Olmo et al. (2026) Robustness of Euro-Mediterranean Synoptic Circulation Types and Sensitivity to Member Selection in CMIP6 Models

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-01-15
• Authors: Matías Ezequiel Olmo, Pep Cos, Diego Campos, Ángel G. Muñoz, Margarida Samso, Albert Soret, Francisco Doblas-Reyes
• DOI: 10.1175/jcli-d-24-0545.1

Research Groups

Institutions contributing to the Coupled Model Intercomparison Project phase 6 (CMIP6), including those developing models such as EC-Earth3 and MIROC6.

Short Summary

This study assesses the influence of internal variability on atmospheric circulation type (CT) classifications in the Euro-Mediterranean region using 262 CMIP6 simulations, finding significant spread among individual model members but superior performance from the multimember ensemble mean, highlighting individual member selection as a critical uncertainty source.

Objective

• To assess the influence of internal variability (IV) on a classification of atmospheric circulation types (CTs) in the Euro-Mediterranean (EM) region using CMIP6 global climate model simulations.

Study Configuration

• Spatial Scale: Euro-Mediterranean (EM) region
• Temporal Scale: 1950–2014 (reference period for reanalysis); daily classification for 262 simulations

Methodology and Data

• Models used: Eight global climate models (GCMs) from the Coupled Model Intercomparison Project phase 6 (CMIP6) historical experiment (e.g., EC-Earth3, MIROC6).
• Data sources: 262 simulations from CMIP6 historical experiment; reanalysis-based daily classification of CTs (as reference) for 1950–2014.

Main Results

• The seasonality of atmospheric circulation types (CTs) is generally well captured by the models.
• Considerable spread exists among individual model members across different evaluated attributes of CTs.
• CTs typical of transition seasons and those related to rainfall are more challenging for models to reproduce accurately.
• The multimember ensemble mean demonstrates notably better performance than individual members in capturing CT variability.
• EC-Earth3 and MIROC6 simulations presented the best performances among the evaluated models.
• The selection of individual ensemble members is a non-negligible factor and an additional source of uncertainty when analyzing CT classifications and assessing long-term surface trends at the regional scale, particularly in hotspot regions like the Euro-Mediterranean.

Contributions

• Quantifies the impact of internal variability on atmospheric circulation type classifications using a large ensemble of CMIP6 models.
• Highlights the significant spread among individual CMIP6 ensemble members and the superior performance of the multimember ensemble mean in reproducing CT variability.
• Emphasizes the critical importance of considering individual ensemble member selection as a source of uncertainty when generating tailored regional climate information, especially for vulnerable regions.

Funding

Not specified in the abstract.

Citation

@article{Olmo2026Robustness,
  author = {Olmo, Matías Ezequiel and Cos, Pep and Campos, Diego and Muñoz, Ángel G. and Samso, Margarida and Soret, Albert and Doblas-Reyes, Francisco},
  title = {Robustness of Euro-Mediterranean Synoptic Circulation Types and Sensitivity to Member Selection in CMIP6 Models},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-24-0545.1},
  url = {https://doi.org/10.1175/jcli-d-24-0545.1}
}