Organic trace gas measurements by PTR-MS during INDOEX 1999
Organic trace gas measurements by PTR-MS during INDOEX 1999
复制标题
INDOEX 1999 期间通过 PTR-MS 进行有机痕量气体测量
DOI：
10.1029/2001jd000576
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发表时间：
2002
影响因子：
--
通讯作者：
P. Crutzen
中科院分区：
文献类型：
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作者：
A. Wisthaler;A. Hansel;R. Dickerson;P. Crutzen
[1] 在 INDOEX 1999 航行的第 2 航段（3 月 4 日至 3 月 23 日）期间，NOAA 研究船 Ronald H. Brown 上使用质子转移反应质谱仪 (PTR-MS) 对挥发性有机化合物 (VOC) 进行快速响应测量。在本文中，我们首次概述了乙腈、甲醇、丙酮和乙醛在印度洋广阔空间范围（19°N–13°S，67°E–75°E）的分布。冬季季风期间盛行的大气环流将来自印度和中东的污染空气输送到印度洋上空，在热带辐合带（ITCZ）与南半球的原始空气相遇。空气团的化学成分根据其地理来源而变化，这是通过回溯分析追踪的。乙腈（生物质燃烧的选择性示踪剂）与一氧化碳（不完全燃烧的一般示踪剂）的相对丰度反映了生物质燃烧或化石燃料燃烧的特征。这表明印度西部地区存在强烈的生物质燃烧影响，印度东北部地区存在混合污染源，而中东地区则以化石燃料燃烧为主。生物质燃烧影响的空气中富含甲醇（0.70-1.60 ppbv），而所有大陆气团中丙酮（0.80-2.40 ppbv）和乙醛（0.25-0.50 ppbv）含量均升高。污染水平向 ITCZ 方向下降，导致甲醇、丙酮和乙醛的最低浓度分别为 0.50、0.45 和 0.12 ppbv。观察到的丰度表明，在生物质燃烧影响的气团和偏远海洋空气中存在不明来源的丙酮和乙醛。
[1] A proton-transfer-reaction mass spectrometer (PTR-MS) was used for fast-response measurements of volatile organic compounds (VOCs) onboard the NOAA research vessel Ronald H. Brown during leg 2 (4 March–23 March) of the INDOEX 1999 cruise. In this paper, we present a first overview of the distribution of acetonitrile, methanol, acetone, and acetaldehyde over a broad spatial extent of the Indian Ocean (19°N–13°S, 67°E–75°E). The prevailing atmospheric circulation during the winter monsoon transported polluted air from India and the Middle East over the Indian Ocean to meet pristine southern hemispheric air at the intertropical convergence zone (ITCZ). The chemical composition of air parcels changed according to their geographic origin, which was traced by backtrajectory analysis. The relative abundance of acetonitrile, a selective tracer for biomass burning, to that of carbon monoxide, a general tracer for incomplete combustion, reflected the signature of biomass burning or fossil fuel combustion. This indicated a strong biomass burning impact in W-India, mixed pollution sources in NE-India, and the dominance of fossil fuel combustion in the Middle East. Biomass burning impacted air was rich in methanol (0.70–1.60 ppbv), while acetone (0.80–2.40 ppbv) and acetaldehyde (0.25–0.50 ppbv) were elevated in all continental air masses. Pollution levels decreased toward the ITCZ resulting in minima for methanol, acetone, and acetaldehyde of 0.50, 0.45, and 0.12 ppbv, respectively. The observed abundances suggest that there are unidentified sources of acetone and acetaldehyde in biomass burning impacted air masses and in remote marine air.