| 摘要: | 大氣氣膠會折射來自太陽輻射而直接及間接影響地球的輻射平衡，從而抗衡因溫室氣體導致的 全球暖化現象。近年來，區域型高污染及農廢燃燒時期與長程傳輸及偶發的沙塵暴侵襲事件與春季 中南半島大規模生質燃燒等國際污染議題日受重視，這些大氣污染對台灣的空氣品質影響甚鉅，然 而探討不同污染類型的大氣奈米微米氣膠的化學特性，特別是有機物種組成，亦較少同步深入瞭解 微粒數目特性。然而微粒數目濃度與粒徑分布在奈米微粒具有重要訊息，可與氣膠化學組成共同探 討氣膠特性。因此，本研究將以三年時間(105年8月一108年7月），探討在南台灣沿海背景環境(第 一年)(105年8月一 106年7月）、南部都會環境(第二年）（106年8月一 107年7月）及南部郊區環境(第 三年）（107年8月一 108年7月）以光學微粒分析儀(Optical Particle Sizer, OPS)及奈米掃描式微粒電 移動分析儀(NanoScan SMPS Nanoparticle Sizer)的長期同步觀測大氣微粒數目濃度及數目粒徑分 布，並以多功能固/氣分離採樣器(URG，VAPS)及PM1蜂巢管氣膠採樣器(Thermo Scientific, PM1 aerosol sampler with ChemComb cartridge)採集包括酸驗氣體/PM1/PM2.5/PM10 氣膠，再以 MOUDI 及 Nano-MOUDI採集完整的奈米/微米(5nm—18|im)粒徑分階氣膠，長期完整地研究南台灣沿海、都 會及郊區在乾淨大氣時期、區域高污染及長程傳輸污染、南部農廢燃燒時期及春季中南半島大規模 生質燃燒等不同污染傳輸時期之大氣氣膠物種質量濃度、物種粒徑分布、數目濃度及數目粒徑分布 的特性與變異，並以完整的奈米/微米氣膠有機/無機物種濃度變異及不同之有機及無機物種比率， 佐以數目粒徑分布，藉此鑑別老化氣膠(aged aerosol)及新鮮氣膠(fresh aerosol)，以高斯軌跡傳遞係 數模式(GTx)及NOAA HYSPLIT逆軌跡模式，輔以空氣品質模式(Community Multiscale Air Quality, CMAQ)合理解釋可能的主要污染源，瞭解不同大氣環境及大氣污染狀態之各粒徑的氣膠組成生成 濃度差異，並以正矩陣因子法(Positive matrix factorization, PMF)尋找污染源貢獻分配，並探究有機 氣膠物種之間的光化特性關聯、人為污染、海洋飛沫、生質燃燒証據的尋找、判斷大氣氣膠的污染 排放貢獻分配。
Aerosols, which originate from traffic emissions, biomass burning, burning of petroleum fuel as well as from man-made and natural photochemical precursors, are one of the important atmospheric aerosols. Their existence in the atmosphere will refract solar radiation thus directly or indirectly affect the global radiation balance to counterbalance the global warming caused by greenhouse gases. However, the number size distribution, specially nanoparticle size, in the atmospheric particles have not been fully studied and understood with aerosol chemical properties, specially organic substances. Hence, this three-year research will investigate particle number concentration with particle number size distribution, in addition to aerosol characteristics and contribution distribution to aerosol of nano/micron organic compounds, including carboxylic acids, anhydrosugars, sugar alcohols, saccharides with inorganic species during periods of various atmospheric pollutions. The gaseous pollutants, PM1, PM2.5 and PM10 by VAPS sampler and PMi sampler (Thermo Scientific, PM1 aerosol sampler with ChemComb cartridge) will be collected at the same periods. The first year (Aug. 2016 —July 2017) will be devoted to studying the long-term number (applying Optical Particle Sizer and NanoScan SMPS Nanoparticle Sizer) and chemical (applying MOUDI and NanoMOUDI) properties of coastal remote aerosol particles. The second-year research (Aug. 2017 —July 2018) will study the long-term number and chemical properties of Tainan urban aerosol particles. The third-year study (Aug. 2018 —July 2019) will include investigating the number and chemical properties of Tainan suburban aerosol particles. Additionally, the information accumulated during the three-year study period will be analyzed to study the characteristics of nano/micron organic aerosol observed during various PM episodes in order to understand the difference in size distribution for nano/micron organic compounds formed during the background air, clear-air and PM episodes. Furthermore, the use of GTx model, NOAA HYSPLIT, Community Multiscale Air Quality (CMAQ) and Positive matrix factorization (PMF) models during various PM episodes and air qualities will be used to identify the potential sources, calculate their source apportionments, and demonstrate the various pollution sources. |
