The carbon cycle is central to the Earth system, being inextricably coupled with climate, the water cycle, nutrient cycles and the production of biomass by photosynthesis on land and in the oceans. In the natural system the balance among carbon in the atmosphere, the land and the ocean is regulated through fluxes between these three main reservoirs. In addition to these natural components, there are the flux contributions to the atmosphere from human activities, namely, fossil fuel burning, cement production, and a range of land management practices.
Understanding the patterns of exchanges of carbon between the atmosphere and the land and the underlying processes associated to them such as CO2 fertilization, changes in climate, and changes to natural disturbance regimes, are critical to improving knowledge of the carbon cycle, its direct and indirect impacts on society. Identifying approaches to mitigate and adapt for the consequences of the anthropogenic disturbance of the carbon cycle is hampered by the uncertain uptake of atmospheric carbon by the terrestrial biosphere, and the response of this uptake to climate change itself.
To achieve such understanding and reduce these uncertainties requires an integrated approach to the carbon cycle which exploits both observations (satellite and in situ) and modelling.
The main objective of the Land surface Carbon Constellation (LCC) project is to demonstrate the synergistic exploitation of satellite observations from active and passive microwave sensors together with optical data for an improved understanding of the terrestrial carbon and water cycles. This will be achieved by:
- adapting a numerical land surface model for its application in a data assimilation framework,
- acquisition and analysis of campaign data sets at Sodankylä (Finland) and Majadas de Tietar (Spain) supporting the development of the model and the data assimilation scheme on the local scale.
The LCC Study started in October 2020 and contributes to ESA’s Carbon Science Cluster, focussing on its land component.