Reanalysis and seasonal forecasts are two major services provided by C3S. They have demonstrated Europe’s leading role in the integration and exploitation of earth system observations for climate monitoring. This is largely due to the use of the best available atmospheric models and data assimilation system, which excel in the integration and prediction of the dynamical variables. While the physical variables in the C3S reanalysis and forecasting systems are consistently modelled and initialized, the treatment of the biogeochemical and human-induced variations is currently not included as part of the modelling. There is an aspiration for C3S to deliver in the future integrated reanalyses across earth system components, which can fully exploit the earth observing system in a consistent manner to provide information on the temporal evolution of atmosphere, land, ocean, sea-ice, and atmospheric chemistry. These integrated Earth System Reanalyses will in turn enable the initialization, verification and calibration of seasonal forecasts of increased number of user relevant climate and environmental variables, such as vegetation indices, air pollution or fires, as to fulfil the demands of downstream users and support the EU Green Deal and UN sustainability goals.

Although there is still substantial ground to cover in the path towards integrated reanalyses and seasonal forecasts of the Earth System, the roadmap for developments is made in incremental steps. CONFESS aims at enhancing the quality of the C3S reanalysis and seasonal forecasts by incremental advances along that roadmap. CONFESS contributions to C3S evolution obey three main principles:

  1. Exploitation of existing observational information and recent model developments according to their readiness level.
  2. Feasible and staged operational implementation.
  3. Impact on the quality of climate services in relation with downstream user needs.


Exploitation of existing observational information and recent…


Feasible and staged operational implementation within CONFESS.


Impact on the quality of climate services in relation with downstream user needs.