Organic particulate material levels in the atmosphere: Conditions favoring sensitivity to varying relative humidity and temperature
Organic particulate material levels in the atmosphere: Conditions favoring sensitivity to varying relative humidity and temperature
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DOI：
10.1073/pnas.1001043107
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发表时间：
2010-04
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影响因子：
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通讯作者：
J. Pankow
中科院分区：
文献类型：
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作者：
J. Pankow
这项研究考察了大气有机颗粒物(Mo，μg m-3)预测水平的敏感性，因为这些水平可能会受到相对湿度和温度变化的影响。在给定的体系中，对于每个分配化合物，Fg和Fp代表气态和颗粒分数(Fg+Fp=1)。随着在颗粒相(FP→1)中越来越多地发现对钼有显著贡献的化合物，钼水平的灵敏度变得降低。因此，尽管随着钼水平的增加可以遇到灵敏度的局部极大值，因为随着每个FP→1的钼水平增加，那么增加的钼水平通常倾向于降低钼水平对相对湿度和温度变化的敏感性。旨在阐明相对湿度和温度对钼水平影响的潜在程度的实验必须在与环境大气相关的钼水平上进行：重要分配化合物的FP值不得高于与环境相关的值。钼水平较低(例如1-2μg m-3)和/或由未老化的次生有机气溶胶组成的系统最有可能对相对湿度和温度的变化表现出敏感性。在上述方面对两个已发表的小室研究的结果进行了检验：[Warren B，et al.(2009)Atmos环境43：1789-1795]和[Prisle NL，et al.(2010)地球物理研究报告37：L01802]。
This study examines the sensitivity in predicted levels of atmospheric organic particulate matter (Mo, μg m-3) as those levels may potentially be affected by changes in relative humidity and temperature. In a given system, for each partitioning compound, fg and fp represent the gaseous and particulate fractions (fg + fp = 1). Sensitivity in the Mo levels becomes dampened as the compounds contributing significantly to Mo are increasingly found in the particle phase (fp → 1). Thus, although local maxima in sensitivity can be encountered as Mo levels increase, because as Mo increases each fp → 1, then increasing Mo levels generally tend to reduce sensitivity in Mo levels to changes in relative humidity and temperature. Experiments designed to elucidate the potential magnitudes of the effects of relative humidity and temperature on Mo levels must be carried out at Mo levels that are relevant for the ambient atmosphere: The fp values for the important partitioning compounds must not be elevated above ambient-relevant values. Systems in which Mo levels are low (e.g., 1–2 μg m-3) and/or composed of unaged secondary organic aerosol are the ones most likely to show sensitivity to changing relative humidity and temperature. Results from two published chamber studies are examined in the above regard: [Warren B, et al. (2009) Atmos Environ 43:1789–1795] and [Prisle NL, et al. (2010) Geophys Res Lett 37:L01802].