MicroCarb : A CNES Missions for CO2 Concentration Measurements and Flux Monitoring
Breon, Francois-Marie1; Ciais, Philippe1; Philippe, Peylin1; Lyzia, Bensehil1; Buisson, Francois2; Pierangelo, Clémence2; Pradines, Didier2; Pascal, Véronique2; Deniel, Carole2

There is no doubt that increasing concentration of greenhouse gases is causing climate change. The world has already committed to more than two degrees warming since pre-industrial times. There are significant uncertainties, however, linked to the current rate of emissions of both Carbon Dioxide and methane, and the potential feedbacks between the Carbon cycle and climate. To reduce the uncertainties about future climate change, there is a need for a better understanding of the processes that control the fluxes of Carbon and methane. For this purpose a global observation is needed which drives the need for a satellite observation. CNES is committed to this objective and is developing two missions with the aim of monitoring the fluxes of CO2 and CH4.

In this poster, we will present the MicroCarb mission concept. MicroCarb uses a passive radiometer concept to measure the atmospheric column of CO2. As for other missions with a similar objective, it uses the solar radiance reflected by the surface in several spectral bands to estimate the greenhouse gas concentration by the differential absorption method. The originality of the MicroCarb concept is a very compact design using a grating spectrometer, which makes it possible to accommodate the instrument onboard a micro-satellite such as the Myriade platform family.
The MicroCarb mission has now completed phase A analysis. Two industrial studies have been completed and demonstrate the validity of the design. CNES is presently looking for international cooperation for a possible launch before the decade is out. In parallel, data processing tools are being developed to analyse the spectra in terms of CO2 column, and to derive carbon fluxes from the column concentration measurements.