Atmospheric 14CO observations and their use for estimating carbon monoxide removal rates
Atmospheric 14CO observations and their use for estimating carbon monoxide removal rates
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大气 14CO 观测及其用于估算一氧化碳去除率的用途
DOI：
10.1029/94jd01931
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发表时间：
1994
影响因子：
--
通讯作者：
J. Tamaresis
中科院分区：
文献类型：
--
作者：
J. Mak;C. Brenninkmeijer;J. Tamaresis
大气中的{sup 14}CO可以作为全球对流层羟基自由基(OH)浓度的示踪剂，它对许多痕量气体物种的破坏负责。整个地球大气层中的CO是通过N中子俘获反应和热原子氧化产生的。随后，它遵循任何其他CO分子的路径，因此被OH氧化从大气中移除。从同位素信息，也有可能阐明一氧化碳的历史，从其他相同的气团。给出了全球采样活动的结果，确定了这种痕量成分的北半球纬度依赖性和季节极值。作者使用劳伦斯·利弗莫尔国家实验室的二维化学/输运模型来预测CO的时空分布，同时考虑到合理的模拟对于验证大气模型的总体准确性的重要性。在NH中测得的CO纬度梯度与以前南半球活动的结果是一致的，这些结果显示的值低于预测值；在模式模拟中，对流层内的垂直梯度同样被夸大了。讨论了模型输出与观测值之间的差异，约为25%，以及可能产生更多误差的来源。作者还检查了两个半球之间的CO差异，估计在15%到25%之间，NH的水平更高。参考文献27，图6。
Atmospheric {sup 14}CO can be used as a tracer of the global tropospheric hydroxyl radical (OH) concentration, which is responsible for the destruction of many trace gas species. {sup 14}CO is produced throughout the Earth`s atmosphere by a {sup 14}N neutron capture reaction followed by hot atom oxidation. It subsequently follows the pathway of any other CO molecule and is thus removed from the atmosphere by OH oxidation. From the isotopic information it is also possible to elucidate the histories of CO from otherwise identical air masses. Results from global sampling campaigns are presented which establish the northern hemisphere (NH) latitudinal dependence and seasonal extremes of this trace constituent. The authors used the Lawrence Livermore National Laboratory two-dimensional chemistry/transport model to predict {sup 14}CO temporal and spatial distributions, keeping in mind the importance of reasonable simulations for validating the accuracy of atmospheric models in general. The measured {sup 14}CO latitudinal gradient in the NH is consistent with results from previous campaigns in the southern hemisphere, which reveal lower values than predicted; vertical gradients within the troposphere are similarly exaggerated in model simulations. Differences between model output and observations, which are of the order of 25% and the likely sources ofmore » error are discussed. The authors also examine the difference in {sup 14}CO between the hemispheres and estimate this to be between 15 and 25%, with higher levels in the NH. 27 refs., 6 figs.« less