A Climate Change Study of Heavy Precipitation Events in the Mediterranean and Alps
- 1The Abdus Salam International Centre for Theoretical Physics - Earth System Physics Section (ICTP-ESP), Trieste, Italy, (smueller@ictp.it)
- 2Met Office Hadley Centre (MOHC), Exeter, United-Kingdom
- 3Deutscher Wetterdienst (DWD), Offenbach, Germany
- 4Université de Toulouse (CNRM), Météo-France (CNRS), Toulouse, France
- 5Eidgenössische Technische Hochschule (ETHZ), Zürich, Switzerland
- 6Norwegian Meteorological Institute, Oslo, Norway
- 7Karlsruhe Institute of Technology (KIT), Karlruhe, Germany
- 8Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici, Regional Model and Geo-Hydrological Impacts (REMHI) Division, Caserta, Italy
- 9Uni Kassel, Kassel, Germany
- 10Koninklijk Nederlands Meteorologisch Instituut (KNMI), De Bilt, Netherlands
Flash floods rank among the most dangerous and costliest hazards of the alpine and mediterranean region. The severe convective storms causing them are influenced by both, the presence of a large body of sea water and a complex orography. These storms are the main subject of the present study and in the following referred to as heavy precipitation events (HPEs).
We here study heavy precipitation events by using an ensemble of convection permitting regional climate models and applying a tracking algorithm, and focus on their charateristic properties. The domain covers the Alps and the central part of the Mediterranean, and we investigate and compare three 10-year periods under the rcp85 forcing scenario: historical [2000-2009], near-future [2040-2049] and far-future [2090-2099].
Our analysis reproduces a most important message: even though in the future the mediterranean climate is drying, precipitation associated with heavy precipitation events is increasing. Further, HPEs will be more frequent in the future. In particular, their occurrence frequency will increases in wintertime, whereas it will decrease in summertime.
We investigate the climate change signal of characteristic properties describing the propagation, the spatial and temporal scales and the intensity of HPEs: on average HPEs travel by 10% farther [8km], they last longer by 5% [20 min], their area increases by 16% and their total rain volume by 34%. Regarding metrics of intensity the changes of the highest percentiles are greatest: the 90th percentiles of a HPE's precipitation field increases by 5.6%, the 99th percentile by 9.4% and the maximum increases by 12.7%.
Eventually we unravel the characterics for specific regions and seasons: changes are more dramatical for HPEs that cross the coastline and in wintertime.
In summary, this study confirms important messages of climate research in an ensemble of state-of-the-art regional climate models, demonstrates the capabilities of convection-permitting spatial resolution and explores the possibilities that come with applying a tracking algorithm and by looking into precipitation extremes in the Lagrangion framework of reference.
How to cite: Müller, S. K., Pichelli, E., Coppola, E., Berthou, S., Brienen, S., Caillaud, C., Demory, M.-E., Dobler, A., Feldmann, H., Mercogliano, P., Tölle, M., and de Vries, H.: A Climate Change Study of Heavy Precipitation Events in the Mediterranean and Alps, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5481, https://doi.org/10.5194/egusphere-egu22-5481, 2022.
