1,2,3,1- 1Agriculture research organisation, Volcani Institute, Soil, Water and Environmental Sciences, Rishon LeZion, Israel (bj11@iitbbs.ac.in)
- 2Department of Physical, Chemical and Natural Systems, Pablo de Olavide University, Spain
- 3Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
Extreme stratospheric polar vortex events, including sudden stratospheric warmings (SSWs) and episodes of strong polar vortex, are known to influence wintertime surface weather by modulating large-scale circulation patterns. While previous studies have primarily focused on their impacts over the North Atlantic and northern Europe, the effects on Mediterranean storm activity remain less well quantified. In this study, we examine the tropospheric response to SSW events from 1979 to 2020, with a particular focus on the associated changes in cyclone activity over the Mediterranean region.
Using a composite analysis of 28 SSW events within the study period, we examine the temporal and spatial evolution of cyclone frequency, genesis density, and associated dynamical fields before and after SSW onset. Seasonal and daily climatological signals are removed to isolate anomalies directly linked to stratosphere-troposphere coupling. Our results show a clear increase in cyclone activity over North Africa and the Atlantic coast of the Iberian Peninsula, associated with increased precipitation over western and southern Europe following SSW events. This is consistent with a southward displacement of the midlatitude jet and storm track. This shift is supported by enhanced upper-level wind speeds, divergence, and potential vorticity anomalies over the region during the post-SSW 2-month period. Despite the robust composited signal, substantial inter-event variability is observed, indicating that not all SSWs lead to an identical response. These findings highlight the importance of event-to-event differences in determining regional storm impacts.
Overall, this study demonstrates that stratospheric polar vortex disruptions can significantly modulate Mediterranean storms on subseasonal timescales, highlighting the potential value of stratospheric information for enhancing the predictability of wintertime extreme weather over southern Europe and the Mediterranean Basin.
Keywords: Sudden stratospheric warming; polar vortex; Mediterranean cyclones; jet stream; stratosphere–troposphere coupling; subseasonal variability
How to cite: Jangir, B., Álvarez-Castro, C., Peña Ortiz, C., Gallego Puyol, D., Raveh-Rubin, S., and Strobach, E.: Impact of Sudden Stratospheric Warming on the Genesis of Mediterranean Cyclones and Associated Precipitation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13596, https://doi.org/10.5194/egusphere-egu26-13596, 2026.
