://doi.org/10.6288/TJPH2001-20-02-07

摘要

目標：本研究旨在觀察及描述整個台北市臭氧濃度的時序變化趨勢，探討其與原發性污染物濃度變化之關係，以及氣溫對臭氧濃度之影響。方法：資料來自台北市環保局所屬六個空氣品質監測站及二個車輛排氣監測站，選取1996年的濃度資料，並配合中央氣象局台北站當年之逐日與逐時氣溫資料，挑出各測站當月臭氧濃度最高的一天，加以統計分析最壞情況下臭氧的24小時時序分佈、季節變化傾向，以及其與Nox和氣溫之線性關係。並且以臭氧的最高濃度除以現行空氣品質標準中小時平均值120ppb，求風險商。結果：依據每日臭氧濃度逐時的變化以及主要波峰出現的時間作分類，台北市每日臭氧濃度變化的型式分為三型：白天型、夜晚型和其他型。白天型的明顯波峰高點出現時間多為午後，波峰持續時間較短但濃度高，最常出現在氣溫較高的6~8月。夜晚型的明顯波峰出現在入夜後，持續時間較長但濃度較低，常發生於6~8月以外的其他月份。其他則不論白天或夜晚，若非均無波峰之出現，就是其波峰並不顯著。當臭氧出現高峰時，Nox的濃度與之有一消一漲的變化趨勢，但只在夜晚型波峰出現時，臭氧和Nox兩者個別的反應速率常數之間呈現較好的線性相關(R2=0.5035)。另外風險商大於１者，約佔白天型的10%左右；而夜晚型的風險商則均小於１。結論：台北市24小時的臭氧濃度變化有兩種較明顯的型態，其中之一波峰出現在早上7時，這種型態比較常在於6月-8月間發現；其他月份常見另外一種型態之變化，其波峰在接近中午時出現。這些型態可能受地理及氣象影響。(台灣衛誌2001；20(2):131－142)

關鍵字

臭氧濃度 ； 臭氧時序分佈 ； 空氣品質監測站

並列摘要

Objectives: This study was aimed at characterizing the diurnal variation patterns of ambient ozone pollution in Taipei Municipal, and its relationship with other primary pollutants as well as to ambient temperature. Methods: We analyzed the 1996 air quality data measured at eight monitoring stations including two situated in areas with heavy traffic, obtained from the Bureau of Environmental Protection, Taipei Municipal Government. The local ambient temperature data was obtained from the Central Weather Bureau. Data analysis, based on the data set at the worse day in each month, characterized the hourly ozone level over a period of 24 hours and also the seasonal trends. The linear relationships between ozone concentration, NOx and temperature were also investigated. The risk quotient of the hourly maximum ozone concentration over the referred air quality standard, an hourly average of 120 ppb, was examined. Results: The results indicated that the 24-hour trends of ozone level were in three patterns: diurnal type, nocturnal type and miscellaneous type. The diurnal type, often occurred during the period from June to August, had an obvious peak with the highest concentration occurring at noon. The nocturnal type, often occurred in the rest of the months, had an apparent peak starting to increase at midnight and gradually reaching the summit by seven o'clock in the morning. The peak of nocturnal-type lasted longer, with relatively lower concentration. The miscellaneous type had patterns with no apparent peak. When the ozone peak appeared, the concentration of NOx did not parallel to that of ozone, although there was a significant correlation between ozone and NOx when ozone trend of nocturnal type occurred (R2 = 0.5035). Approximately 10% of the diurnal type ozone levels had the risk 9uotient greater than one, but none of the nocturnal type. Conclusion: There are two types of 24 hour ozone patterns: one type with the peak level that appears at 7 o'clock in the morning, which occurs more frequently in June through August; the other type with the peak level that appears at noon for the rest of the months. These patterns may have to do with geographic and meteorological influences.(Taiwan J Public Health. 2001 ;20(2):131-142)

並列關鍵字

ozone concentration ； diurnal variation of ozone ； air quality monitoring station.