環保專案成果報告查詢系統

專案計畫編號	EPA-91-L105-20-208
經費年度	091
計畫經費	1,500 千元
專案開始日期	2002/03/18
專案結束日期	2002/12/31
專案主持人	王家麟教授
主辦單位	監資處
承辦人
執行單位	國立中央大學化學系
專案分類	環境資訊系統
中文關鍵字	光化學評估監測站
英文關鍵字	photochemical assessment stations,PAMS
協同主持人	詹長權教授
共同主持人
計畫聯絡人
計畫聯絡電話
計畫聯絡信箱

中文摘要	三測站碳氫化合物濃度以崇倫站濃度值最高，呈現出都會區來自汽機車污染源所排放高苯環化合物的特性，草屯與竹山二測站濃度值相近，約為崇倫站濃度的1/3-1/2，草屯站較竹山測站濃度值稍高，竹山與草屯站的化學物質光化程度在臭氧峰時段明顯增高，同時此時段風向、風速明顯對應關係，清楚顯示處在下風的竹山測點在午時量測的空氣團是由境外移入，且空氣團在傳輸路徑上持續光化而產生臭氧，且因無新鮮交通排放注入，造成光化程度升高，與都會區(VOC最大產生區)持續有新鮮交通排放的狀況明顯不同。我們認為以近半年的三站同步運轉已初步確定竹山地區的季節性高臭氧形成的原因為由外傳入，而並非原生。
中文關鍵字	光化學評估監測站

中文摘要

三測站碳氫化合物濃度以崇倫站濃度值最高，呈現出都會區來自汽機車污染源所排放高苯環化合物的特性，草屯與竹山二測站濃度值相近，約為崇倫站濃度的1/3-1/2，草屯站較竹山測站濃度值稍高，竹山與草屯站的化學物質光化程度在臭氧峰時段明顯增高，同時此時段風向、風速明顯對應關係，清楚顯示處在下風的竹山測點在午時量測的空氣團是由境外移入，且空氣團在傳輸路徑上持續光化而產生臭氧，且因無新鮮交通排放注入，造成光化程度升高，與都會區(VOC最大產生區)持續有新鮮交通排放的狀況明顯不同。我們認為以近半年的三站同步運轉已初步確定竹山地區的季節性高臭氧形成的原因為由外傳入，而並非原生。

中文關鍵字

光化學評估監測站

類型	檔名	檔案大小	說明	最新版公開日期
期末報告	0000038090.pdf	30MB	[期末報告]公開完整版	2014/10/31 下午 02:07:46

摘要	The objective of this project sponsored by EPA of Taiwan is to operate and maintain the three photochemical assessment stations (PAMS) deployed in central Taiwan to form a monitoring network. The formation of such a network is essential for investigating the high ozone problem frequently encountered in suburban areas by in-situ monitoring 56 critical non-methane hydrocarbons. The first of the three stations was setup in early 2001 in Taichung city to serve as an up-wind site monitoring elevated ozone precursors typically observed in an urbanized metropolitan area. Approximately a year later, the other two down-wind stations were deployed south east of the Taichung station within Nantou county area, namely the Chouton station and the Chu-shan station, respectively. Simultaneous hourly measurement of 56 target compounds has been made for the three stations since May 2002. A series of procedures and criteria have been developed to quality control the speciation and calibration in terms of accuracy, precision, and long-term stability. We employed the ratio of ethylbenzene versus m, p-xylene in the dataset to indicate the photochemical age of an air parcel. Because the atmospheric lifetime of ethylbenzene is significant longer than that of xylene, and both compounds are likely to be released from an upwind common source, i.e., car exhaust, a larger ratio would translate into a more aged air parcel and hence more depletion in shorter-lived precursors and, therefore, more ozone, and vise versa. As expected, higher ethylbenzene/xylene ratios are indeed accompanied by higher ozone values observed around noon when the prevailing wind is in the northeast direction. It is also found that slower wind speed with the northeastlies often correspond to higher ozone values and higher ethylbenzene/xylene ratios. As a result, based on the striking photochemistry evidence deduced from the PAMS dataset along with ozone and wind data, it is reasonable to postulate that the high ozone level observed at Chushan is the result of photochemical degradation of ozone precursors transported from the northeast upwind areas. Along the transport passage the reactive compounds such as xylenes are subject to greater loss to HO reaction to form ozone than the less reactive compounds, such as ethylbenzene. Concentration difference between ethylbenzene and xylene gradually increase and more ozone is produced as the air mass moves towards the downwind areas such as the Chushan area.
英文關鍵字	photochemical assessment stations,PAMS

摘要

The objective of this project sponsored by EPA of Taiwan is to operate and maintain the three photochemical assessment stations (PAMS) deployed in central Taiwan to form a monitoring network. The formation of such a network is essential for investigating the high ozone problem frequently encountered in suburban areas by in-situ monitoring 56 critical non-methane hydrocarbons. The first of the three stations was setup in early 2001 in Taichung city to serve as an up-wind site monitoring elevated ozone precursors typically observed in an urbanized metropolitan area. Approximately a year later, the other two down-wind stations were deployed south east of the Taichung station within Nantou county area, namely the Chouton station and the Chu-shan station, respectively. Simultaneous hourly measurement of 56 target compounds has been made for the three stations since May 2002. A series of procedures and criteria have been developed to quality control the speciation and calibration in terms of accuracy, precision, and long-term stability. We employed the ratio of ethylbenzene versus m, p-xylene in the dataset to indicate the photochemical age of an air parcel. Because the atmospheric lifetime of ethylbenzene is significant longer than that of xylene, and both compounds are likely to be released from an upwind common source, i.e., car exhaust, a larger ratio would translate into a more aged air parcel and hence more depletion in shorter-lived precursors and, therefore, more ozone, and vise versa. As expected, higher ethylbenzene/xylene ratios are indeed accompanied by higher ozone values observed around noon when the prevailing wind is in the northeast direction. It is also found that slower wind speed with the northeastlies often correspond to higher ozone values and higher ethylbenzene/xylene ratios. As a result, based on the striking photochemistry evidence deduced from the PAMS dataset along with ozone and wind data, it is reasonable to postulate that the high ozone level observed at Chushan is the result of photochemical degradation of ozone precursors transported from the northeast upwind areas. Along the transport passage the reactive compounds such as xylenes are subject to greater loss to HO reaction to form ozone than the less reactive compounds, such as ethylbenzene. Concentration difference between ethylbenzene and xylene gradually increase and more ozone is produced as the air mass moves towards the downwind areas such as the Chushan area.

英文關鍵字

photochemical assessment stations,PAMS