In September 2023, Cyclone Daniel formed in the Mediterranean, severely affecting Greece and Libya, and becoming the deadliest storm in Mediterranean history. The Mediterranean’s unusually high sea surface temperatures (SST) likely contributed to the cyclone’s intensity and extreme rainfall. Greece saw over 700 mm of rain in 18 h, while Libya experienced daily records exceeding 400 mm, leading to catastrophic infrastructure failures. Our hypothesis is that high SSTs provided additional energy and moisture fueling Daniel’s intensification. Using the Weather Research and Forecasting model, we conducted numerical experiments to quantify the role of high SSTs during the event. Comparing actual conditions with a counterfactual scenario, we found that the long-term global warming signal in SSTs significantly increased the storm’s intensity and precipitation. This study underscores the need to understand rising SSTs contribution to predicting and mitigate future tropical-like cyclones as global temperatures increase.

2023 年 9 月，气旋“丹尼尔”在地中海形成，严重影响了希腊和利比亚，成为地中海历史上最致命的风暴。地中海异常高的海面温度 （SST） 可能是导致气旋强度和极端降雨的原因。希腊在 18 小时内降雨量超过 700 毫米，而利比亚的日降雨量超过 400 毫米，导致灾难性的基础设施故障。我们的假设是，高 SST 提供了额外的能量和水分，推动了丹尼尔的增强。使用天气研究和预报模型，我们进行了数值实验，以量化高 SST 在事件期间的作用。将实际情况与反事实情景进行比较，我们发现 SST 中的长期全球变暖信号显着增加了风暴的强度和降水。这项研究强调了了解随着全球气温升高，不断上升的 SST 对预测和减轻未来类似热带气旋的贡献的必要性。