The Copernicus anthropogenic CO2 Monitoring (CO2M) mission – three instruments, three platforms – one goal

As part of the Copernicus component of the EU Space Programme, the European Commission and the European Space Agency (ESA), are expanding the Copernicus Space Infrastructure and are implementing satellite remote measurements to support anthropogenic CO2 emission monitoring. In support of well-informed policy decisions and to assess the effectiveness of strategies for CO2 (and methane (CH4)) emission reduction, uncertainties associated with current anthropogenic emission estimates at national and regional scales need to be improved. Satellite measurements of atmospheric CO2 and CH4, complemented by in-situ measurements and bottom-up inventories will be elaborated in an advanced (inverse) modelling scheme to provide a transparent and consistent quantitative assessment of their emissions and their trends at the scale of megacities, regions, countries, and at global scale. The European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) is responsible for the development of the operational ground segment (with contributions from ESA) and the CO2M system operations during commissioning and the routine phase. This presentation will provide an overview of the mission and instrument development status at ESA and will present first results from the CO2M operational processing system developments ongoing at EUMETSAT. The latter will include first simulations for the dedicated CO2M aerosol, cloud, and NO2 products, as well as from the innovative approach to exploit three retrieval algorithms for greenhouse gases (GHG), i.e. XCH4, XCO2. Here we show how the measurements from the three instruments on-board CO2M (the CO2/NO2 push-broom grating spectrometer (CO2I/NO2I), the Multi Angle Polarimeter (MAP), and the Cloud Imager (CLIM)) are combined into one “hyper-instrument” processing system. This includes the centralized and harmonized provision of auxiliary and a priori information to all level-2 processors and for all satellite platforms, in order to ensure maximum consistency between the parts of the system. The results are based on realistic simulations of orbits for a constellation of three satellite platforms, including one which is continuously following the sun-glint spot instead of looking in the nadir direction. CO2M level-2 products from all platforms of the constellation will be operationally assimilated in the Copernicus GHG Monitoring and Verification Support Capacity (MVS) of the European Commission developed by the Copernicus Atmosphere Monitoring Service (CAMS) at the European Centre for Medium-Range Weather Forecast (ECMWF). The MVS will provide CO2 and Methane emission inventories at a regional, national, and global scale to users and stakeholders. The simultaneous assimilation of the same data-products from multiple platforms requires, next to the centralized “hyper-instrument” processing strategy the stringent intra- and inter-platform instrument calibration with strict requirements on instrument co-registration per platform and between platforms. To achieve and maintain high level of consistency during the full mission lifetime EUMETSAT will use a number of on-board and external calibration reference source, including the sun, the moon, and on-board light sources, as well as stable on-ground reference targets, which will routinely be used for monitoring and re-calibration activities in EUMETSAT.