Atmospheric CH4, CO, and CO2
Atmospheric CH4, CO, and CO2
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DOI：
10.1029/jc077i024p04477
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发表时间：
1972-08
影响因子：
--
通讯作者：
S. Wofsy;J. McConnell;M. McElroy
中科院分区：
文献类型：
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作者：
S. Wofsy;J. McConnell;M. McElroy
大气中CH4、CO和CO2的化学成分用一个一维模式来处理，该模式考虑了0-120公里高度区的涡旋扩散效应。甲烷被很好地混合到约20公里处，其混合比在较高的海拔地区稳步下降。一氧化碳在对流层中混合得很好。它的混合比最初在平流层下部减小，在30公里附近达到10−8量级的最小值，在高海拔地区稳定增加。二氧化碳在对流层中混合得很好。它的混合比在平流层有所下降，这种下降反映了人为产生二氧化碳的重要性和平流层扩散的相对较长的时间常数。在120公里附近，CO和CO2的混合比相当。与CH4的氧化相比，燃烧是次要的CO来源。CH4的氧化也提供了平流层H2O和H2的重要来源。CO和CH4的主要汇涉及与OH的反应。二氧化碳在表面和大气中通过光解被去除，程度较小。CO和CH4在大气中的平均停留时间分别为0.3年和7年。
The chemistry of atmospheric CH4, CO, and CO2 is treated with a one-dimensional model incorporating the effects of eddy diffusion in the altitude region of 0–120 km. Methane is well mixed up to about 20 km, and its mixing ratio declines steadily at higher altitudes. Carbon monoxide is well mixed in the troposphere. Its mixing ratio decreases initially in the lower stratosphere, reaches a minimum value of the order of 10−8 near 30 km, and increases steadily at higher elevations. Carbon dioxide is well mixed in the troposphere. Its mixing ratio declines somewhat in the stratosphere, and this decline reflects the importance of anthropogenic production of CO2 and the relatively long time constants for stratospheric diffusion. Mixing ratios of CO and CO2 are comparable near 120 km. Combustion is a minor source of CO in comparison with oxidation of CH4. Oxidation of CH4 also provides a significant source of stratospheric H2O and H2. The principal sinks for CO and CH4 involve reactions with OH. Carbon dioxide is removed at the surface and to a lesser extent in the atmosphere by photolysis. Mean atmospheric residence times for CO and CH4 are 0.3 and 7 years, respectively.