EPA-92-U1L1-02-103

092

2,060 千元

2003/03/06

2003/12/31

李崇德

監資處

國立中央大學環境工程研究所

環境資訊系統

大陸沙塵暴,生質燃燒,氣塊軌跡

Asian Dust Storm,biomass burning,air trajectory

林能暉

黃希爾

0925876606

hehuang@ev.ncu.edu.tw

本計畫配合環保署發布的大陸沙塵影響期間前後在陽明山進行PM10和PM2.5質量濃度採樣及氣膠微粒成分分析，總計在沙塵期間各完成26個PM10和PM2.5有效樣本；在雲、霧水及降水的密集觀測方面共收集到196個樣本。本計畫也對東南亞生質燃燒的懸浮微粒、雲、霧水及降水作了一次觀測研究，以及配合環保署對於大甲媽祖出巡空氣品質影響評估作了一次觀測。此外，在非沙塵期間又分別完成了14、16、16個TSP、PM10與PM2.5有效樣本。 今年沙塵影響程度較小，PM10濃度不高，但PM2.5與PM10變化趨勢相當一致，且PM2.5佔PM10比例相當高。在氣膠成分方面，PM2.5於沙塵影響期間固然以硫元素佔大部分，PM2.5-10則仍以矽、鈣塵土元素和硫為主，顯示沙塵特徵還是存在。當氣流軌跡來自沙塵源區且傳輸高度較高，則沙塵特徵明顯，反之，當氣流軌跡經過大陸沿岸，且傳輸高度低，則含硫成分明顯。此外，沙塵期間微粒碳成分低。 從過去的雲水觀測中可發現當SO42-較多時，pH值?較低，當沙塵來時，pH值?受Ca2+影響，中和掉H+離子使得pH值升高。但在本年度的觀測，沙塵雲水不若往年有Ca2+會增長一倍的現象，反而是有來自華南污染物如硫酸等，使得雲水較酸。去年雲水中的離子多以Cl-、Na+為主，並未出現如今年SO42-、NH4+及NO3-增高的現象， 鹿林山採樣期間的氣流軌跡線來自東南亞生質燃燒的傳輸時，微粒質量濃度明顯較高於來自太平洋海洋傳輸。前者帶來含鉀成分微粒，硫酸根離子與碳成分也都較高。 在媽祖出鑾與回鑾的期時間，微粒質量濃度明顯較高，PM2.5與PM10微粒濃度變化相當一致，顯示兩者來自相同污染源。出鑾期間硝酸根離子濃度增加許多，回鑾期間則是硝酸根離子和鉀離子濃度顯著增加。

大陸沙塵暴,生質燃燒,氣塊軌跡

0000024413.pdf

26MB

[期末報告]公開完整版

2004/2/1 上午 12:00:00

This study characterized aerosol and cloud water collected at Young-Min Mountain during China’s dust affected periods. Analyses of 26 effective PM10 and PM2.5 samples and 196 cloud-and-fog water are accomplished in this operation. Meanwhile, aerosol and cloud-and-fog water from the Southeast Asia were also investigated in an intensive study at Lu-Ling Mountain. The effect on air quality resulted from worshipping on Da-Chia Goddess during her inspection tour was assessed. In addition, 14, 16, and 16 effective TSP、PM10 and PM2.5 samples were collected during non-dust periods. The influence of China’s dust is less severe this year. The concentration of PM10 is not high, however, PM2.5 fraction in PM10 is relatively high and has a consistent variation with PM10. In aerosol composition, sulfur is predominant in PM2.5; in contrast, silicon, calcium, and sulfur are major elements in PM2.5-10. The elemental content of PM2.5-10 shows the evidence of dust arrival. Meanwhile, trajectory analysis verifies that dust characteristics of aerosol is evident for air masses originated from dust storm region and transported high. In contrast, aerosol sulfur is significant for air masses pass China’s coastal area and transported low. Also, aerosol carbon is low during dust periods. Previous observations on cloud-and-fog water showed that high SO42- was associated with low pH value. The pH value, however, is lifted by the increase of Ca2+ for its ability in neutralizing H+ ions. In contrast, the Ca2+ in the cloud water of the dust flow was not increased as expected and the airflow from the South China transported sulfate to make cloud water more sour. The cloud water was predominantly with Cl- and Na+ last year, whereas major ions were SO42-, NH4+, and NO3- this year. For air trajectories from the Southeast Asia with biomass burning, aerosol concentration at Lu-Ling Mountain is significantly higher than that from the Pacific Ocean. The airflow from biomass burning was transported with aerosol potassium plus higher sulfate and carbons.

Asian Dust Storm,biomass burning,air trajectory