許多研究發現，台灣地區近年受到外來輸入的空氣污染物影響與日俱增，然而影響台灣背景大氣之空氣品質甚鉅的來源，包括藉著東北季風而被帶來的大陸性氣流，西南氣流帶來的中南半島生質燃燒的污染排放，以及西太平洋之乾淨海洋性氣團，這三者分別於不同的時間影響著台灣地區的空氣品質，然而其各別的形成機制也大有差異，本研究的主旨即在藉由觀測微量氣體背景大氣濃度之長短期變化趨勢，利用不同物種之大氣生命期的長短，作為比值追查氣團老化程度與旅行距離或時間，並依其物種的特徵變化差異，分析其污染來源的依據，並探討以上不同氣團來源之化學意涵。如先前研究成果中提出，在鹿林山背景測站長期觀測微量氣體中發現，生質燃燒為台灣高山地區空氣污染物之春季高值的主要原因，例如CO與O3等，然而生質燃燒所排放之空氣污染物不僅於此，鹵碳化合物CH3Cl亦為指標性物種之一，同時具有獨特性，本研究中將搭配CO和O3的觀測，作為遠距傳輸事件的評估判定，並應用於研討大氣化學之變化機制。同時，將於墾丁地區評估設立地面背景站，相對於鹿林山之高山特性，獲得台灣地區垂直之剖面化學資訊，此外，且評估於東沙列島設立背景測點，作為監測長程傳輸之中繼站，搭配三個測站的資訊加以討論，鎖定春季中南半島生質燃燒，以及夏季海洋性氣流的交替，探討不同型態之長程輸送所含有的化學特性，並藉觀測的資料來評估台灣地區所受的衝擊影響。 The rapid development in East Asia in the last decade has aroused concerns on the increasing amount of anthropogenic pollutants being injected into this region altering baseline conditions of air quality and climate. Situating on the rim of west Pacific facing east China, Taiwan can serve as an ideal location for monitoring the change in concentration and composition of key species. Due to the lack of systematic background observations in the past in this geophysical region surrounding Taiwan, the impact on the regional air quality and climate brought about by either the continental outflow from China or the biomass burning from Southeast Asia deserve in depth assessments. As a result, a high mountain (2900 m) background station (Lulin atmospheric baseline station; LABS) was established in 2006 in central Taiwan, monitoring ambient concentrations of key pollutants such as CO, CFCs, and O3. In this proposal, green house gases will be added including CO2 and halocarbons (CFCs + HCFCs + HFCs) to better address the climate issues. Biomass burning has been a focus on the agenda of LABS. Carbon monoxide is used as a tracer of burning at LABS. Elevated concentrations of CO and O3 were observed in spring at LABS due to biomass burning in Southeast Asia, which were transported by the prevailing westerlies to East Asia. A new tracer of biomass burning – CH3Cl- will be studied at LABS to observe the possible correlations with CO and O3, and to provide more solid evidence of long range transport. To further facilitate the understanding of the mechanism of long range transport, in this research, we propose to establish two new baseline stations at the south of Taiwan, e.g. Kenting and Dongsha, to investigate the land-sea exchange of air parcels and the effect of long range transport on the air quality of southern Taiwan. Measurements of ozone, CO, and light VOCs, etc. will shed light to the understanding of these intriguing issues. 研究期間：9908 ~ 10007
