Extreme Sub‐Hourly Precipitation Intensities Scale Close to the Clausius‐Clapeyron Rate Over Europe

• Published in: Geophysical research letters 2021-02, Vol.48 (3), p.n/a
• Main Authors: Vergara‐Temprado, Jesús, Ban, Nikolina, Schär, Christoph
• Format: Article
• Language: English
• Subjects: climate; extreme precipitation; modeling; projection
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2020GL089506

Over subhourly time scales, extreme precipitation events play a critical role for many sectors impacted by climate change; however, it is unclear how these events will evolve in a warmer climate. Here, we perform climate simulations using a regional climate model over the greater Alpine region at kilometer‐scale resolution. By analyzing precipitation intensities with short accumulation times, we show that the model can capture the observed percentiles of extreme subhourly precipitation measured at surface rain‐gauge stations. Then, by simulating the future climate, we show that the associated increases in intensity of subhourly extreme precipitation events grow with the intensity of the events but tends asymptotically toward 6.5% per degree warming. This suggests that the most extreme intensities scale with the Clausius‐Clapeyron scaling rate that represents the ability of a warmer atmosphere to hold more water vapor. It should be expected that these changes will lead to increased risks of flash flooding, land‐slides, and erosion over Europe in a warmer climate. Plain Language Summary The evolution of very short rain events in a warmer climate over a large part of Europe is addressed by using a regional climate model at very high resolution. We show that these events will intensify in a warmer climate and become about 6.5% more intense per degree of warming. Key Points Our kilometer‐scale simulations are effectively able to capture the percentiles of extreme precipitation over sub‐hourly time scales For the computational domain considered, the scaling of subhourly extreme precipitation events is limited by the Clausius‐Clapeyron rate, similar as for hourly events Short time‐scale dynamical amplifications might not play a significant role for the scaling of extreme precipitation in the future climate