CORDEX

CORDEX stands for Coordinated Regional Climate Downscaling Experiment. It is an international program under the World Climate Research Programme (WCRP) that coordinates regional climate downscaling efforts to produce high-resolution projections for impact assessment and adaptation planning.

Participating institutions run regional climate models (RCMs) that are driven by boundary conditions from global climate models and are guided by shared experimental designs. The program standardizes domains, protocols, and data formats to enable intercomparison. Typical resolutions range from about 0.22° to 0.44° (roughly 25–50 km).

CORDEX supports regional projections across continents, including Africa, Europe, Asia, the Americas, Oceania, and the Arctic. It combines multi-model ensembles from multiple RCMs and GCMs, facilitating evaluation of biases and uncertainty in simulated climate changes. Outputs are intended for use by researchers, national meteorological services, and policymakers.

Historically, CORDEX began in the late 2000s and has produced simulations aligned with CMIP5 and CMIP6 protocols. Future projects use RCP scenarios from CMIP5-era runs and SSP scenarios from CMIP6-era runs. Data are archived through CORDEX portals and ESGF, with CF-compliant NetCDF formats to support broad accessibility and reuse.

The CORDEX data and products are employed to estimate regional changes in temperature, precipitation, extremes, and drought, aiding regional impact studies and adaptation planning. Ongoing work focuses on expanding regional coverage, reducing downscaling biases, assessing uncertainties, and improving coordination between regional and global climate research communities.