A14B-03
Attributing Methane and Ozone Radiative Forcing to Changes in Precursor Emissions: Constraints on Atmospheric Oxidation from Multiple Satellite Instruments and Adjoint Sensitivity Analysis
Monday, 14 December 2015: 16:30
3004 (Moscone West)
Thomas W Walker1, Kevin W Bowman2, Junjie Liu3, Zhe Jiang2, Lok N Lamsal4 and Alexander J. Turner5, (1)University of Toronto, Physics, Toronto, ON, Canada, (2)Jet Propulsion Laboratory, Pasadena, CA, United States, (3)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (4)Universities Space Research Association Columbia, Columbia, MD, United States, (5)Harvard University, Cambridge, MA, United States
Abstract:
The direct radiative forcing of both methane and ozone responds to changes in emissions of precursor gases, and in the spatio-temporal structure of those changes. We capture this structure using satellite observations or inversion results from MOPITT (Measurements of Pollution In The Troposphere) CO, OMI (Ozone Monitoring Instrument) NO2, GOSAT (Greenhouse gas Observing SATellite) methane, and TES (Tropospheric Emission Spectrometer) ozone. These constraints are combined in the GEOS-Chem global chemical transport model in a 4D-Var data assimilation framework. This produces an observationally-constrained, chemically self-consistent simulation that provides a description of the spatio-temporal distribution of the hydroxyl radical and other atmospheric oxidants. We use this state as a basis for calculating sensitivities in the GEOS-Chem adjoint model of methane and ozone radiative forcing to spatially-resolved precursor emissions.
