The influence of human activities on the distribution of hydroxyl radicals in the troposphere
The influence of human activities on the distribution of hydroxyl radicals in the troposphere
复制标题
人类活动对对流层羟基自由基分布的影响
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
R. Derwent
中科院分区：
文献类型：
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作者：
R. Derwent
在阳光照射下的对流层中发生的涉及甲烷、一氧化碳、氮氧化物、臭氧和水蒸气的自由基反应产生了羟基自由基的分布，这些羟基自由基在清除人类活动排放的许多痕量气体方面发挥着重要作用。英国气象局的二维（高度和纬度）化学传输模式被用来描述微量气体的生命周期和快速光化学，从而计算羟基自由基的分布。据估计，大气层最低层0-12公里处的羟基平均浓度为1.2 x 106分子cm-3（0-24公里处为0.74 x 106分子cm-3）。这一浓度与根据平衡甲基氯仿和14 CO预算所需的OH自由基浓度所作的估计非常一致。二维模型被用来调查可能的未来甲烷浓度，将建立在政府间气候变化专门委员会IS 92 a排放情景，在这段时间内到2050年。由于人类活动的影响，未来OH自由基浓度可能会降低，因此甲烷浓度的增加明显快于排放。因此，人类对对流层氧化能力的干扰会对全球变暖产生重要影响。
The free radical reactions occuring in the sunlit troposphere involving methane, carbon monoxide, oxides of nitrogen, ozone and water vapour, generate a distribution of hydroxyl radicals which play a major role in removing many of the trace gases emitted by human activities. The United Kingdom Meteorological Office two-dimensional (altitude and latitude) chemistry transport model is used to describe the trace gas life cycles and the fast photochemistry and hence to calculate the distribution of hydroxyl radicals. The mean concentration of hydroxyl radicals estimated in the lowest 0-12 km of the atmosphere is 1.2 x 106 molecules cm-3 (0.74 x 106 molecules cm-3 over 0-24 km). This concentration is in good agreement with estimates based on the OH radical concentrations required to balance the budgets of methyl chloroform and 14CO. The two-dimensional model was used to investigate the likely future methane concentrations that would build up in the Intergovernmental Panel on Climate Change IS92a emission scenario over the period up to the year 2050. Because of the decrease in likely future OH radical concentrations due to the influence of human activities, methane concentrations build up significantly faster than emissions. There are therefore important consequences for global warming from human interference in the oxidizing capacity of the troposphere.