Non-linear chemistry of methane. Final report, December 1990-September 1993

Technical Report · Sat Apr 01 04:00:00 EST 1995

OSTI ID:212369

Madronich, S; Hess, P; Fischer, C

The tropospheric chemistry of methane (CH4) is complex and depends non-linearly on emission fluxes of CH4 and other tropospheric constituents such as nitrogen oxides (NOx) and carbon monoxide (CO). Concern exists that increased CH4 emissions will reduce hydroxyl (OH) radicals (which determine the self-cleaning or oxidizing capacity of the troposphere) and increase the formation of noxious oxidants (especially ozone, O3). The authors have explored the steady-state solution phase space in a zero-dimensional model, and found four qualitatively different regimes: (1) for low CH4 and low NOx, OH is high and O3 is low; (2) for high CH4 and low NOx, OH is reduced while O3 is high; (3) for low CH4 and high NOx, both OH and O3 are suppressed; and (4) for high CH4 and high NOx, both OH and O3 levels are high. The high NOx solutions can exhibit multiple solutions and oscillations. The emission fluxes at which transitions occur from one regime to another were derived.

• Research Organization: National Center for Atmospheric Research, Boulder, CO (United States)
• OSTI ID: 212369
• Report Number(s): PB--96-143664/XAB; CNN: Contract GRI-5090-254-1993
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CHEMISTRY
METHANE
NITROGEN OXIDES
OZONE
PROGRESS REPORT
TROPOSPHERE