Formation of atmospheric particles from organic acids produced by forests
Formation of atmospheric particles from organic acids produced by forests
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DOI：
10.1038/27179
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发表时间：
1998-10-15
期刊：
影响因子：
64.8
通讯作者：
Stephanou, EG
中科院分区：
文献类型：
--
作者：
Kavouras, IG;Mihalopoulos, N;Stephanou, EG
气溶胶在大气中的形成是一个需要了解的重要过程，因为这些颗粒可能作为云凝结核，造成“云气候”效应（1），并可能对当地的健康有害。大气气溶胶和云凝结核的数量浓度主要由有机气溶胶的贡献。大部分有机气溶胶是由大气气体转化为颗粒物形成的，植物排放的常见和广泛的非甲烷碳氢化合物已被研究为可能的气溶胶。但是，到目前为止，还缺乏强有力的证据来证明生物碳氢化合物排放和有机气溶胶形成之间存在定量联系。在这里，我们提出了测量的气体和颗粒物的大气物种从森林地区表明，一些碳氢化合物（例如，萜烯）由植被排放的光氧化为有机酸（例如，pinonic酸），冷凝形成有机气溶胶。因此，森林通过产生大量的有机气溶胶，对气候（通过云凝结核的形成）和异质大气化学过程都具有相当大的意义。
Aerosol formation in the atmosphere is an important process to understand, in that such particles may act as the cloud condensation nuclei responsible for the 'cloud-climate' effect(1), and could locally be hazardous to health. The number-concentration of total atmospheric aerosols and cloud condensation nuclei is largely contributed by organic aerosols'. Much of the organic aerosol is formed from atmospheric gas-to-particle conversion, and the common and widespread non-methane hydrocarbons emitted by vegetation have been investigated as possible precursors'. But strong evidence for a quantitative link between biogenic hydrocarbon emission and organic aerosol formation has so far been lacking. Here we present measurements of gaseous and particulate atmospheric species from a forested area to show that some hydrocarbons (for example, terpenes) emitted by vegetation are photo-oxidized to organic acids (for example, pinonic acids), which condense to form organic aerosols. Thus the forests, through their production of large quantities of organic aerosols, could be of considerable significance both for climate (through cloud-condensation-nuclei formation) and for heterogeneous atmospheric chemical processes.