CARRA2 launches: Pan‑Arctic reanalysis at 2.5‑km resolution – dataset from 1985, workshop in June

CARRA2 begins

The Copernicus Climate Change Service (C3S) has launched the next generation of its Arctic reanalysis. CARRA2 covers the entire Arctic and adjacent regions on a 2.5‑km grid. The dataset starts in September 1985 and will be continuously extended to the present.

Coverage, resolution and updates

The high spatial resolution improves the representation of mountains, glaciers, coastal and island features, and mesoscale weather patterns compared with previous pan‑Arctic products. Updates are issued monthly with a latency of less than three months. At the time of publication, 24 years of data are available, delivered in eight three‑year packages; additional vintages will follow progressively.

Data access

CARRA2 is accessible via the Copernicus Climate Data Store (CDS). Data are provided in standardized formats with metadata for use and quality assurance. The staged release facilitates incremental analyses and quality checks until the complete long‑term dataset is available without temporal gaps.

Methodology

Reanalyses combine model forecasts with observations through data assimilation. CARRA2 aims for physical consistency across atmospheric variables, delivering multivariate, spatially and temporally consistent time series for temperature, wind, precipitation, humidity and other parameters. The high resolution requires substantial computing resources and careful preparation of observations, particularly in high‑altitude and coastal locations.

Applications

CARRA2 supports climate research, hydrology, glacier, sea‑ice and permafrost studies, as well as governmental planning. Use cases include trend analyses, investigations of extreme events, calibration and validation of regional climate and hydrological models, and sea‑ice physical simulations. For shipping, coastal protection and hazard assessments, the reanalysis improves boundary conditions for planning and operations.

Workshop in June

A CARRA2 user workshop will take place on 10 June (from 13:00 CEST) and 11 June (until 15:00 CEST) — both in person and via livestream. The programme includes introductions to the data structure and access in the CDS, application examples, guidance on combining CARRA2 with local observation series and satellite data, and Q&A sessions on data quality, parameters and interfaces.