Multi-species inversion of CH4, CO and H2 emissions from surface measurements

I. Pison (1, 2) , Philippe Bousquet (1, 3) , F. Chevallier (1, 3) , S. Szopa (1, 4) , D. Hauglustaine (1, 5)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 ICOS-RAMCES - ICOS-RAMCES
3 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
4 CLIM - Modélisation du climat
5 MERMAID - Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics

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 CH 4 , CO and H 2 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, CH 4 and H 2 and concentrations of HCHO and OH were performed for the year 2004, using surface concentration measurements of CO, CH 4 , H 2 and CH 3 CCl 3 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 CH 4 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.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

I. Pison, Philippe Bousquet, F. Chevallier, S. Szopa, D. Hauglustaine. Multi-species inversion of CH4, CO and H2 emissions from surface measurements. Atmospheric Chemistry and Physics, 2009, 9 (14), pp.5281-5297. ⟨10.5194/ACP-9-5281-2009⟩. ⟨hal-02946580⟩