| 摘要: | 臺灣地處巨大PM2.5負荷的東南亞及東亞區域之間，境外長程傳輸及境內污染的污染成因與貢獻複雜，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，然而，針對都會及非都市區域較缺乏同步氣粒狀污染物與光化機制探究，以瞭解整體區域空氣品質變化的成因，臺灣都會地區因都市污水排放逸散及市區馬路側溝散發與非都市地區農畜排放及自然排放的即時氣狀前驅物NH3其儲量可觀，尤其是處在高NH3排放潛量的南部都會地區及非都市地區，NH3是形成二次光化氣膠極為重要的鹼性前驅物，當各界在嚴重關切空氣品質特別是PM2.5的貢獻來源之時，都會地區及非都市地區不同NH3排放潛量，在二次光化氣膠的生成機制在日間與夜間所扮演的角色在臺灣南部地區尚待進一步深入研究。因此，本研究將以三年時間(108年8月－111年7月)，探討都會及非都市大氣氣膠之氣狀前驅物光化潛勢及氣膠生成老化之數目濃度及化學組成粒徑分布受因研究，在南台灣都會環境(第一年)(108年8月－109年7月)、非都市的農畜區(第二年) (109年8月－110年7月)及南部郊區環境(第三年) (110年8月－111年7月)以sub-ppb級NH3即時測定及光學微粒分析儀及奈米掃描式微粒電移動分析儀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/氣分離採樣器及PM1蜂巢管氣膠採樣器採集包括酸鹼氣體/PM1/PM2.5/PM10氣膠，再以MOUDI及Nano-MOUDI採集完整的奈米/微米粒徑分階氣膠，長期完整地研究南台灣都會及非都市在乾淨大氣時期、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，大氣SOR(硫轉化率)、NOR(氮轉化率)、AMOR(氨轉化率)的氣體/氣膠轉化機制，探知氣狀前驅物光化潛勢，佐以數目粒徑分布，藉此鑑別老化氣膠及新鮮氣膠，以NOAA HYSPLIT逆軌跡模式，輔以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。
Taiwan is located between Southeast Asia and East Asia with huge PM2.5 load. The causes and contributions of long range transport and pollution within the country are complex. In recent years, regional high pollution and agricultural waste combustion period and long range transport and incidental sandstorms have occurred. International pollution issues such as large-scale biomass burning in the Indo-China Peninsula have been highly valued. However, there is a lack of synchronized gaseous pollutants and the photochemical mechanism to understand the causes of changes in the overall regional air quality. The reserves of the immediate gas precursors NH3 in the metropolitan area of Taiwan due to the discharge of urban sewage and the distribution of urban roadside ditch and non-urban areas, and natural discharges are considerable. Especially in the southern metropolitan areas and non-urban areas where high NH3 emission potential is high, NH3 is an extremely important alkaline precursor for the formation of secondary aerosol. At the time of the source, the NH3 emission potential of the metropolitan area and non-urban areas is different. The role played with the night is still to be further studied in southern Taiwan. Therefore, this study will explore the photochemical potential of gas precursors and the ageing and chemical composition of gas-based precursors in metropolitan and non-urban atmospheric aerosols in three years. Urban area (First year) (August 2019-July 2020), non-urban farmland area (second year) (August 2020-July 2021) and southern suburban environment (third year) (August 2021-July 2022) with sub-ppb level NH3 instant measurement and optical particle analyzer (OPS) and nano-scanning particle electro-optical analyzer simultaneous observation of atmospheric particle number concentration, and multi-function gas/aerosol separation sampler and PM1 honeycomb tube aerosol sampler including acid-base gases/PM1/PM2.5/PM10 aerosol, and then the complete nano/micro (5 nm-18 um) particle size aerosol with MOUDI and Nano-MOUDI would be studied in the southern Taiwan metropolis and non-urban in a clean period, regional high pollution and long range transport pollution, southern agricultural waste burning period and large-scale biomass in the Indo-China Peninsula in spring. The characteristics and variations of atmospheric aerosol species mass concentration, species particle size distribution, number concentration and number particle size distribution during different pollution transmission periods, and the variation of the concentration of nano/micro organic/inorganic species and their differences ratio of organic and inorganic species, atmospheric SOR (sulfur conversion), NOR (nitrogen conversion), AMOR (ammonia conversion) gas/aerosol conversion mechanism, the photochemical potential of gas precursors, with particle number size distribution would identify aged aerosol and fresh aerosol, with NOAA HYSPLIT trajectory mode, supplemented by Community Multiscale Air Quality (CMAQ) is to explain possible major sources of pollution, understand the difference in the composition of the aerosol of each particle size in the atmospheric environment and the air pollution state, and the positive matrix factorization (PMF) method would find the contribution distribution of the pollution source, and explore the correlation of the photochemical characteristics between the organic aerosol species, man-made pollution, biomass burning, and the distribution of pollutant emissions contribution to atmospheric aerosols. |
