Atmospheric CH/sub 4/, CO, and CO/sub 2/

Journal Article · Sun Aug 20 04:00:00 EDT 1972 · J. Geophys. Res.; (United States)

OSTI ID:5485685

Wafsy, S C; McConnell, J C; McElroy, M B

The chemistry of atmospheric CH/sub 4/, CO, and CO/sub 2/ 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/sup -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 CO/sub 2/ and the relatively long time constants for stratospheric diffusion. Mixing ratios of CO and CO/sub 2/ are comparable near 120 km. Combustion is a minor source of CO in comparison with oxidation of CH/sub 4/. Oxidation of CH/sub 4/ also provides a significant source of stratospheric H/sub 2/O and H/sub 2/. The principal sinks for CO and CH/sub 4/ 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 CH/sub 4/ are 0.3 and 7 years, respectively.

• Research Organization: Smithsonian Astrophysical Observatory, Cambridge, MA
• OSTI ID: 5485685
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 77:24; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
ALKANES
ATMOSPHERIC CHEMISTRY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
DIFFUSION
EARTH ATMOSPHERE
HYDROCARBONS
METHANE
MIXING
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLLUTION
POLLUTION SOURCES
SINKS
STRATOSPHERE
TROPOSPHERE