On the Air Sea interaction and Future Climate Sensitivity of a Winter Tropical-Like Cyclone Jolina

This study investigates Storm Samuel (Medicane JOLINA), a cyclone that developed over the central Mediterranean during March 2026 and subsequently affected North Africa and Libya. The system originated as a baroclinic cyclone in the lee of Tunisia, evolving through a warm-seclusion phase before acquiring tropical-like characteristics during the final stages of its life cycle. The event therefore provides an ideal framework for exploring the mechanisms governing the transition between extratropical and tropical-like structures in the Mediterranean environment. A hierarchy of numerical experiments is performed using the Weather Research and Forecasting (WRF) model at convection-permitting resolution. Simulations include configurations with and without spectral nudging, experiments using observed high-resolution SST fields and SST fields from which mesoscale anomalies have been removed, a suite of uniform SST perturbation experiments, and a pseudo-global-warming (PGW) simulation based on the ensemble-mean climate change signal derived from multiple future projections. An ocean mixed-layer parameterization is employed to account for air–sea coupling processes. The results indicate that cyclone genesis and propagation are primarily controlled by large-scale atmospheric forcing and regional orographic effects, while air–sea interactions exert a secondary influence on the storm trajectory. In contrast, SST structure plays a substantially larger role in modulating cyclone morphology, convective organisation and precipitation. Mesoscale SST anomalies favour enhanced diabatic activity and more organised convection, whereas their removal leads to a weaker and less coherent precipitation response. Sensitivity experiments further highlight a systematic thermodynamic response to SST changes, while the PGW simulation suggests an amplification of precipitation-producing processes under future climate conditions. Overall, the study highlights the hybrid nature of the event and emphasises how large-scale dynamics govern cyclone evolution, while mesoscale air–sea interactions critically modulate the intensity and hydrological impacts of Mediterranean tropical-like cyclones.