Coordinated Regional Downscaling Experiment - CORDEX

Summary Description

CORDEX provides downscaled projections of variables such as temperature, precipitation, and wind for multiple continental domains, enhancing the usability of global model data for regional infrastructure planning.
It is widely used for hydropower, energy demand forecasting, and climate impact analysis in electricity system planning. The CORDEX (Coordinated Regional Downscaling Experiment) initiative, under the World Climate Research Programme (WCRP), provides regional climate projections derived from downscaling CMIP5 and CMIP6 global climate model outputs.
Its goal is to produce high-resolution regional climate data to support impact studies, risk assessments, and adaptation planning.

Key features include:

  • High-resolution regional grids (~0.11° to 0.44°)
  • Bias-corrected or raw outputs for different regions
  • Multi-model ensembles for robust uncertainty analysis

CORDEX Domains

Example CORDEX domain map (source: Giorgi et al., 2009)

Dataset Characteristics

  • Current version: CMIP6-driven CORDEX (2020–present)
  • Temporal coverage: Historical (1950–2014) and future (2015–2100)
  • Temporal resolution: Daily, monthly, and annual
  • Spatial coverage: Multiple continental domains (e.g., EUR-11, NA-22, AFR-44)
  • Spatial resolution: 0.11° (~12 km), 0.22° (~25 km), 0.44° (~50 km)
  • Data type: Gridded NetCDF (regional model output)
  • Web references:
    Official CORDEX Portal
    CORDEX Data on ESGF
  • Reference publications:
    See references below

Strengths and Limitations

Key Strengths of CORDEX

Strength Description
High Spatial Resolution Resolves regional topography and local climate patterns better than GCMs.
Multi-Model Ensembles Uses multiple regional climate models (RCMs) and multiple GCM drivers.
Regional Relevance Provides climate projections tailored to continental or national domains.
Supports Impact Studies Directly supports hydropower, urban, and energy risk assessments.

Key Limitations of CORDEX

Limitation Description
Domain-limited Coverage Data is only available for specific continental domains, not truly global.
Boundary Dependence Quality depends on the driving GCM and boundary conditions.
Large Data Volume High-resolution and multi-member ensembles require significant storage and processing.
Biases Remain Downscaling reduces, but does not eliminate, GCM biases.

Expert Guidance

  • Use bias-corrected CORDEX data for hydropower and temperature-dependent demand studies.
  • Combine multiple RCMs and GCM drivers to represent uncertainty in electricity planning.
  • Downscaled wind and temperature data are particularly useful for renewable integration and load projections.
  • Link CORDEX projections to vulnerability and risk assessments for grid infrastructure and generation planning.

Example Applications

Links to Electricity Sector Activities:

  • Electricity System Planning – Improved regional demand and renewable resource forecasting
  • Operations Planning – Assess regional hydropower inflows and extreme event risks
  • Infrastructure Planning and Asset Management – Evaluate sub-national exposure to heatwaves, droughts, and storms
  • Assurance and Reporting – Support climate risk disclosure for regional utilities

Available Variables in CORDEX

Click on variable groups to uncollapse

Daily and monthly mean near-surface temperature.

Total precipitation, essential for hydropower, flood, and drought assessment.

Supports wind energy studies and storm risk assessment.

Includes humidity, radiation, soil moisture, and evaporation in some domains.

Data Access

References