The EU-FP7 ERA-CLIM2 project contribution to advancing science and production of Earth-system climate reanalyses

The main goals and activities of the ERA-CLIM2 project are presented, and some of its key results, included the first ensemble of coupled reanalysis of the 20th century, are discussed. ERA-CLIM2 is a European Union Seventh Framework Project started in January 2014 and due to be completed in December 2017. It aimed to produce coupled reanalyses, which are physically consistent data sets describing the evolution of the global atmosphere, ocean, land-surface, cryosphere and the carbon cycle. ERA-CLIM2 has contributed to advancing the capacity for producing state-of-the-art climate reanalyses that extend back to the early 20th century. ERA-CLIM2 has led to the generation of the first European ensemble of coupled ocean, sea-ice, land and atmosphere reanalyses of the 20th century. The project has funded work to rescue and prepare observations, and to advance the data-assimilation systems required to generate operational reanalyses, such as the ones planned by the European Union Copernicus Climate Change Service. This paper summarizes the main goals of the project, discusses some of its main areas of activities, and presents some of its key results