The 2011 European Commission report on the Global Monitoring of Environment and Security (GMES) climate service articulated European ambition for the GMES Climate Service to provide information products which are of climate quality. Together, these products will meet the first three goals of the Global Climate Observing System (GCOS):

For climate and climate change monitoring, space-based observations provide a key source of data at global scales of the Earth’s environment, climate change, and the provision of Climate services. An identification of the key observables has been undertaken by GCOS in defining Essential Climate Variables (ECV), such as air temperature, precipitation, carbon dioxide, sea level, sea surface temperature, snow cover. The GMES services in the Land, Marine and Atmosphere domain include within their product portfolios a wide range of parameters which are related to these ECVs, and may contribute to their determination and generation. More importantly, space based observations processed by the GMES services will contribute to climate change analyses if the continuity of the underlying measured physical parameters can be reconciled with previously existing data records.

The purpose of this CORE-CLIMAX project is to coordinate the identification of available physical measurements, which can be reconciled with previously existing data records, to form long time series. As such this project will help to substantiate how GMES observations and products can contribute to climate change analyses, by establishing the extent to which GMES observations complement existing Climate Data Records. The project will identify the capability of on-going activities and contribute to the formulation of the GMES climate service theme and lay the observational basis for service activities.

Since reanalyses are important for improving and synthesizing historical climate records, and for providing regional detail in a global context necessary for policy development and implementation, CORE-CLIMAX will identify the integration of ECVs into the reanalysis chain by proposing a feedback mechanism ensuring that the results of the re-analysis process get appropriately reflected into updates of the ECVs. Together with inter-comparing different reanalyses, CORE-CLIMAX will contribute to establish a European truly coupled gridded re-analysis which incorporates full exchanges and interactions between atmosphere, ocean, land, including the hydrological cycle. More specific objectives of the CORE-CLIMAX project are listed here