Multi-species inversion of CH4, CO and H2 emissions from surface measurements Laboratoire des Sciences du Climat et de l'Environnement, UMR1572, CEA-CNRS-UVSQ, IPSL, Gif-sur-Yvette, France
Received: 04 Sep 2008 – Published in Atmos. Chem. Phys. Discuss.: 11 Dec 2008 – Published: 29 Jul 2009Abstract. In order to study the spatial and temporal variations of the emissions of
greenhouse gases and of their precursors, we developed a data assimilation
system and applied it to infer emissions of CH4, CO and H2 for one year.
It is based on an atmospheric chemical transport model and on a simplified
scheme for the oxidation chain of hydrocarbons, including methane, formaldehyde,
carbon monoxide and molecular hydrogen together with methyl chloroform. The
methodology is exposed and a first attempt at evaluating the inverted fluxes
is made. Inversions of the emission fluxes of CO, CH4 and H2 and
concentrations of HCHO and OH were performed for the year 2004, using
surface concentration measurements of CO, CH4, H2 and CH3CCl3
as constraints. Independent data from ship and aircraft measurements and
satellite retrievals are used to evaluate the results. The total emitted
mass of CO is 30% higher after the inversion, due to increased fluxes by
up to 35% in the Northern Hemisphere. The spatial distribution of emissions
of CH4 is modified by a decrease of fluxes in boreal areas up to 60%. The
comparison between mono- and multi-species inversions shows that the results
are close at a global scale but may significantly differ at a regional scale
because of the interactions between the various tracers during the inversion.
Citation: Pison, I., Bousquet, P., Chevallier, F., Szopa, S., and Hauglustaine, D.: Multi-species inversion of CH4, CO and H2 emissions from surface measurements, Atmos. Chem. Phys., 9, 5281-5297, doi:10.5194/acp-9-5281-2009, 2009.