ESA-CCI Essential Climate Variables in the Climate Data Store

Carlo Buontempo, Chiara Cagnazzo, Joaquin Muñoz Sabater, André Obregón, Iryna Rozum, Freja Vamborg


The Copernicus Climate Change Service (C3S), implemented by ECMWF on behalf of the EU, delivers open and free access to state-of-the-art climate products and information, building upon the latest science. Among different climate data, C3S provides operational services for 22 satellite-based essential climate variables (ECVs). This includes access to derived products, generally in the form of global gridded Climate Data Records (CDRs) through the cloud-based Copernicus Climate Data Store (CDS). A subset of them is delivered in coordination with the European Space Agency Climate Change Initiative (ESA-CCI), where C3S operationalises the ESA-CCI production chains to generate seamless temporal extensions of CDRs. An interactive application displaying variables from ESA-CCI CDRs together with reanalysis variables is under development in the CDS Toolbox. Selected ECVs from ESA-CCI are already routinely used, while others are planned to be used, in the C3S European State of the Climate report and other C3S monitoring activities. They include concentration of greenhouse gases, sea-ice thickness, sea level, sea-surface temperature and ocean colour.

C3S quality control

Together with access to the data, C3S has developed an Evaluation and Quality Control (EQC) framework to assess the technical and scientific quality of different service components, including datasets, applications and tools, with special attention to their value to the users.

The EQC function includes independent scientific assessment of ECV products from satellite observations available through the CDS, including CDRs from ESA-CCI. Those independent assessments are made by scientific experts and complement the evaluations prepared by data providers, by focusing on several aspects such as documentation, data accessibility, usability and dataset maturity.

EQC reports include, for each evaluated dataset: (i) an evaluation of technical characteristics (such as metadata standards, data format, space-time resolution and coverage (an example of coverage is given in the figure); (ii) a section on dataset maturity, focusing on data documentation and uncertainty characterisation and based on a substantial literature review by the evaluators; (iii) a fitness for purpose analysis in the context of specific scientific applications, including dataset homogeneity, its capability to reproduce known climate extremes, and its ability to estimate linear trends.

Data availability plot.
Data availability plot. This plot indicates data availability as a function of latitude and longitude aggregated over the period June 1995 to June 2003 of aerosol optical depth at 550 nm provided by the ATSR2-SU-V4.32 monthly dataset. Grey regions denote pixels for which no data is available.

The fitness for purpose function is generated through the analysis of single CDRs (quality reports of single products) and by looking at consistency across same products from different data sources (quality reports of multi-products).

ESA-CCI and C3S programmes rely on the European scientific community. With complementary objectives, they address the needs of the United Nations Framework Convention on Climate Change for data about climate change and information to support adaptation. Close coordination between the two programmes ensures that, for products available in the CDS, the latest research and development from the ESA-CCI science-driven activities is represented and the production chains are operationalised and transformed into services by C3S.