| 摘要: | 中南半島人為活動於每年春(乾)季造成大量生質燃燒事件，其排放之氣膠與雲直接與間接交互作用，影響大氣輻射收支及水循環系統，因此對氣候變遷與人體健康造成重大影響，迄今全球較少科學家深入研究該地區生質燃燒排放之氣膠，故本研究為瞭解生質燃燒區域氣膠對雲凝結核之影響，於該地區定點量測氣膠物理及化學特性。
大氣氣膠之化學成分、混合型態，粒徑大小皆對雲凝結核形成有相當影響，故本研究於泰國安康山測站(19.93˚N，99.05˚E，1,536 m)和台灣鹿林山測站(23.47˚N，120.87˚E，2,862 m)兩地，利用雲凝結核計數器(CCNc)、掃描式電移動度粒徑分析儀(SMPS)、凝結核計數器(CPC)、氣膠微物理及光學儀器定點量測區域氣膠，藉此瞭解泰北生質燃燒區域氣膠之物化特性，並探討氣膠與雲凝結核活化特性之關聯性。觀測時間為2013年2月22日至4月8日。此期間為泰國乾(春)季，此區域生質燃燒事件持續發生，由後推軌跡分析，發現不同空氣源對氣膠物化特性有相當大之變異，分類為3事件。事件A為3月13 - 15日，此期間受境外傳輸及生質燃燒排放源影響，呈現吸濕性較佳和活化率較高之特徵；事件B為3月17 - 20日，此期間受生質燃燒排放影響最嚴重，吸濕性及活化率皆有下降之趨勢；事件C為3月22 - 24日，此期間氣團皆傳輸於邊界層之上，推測受老化作用後吸濕性及活化率降至最低。鹿林山測站位於中南半島及中國下風處，由後推軌跡發現觀測期間氣團經過中國人為污染區域和中南半島生質燃燒源區，推測氣膠物化特性會受影響，分類為3事件。事件I為3月13 - 15日，此期間受中南半島生質燃燒源區影響，氣膠特性呈現低吸濕性及活化率不高之特徵；事件II為3月16 - 18日，此期間氣團來源於中國東北、韓國和日本等地區，推測受人為污染影響；事件III為3月19 - 20日，此期間與事件I類似，但污染程度更為強烈。
總體而言，藉由本研究瞭解不同空氣源之氣膠受傳輸路徑及過程影響，使氣膠物化特性差異甚大，而近生質燃燒區域與源區下風處之量測結果，發現兩地氣膠物化特性之差異。; Indochina artificial activities cause a lot of biomass burning events in each spring (dry) season. The interaction between cloud and aerosol will not only affect radiation budget and water circulation system, but also the climate change and human health. According to above, the interaction must be taken into an issue, but the seldom research in the past literatures. In this study, we will investigate the artificial activities in Indochina, and discuss its interaction and influence.
Because atmospheric aerosols chemical composition, mixed patterns, and particle size can affect the formation of the cloud condensation nuclei, so we used CCN counter, SMPS sizer, CPC, and other aerosol instruments to do in-situ aerosol monitoring at Doi Ang Khang mountain, north of Thailand (19.93˚N，99.05˚E，1536m) and Lulin Mountain, Taiwan (23.47˚N，120.87˚E，2862m), then analyzed biomass burning aerosol properties and aerosol activation properties according to the data from these instruments. The observation time is during 2/22~4/8 2013. This period is Thailand's dry (spring) season, and this area occurred biomass burning events continually. By backward trajectory path analysis, we found that different air source's aerosol properties have considerable variations, and we can classify into three events. The first event, A, is during 3/13~15. In this event, the impact of overseas transport and biomass burning showed the better hygroscopic and high activation ratio. The second event, B, is during 3/17~20, because the affection of biomass burning is serious and the biggest in these three events, so the hygroscopic and activation ratio decreased. The third event, C, is during 3/22~24, the air mass transportation is above the boundary layer. This study speculates that due to aerosol aging, so the hygroscopic and activation ratio are the lowest.
Lulin station located on the downstream of Indochina and China, and we found the trajectory of air mass pass through the artificially pollution area in China, and the biomass burning source regions in Indochina, so we speculated aerosol properties will affect by the trajectory of air mass. In this study, we classified into three events, too. The first event, I, is during 3/13~15. According to the result of the backward trajectory, we found that the aerosol property will be affected by biomass burning source region, showing the low hygroscopic and activation ratio. The second event, II, is during 3/16 ~18. Its air mass transportation is passed through the northeast of China, Korea, Japan and other regions, so the aerosol property will be affected by artificially pollution. The third event, III, is during 3/19~20. This event is similar to event I, but the degree of pollution is stronger.
Overall, the different source region and the influence of transported path will cause the more variations of the aerosol properties, and the result of the downstream test shows different property between these two regions. Combining these into results, the research of Indochina artificial activities will be completed and the influence of Cloud Condensation Nuclei (CCN) will also be clearly in this study. |
