The 2025 Mediterranean marine heatwaves through sea surface temperature analogues
- 1Laboratoire des Sciences du Climat et de l'Environnement (Gif-sur-Yvette, France)
- 2London Mathematical Laboratory (London, United Kingdom)
- 3Sorbonne Université (Paris, France)
Abstract
The Mediterranean Sea experienced an exceptional marine heatwave throughout June–July 2025. Here we analyse this event using an analogue framework that differs from the common atmospheric circulation-based analogue attribution approach. Instead of identifying atmospheric circulation analogues first, we search directly for historical analogues of the observed sea surface temperature (SST) anomaly pattern of the 20 to 30 June 2025 build-up and peak phase, and then compare the associated atmospheric and air-sea surface conditions in a past (1950 to 1986) and a present (1987 to 2024) period, using ERA5 daily fields over the Mediterranean between June and September. Our results suggest that the present period exhibits higher SST anomalies than the past one, with the strongest positive differences over the western Mediterranean and the Adriatic Sea. Warmer 2 m air temperatures over surrounding land areas and higher net shortwave radiation over large parts of the basin are also observed, while sea level pressure, wind speed, latent heat flux, sensible heat flux, and longwave radiation display smaller and more spatially heterogeneous changes. Thus, the 2025 event occurred in a warmer thermodynamic background than analogous SST patterns in earlier decades. Since the analogue framework cannot fully separate externally forced trends from internal variability and it does not explicitly resolve ocean dynamical processes, these results do not constitute a complete formal attribution on their own. Nevertheless, the analogue analysis supports the interpretation that long term warming contributed substantially to the intensity of the 2025 Mediterranean marine heatwave and shows how SST analogue comparisons can complement existing attribution approaches for marine extremes. Statistical tests confirm that long-term warming trend has amplified Mediterranean SST extremes by up to 1.5°C and associated heat exchange processes, though shifts in large-scale natural climate variability may also influence these outcomes, complicating attribution. Nonetheless, the dominant contribution to the 2025 marine heatwave severity is attributable to anthropogenic forcing. This study proves the effectiveness of the analogue method for assessing extreme events, also including marine heatwaves, in a warming Mediterranean context.
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BibTeX
@article{faranda20262025,
title = {{The 2025 Mediterranean marine heatwaves through sea surface temperature analogues}},
author = {Davide Faranda and Thibault Guinaldo and Francisco Pastor and Tommaso Alberti and Samira Khodayar},
journal = {Natural Hazards and Earth System Sciences},
year = {2026},
month = oct,
doi = {10.5194/nhess-26-5407-2026},
url = {https://nhess.copernicus.org/articles/26/5407/2026/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The 2025 Mediterranean marine heatwaves through sea surface temperature analogues
AU - Davide Faranda
AU - Thibault Guinaldo
AU - Francisco Pastor
AU - Tommaso Alberti
AU - Samira Khodayar
PY - 2026
DA - 2026/10/30
JO - Natural Hazards and Earth System Sciences
DO - 10.5194/nhess-26-5407-2026
UR - https://nhess.copernicus.org/articles/26/5407/2026/
AB - The Mediterranean Sea experienced an exceptional marine heatwave throughout June–July 2025. Here we analyse this event using an analogue framework that differs from the common atmospheric circulation-based analogue attribution approach. Instead of identifying atmospheric circulation analogues first, we search directly for historical analogues of the observed sea surface temperature (SST) anomaly pattern of the 20 to 30 June 2025 build-up and peak phase, and then compare the associated atmospheric and air-sea surface conditions in a past (1950 to 1986) and a present (1987 to 2024) period, using ERA5 daily fields over the Mediterranean between June and September. Our results suggest that the present period exhibits higher SST anomalies than the past one, with the strongest positive differences over the western Mediterranean and the Adriatic Sea. Warmer 2 m air temperatures over surrounding land areas and higher net shortwave radiation over large parts of the basin are also observed, while sea level pressure, wind speed, latent heat flux, sensible heat flux, and longwave radiation display smaller and more spatially heterogeneous changes. Thus, the 2025 event occurred in a warmer thermodynamic background than analogous SST patterns in earlier decades. Since the analogue framework cannot fully separate externally forced trends from internal variability and it does not explicitly resolve ocean dynamical processes, these results do not constitute a complete formal attribution on their own. Nevertheless, the analogue analysis supports the interpretation that long term warming contributed substantially to the intensity of the 2025 Mediterranean marine heatwave and shows how SST analogue comparisons can complement existing attribution approaches for marine extremes. Statistical tests confirm that long-term warming trend has amplified Mediterranean SST extremes by up to 1.5°C and associated heat exchange processes, though shifts in large-scale natural climate variability may also influence these outcomes, complicating attribution. Nonetheless, the dominant contribution to the 2025 marine heatwave severity is attributable to anthropogenic forcing. This study proves the effectiveness of the analogue method for assessing extreme events, also including marine heatwaves, in a warming Mediterranean context.
SN - 1684-9981
SN - 1561-8633
ER -