Biogenic Sources of Atmospheric Acetone and Other Carbonyls

大气丙酮和其他羰基化合物的生物来源

• 批准号: 9805191
• 负责人: Richard Fall
• 金额: $ 28万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9805191&HistoricalAwards=false
• 关键词: Biogenic; Sources; Atmospheric; Acetone; Other

This proposal addresses biosphere-atmosphere exchange of acetone, a volatile organic compound (VOC) that enters the Earth's atmosphere and is important in odd hydrogen radical (HOx) and background ozone formation in the upper troposphere and lower stratosphere. Acetone photochemistry also results in the formation of peroxyacetylnitrate, with resultant sequestering and transport of odd nitrogen (NOx) equivalents. While it is clear that these acetone-related processes affect the oxidative capacity of the atmosphere, there are significant uncertainties in the global acetone budget, estimated as 40-60 Tg yr-1, especially in the rates of biogenic acetone emission and the mechanisms of biogenic acetone formation. The major goal of the proposed work is to establish the underlying mechanisms of formation of acetone and methyl ethyl ketone in plant tissues, and to characterize the controls over their release from plant surfaces. We also want to determine if certain crops have been overlooked as major sources of carbonyl emissions. The project will include both laboratory experiments and field verification via examination of data sets from collaborative field experiments organized by scientists at the National Center for Atmospheric Research (NCAR). Planned laboratory, greenhouse and field experiments should produce much-needed data sets on biogenic carbonyl fluxes from vegetation, and should contribute to the development of an integrated plant VOC emission model to explain the partitioning of plant carbon into volatiles. This modeling could be significant, because plants often emit 1-8% of fixed CO2 as VOCs, and an important aspect of biosphere-atmosphere exchange is to understand why and how plants commit resources to volatile secondary compound production. Such information is vital if we are to predict changes that will occur in the Earth's atmosphere as the result of human impacts of the biosphere.

该提案涉及丙酮的生物圈-大气交换，丙酮是一种挥发性有机化合物，进入地球大气层，在对流层上部和平流层下部的奇氢自由基（HOx）和背景臭氧形成中很重要。丙酮光化学也导致过氧乙酰硝酸盐的形成，从而螯合和运输奇数氮（NOx）当量。虽然很明显，这些丙酮相关的过程影响大气的氧化能力，有重大的不确定性，在全球丙酮预算，估计为40-60 Tg年-1，特别是在生物丙酮排放的速率和生物丙酮形成的机制。 拟议的工作的主要目标是建立丙酮和甲基乙基酮在植物组织中形成的潜在机制，并表征其从植物表面释放的控制。我们还想确定某些作物是否被忽视为羰基排放的主要来源。该项目将包括实验室实验和通过检查由国家大气研究中心（NCAR）的科学家组织的合作现场实验的数据集进行现场验证。 计划进行的实验室、温室和实地实验应产生急需的关于植被中生物源羰基通量的数据集，并应有助于开发一个综合的植物挥发性有机化合物排放模型，以解释植物碳在挥发物中的分配。这种建模可能是重要的，因为植物通常排放1-8%的固定CO2作为VOC，生物圈-大气交换的一个重要方面是了解植物为什么以及如何将资源用于挥发性次生化合物的生产。如果我们要预测地球大气层由于人类对生物圈的影响而发生的变化，这种信息是至关重要的。