Climatic impacts of a warmer mediterranean sea simulated by the fully coupled community earth system model, version 2 (CESM2)
Toker, E., Ilicak, M., Danabasoglu, G., Sen, O. L.. (2026). Climatic impacts of a warmer mediterranean sea simulated by the fully coupled community earth system model, version 2 (CESM2). Journal of Climate, doi:https://doi.org/10.1175/jcli-d-25-0540.1
| Title | Climatic impacts of a warmer mediterranean sea simulated by the fully coupled community earth system model, version 2 (CESM2) |
|---|---|
| Genre | Article |
| Author(s) | E. Toker, M. Ilicak, Gokhan Danabasoglu, O. L. Sen |
| Abstract | This study presents a set of process-oriented sensitivity experiments using the state-of-the-art fully coupled Community Earth System Model, version 2 (CESM2), for the first time to isolate the role of Mediterranean sea surface temperature (MedSST) anomalies from regional to global scales. Ten-member ensembles of historical simulations (Control) and two Mediterranean Pacemaker experiments [Mediterranean Pacemaker (MedP) and MedP +3°C (MedP3)] are performed for the 1980–2014 period. MedP aims to achieve an accurate representation of MedSST evolution by applying bias corrections to the model-simulated fields, while MedP3 introduces a +3°C perturbation to MedP as an idealized experiment to explore the sensitivity of the climate to substantially warmer MedSSTs. The impacts of the bias correction are evaluated by comparing MedP and Control with observational-based data, while the climatic impacts of a warmer Mediterranean are assessed by comparing MedP3 with MedP. MedP improves the representation of surface temperatures over large parts of the Euro-Mediterranean region. Relatedly, there are not only improvements in precipitation patterns over Anatolia, the Balkans, and Gibraltar but also degradations in central Europe and the southern Mediterranean basin. In MedP3, warmer MedSSTs enhance upward motion and induce anomalous cyclonic surface winds, increasing atmospheric instability and intensifying precipitation. This precipitation enhancement is largely confined to the Mediterranean Sea and adjacent northern land areas, particularly the Anatolian, Italian, and Balkan peninsulas. At the hemispheric scale, MedP3 produces a Northern Hemisphere warming response. The associated interhemispheric thermal contrast shifts the intertropical convergence zone slightly northward, resulting in increased precipitation in the northern tropics. Overall, our study shows that changes in MedSSTs could have climatic impacts on both regional and global scales. Significance Statement The Mediterranean Sea is important in shaping the climate of the Mediterranean region, which is recognized as a climate change hotspot with future projections indicating significant drying. This modeling study provides valuable insights into the Mediterranean Sea's influence on both regional and global climate systems. Results reveal that a warmer Mediterranean Sea enhances upward atmospheric motion over the region, disrupting both Hadley and Ferrel circulations. The enhanced atmospheric instability increases regional precipitation. A warmer Mediterranean Sea also heats the midlatitudes in the Northern Hemisphere. The greater temperature gradient between the polar regions and the northern midlatitudes strengthens the polar jet stream, which likely causes the intertropical convergence zone to shift slightly northward. These findings underscore the Mediterranean's impact on regional and global atmospheric circulation and climate dynamics. |
| Publication Title | Journal of Climate |
| Publication Date | Jun 1, 2026 |
| Publisher's Version of Record | https://doi.org/10.1175/jcli-d-25-0540.1 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d72b93mx |
| OpenSky Listing | View on OpenSky |
| CGD Affiliations | OS |