摘 要 在氣膠的吸濕特性研究中，大氣氣膠吸收的水量及粒徑分布的轉移具有很大的意義，因此，了解大氣氣膠隨相對溼度改變在粒徑及含水量上的影響是格外的重要；另外，由於氣膠本身的化學成分也會影響氣膠吸濕特性，因此，即時獲得氣膠的化學成分也是必要的。 本研究成功的建立一套量測大氣乾、濕氣膠粒徑分布系統，此套系統以人工氣膠(NH4)2SO4進行量測，結果顯示乾、濕氣膠粒徑有明顯的差異，而系統量測到的粒徑增長倍數與文獻中的數值相當接近，顯示了本系統的可行性。 本研究在台北市南港區進行大氣氣膠即時量測，發現大氣氣膠的粒徑分部大多是以雙峰型態分布，主要的峰值粒徑在90~100nm及20~30nm，只有少數時間轉變為單峰分布；大氣氣膠體積增長百分比與大氣相對濕度有明顯的相關性存在，但與大氣中硫酸銨濃度的變化相關性較不明顯。 本研究所使用的ISORROPIA模式主要是將吸濕性物質視為硫酸銨進行推估，但實際所量測到的大氣氣膠體積增長百分比與硫酸銨的濃度變化並沒有明顯的關係，此結果說明了實際大氣的吸濕性物種並非完全以硫酸銨為主，而是有其他的吸濕性物質存在，另外，含水量較高個案在粒徑100~500nm的體積增長變化比氣膠含水量低的個案高出許多，此結果顯示大氣氣膠吸濕性物質主要存在於100~500nm之間。 另外，量測的濕氣膠質量濃度與模式所推估的濕氣膠質量濃度有很好的一致性（R2=0.74），但量測值在絕對量上較高，可能來自於SMPS數目濃度高估以及其它成分氣膠存在所影響。 Abstract Atmospheric aerosol water content and diameter shift are very important in hygroscopic research, so find out relative humidity influence aerosol water content and diameter change especially important. Aerosol chemical components also affect hygroscopic characteristic, so get really time aerosol chemical components are necessary. This work successful establish the system in measuring wet and dry particles diameter distribution, and used artificial aerosol (NH4)2SO4 to test the system, result show wet and dry particles have difference in diameter distribution, and measured data growth factor agree with reference value, it mean this system is feasible. The sampling site is at Taipei Nan-Gang region, aerosol diameter distribution display bimodal growth, the modal diameter at 90~100nm and 20~30nm, sometime change one modal distribution. Atmospheric aerosol in volume increasing percentage has well correlation with atmospheric relative humidity, but not well with ammonium sulphate concentration. This work regards ammonium sulphate as main hygroscopic components in apply ISORROPIA model. In fact, aerosol volume increasing percentage has not well correlation with ammonium sulphate concentration. It means ammonium sulphate not full hygroscopic components in atmosphere; there are some hygroscopic components exist at atmosphere. In case study shows higher water content case has more volume increasing percentage than lower water content case at 100~500nm, the result mean hygroscopic components distribution range at 100~500nm. On the side, measuring wet aerosol mass concentration has well concentration with simulating (R2=0.74), but some difference at absolute value. It could be from SMPS higher estimate or others aerosol components influence.
