ESDD

Earth System Dynamics Discussions

ESDD

Earth Syst. Dynam. Discuss.

2190-4995

Göttingen, Germany

10.5194/esd-2022-24

Vb-cyclones and associated North-Western Mediterranean Sea state in regional coupled climate simulations: evaluation and projection

Pothapakula

Praveen Kumar

https://orcid.org/0000-0002-5654-7975

¹ ² Hoff

Amelie

https://orcid.org/0000-0001-8546-4100

¹ ³ Obermann-Hellhund

Anika

¹ Keber

Timo

¹ Ahrens

Bodo

https://orcid.org/0000-0002-6452-3180

Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt am Main, Altenhöferallee 1, 60438 Frankfurt am Main, Germany

now at: Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, 76344, Baden-Württemberg, Germany

now at: Deutscher Wetterdienst, Offenbach, Germany

Deutsche Forschungsgemeinschaft

FOR 2416

17 08 2022

2022 1 29

2022

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://esd.copernicus.org/preprints/esd-2022-24/

The full text article is available as a PDF file from https://esd.copernicus.org/preprints/esd-2022-24/esd-2022-24.pdf

Vb-cyclones propagating from the North-Western Mediterranean Sea (NWMS) into central Europe are often associated with extreme precipitation. This study explores the state and process chain linking the NWMS state and the Vb-cyclone precipitation in the Danube, Elbe, and Odra catchments in regional coupled atmosphere-ocean climate simulations with COSMO-CLM+NEMO. Two high-resolution simulations, an evaluation simulation (1951–2005) downscaling the centennial ERA-20C reanalysis and a continuous simulation (historical 1951–2005 + RCP8.5 future scenario 2006–2099) downscaling the EC-EARTH global climate data set are used for this purpose. The results show a good agreement in mean annual Vb-cyclone frequency between the evaluation (9.7 events/year) and the historical (10.1 events/year) simulations. But, there are significant discrepancies in the seasonal cycle. The mean cyclone intensity measured with minimum central pressure, track density, and precipitation rankings in the three catchments also show good agreement. The simulations for the future period show a basin-average SST warming of ≈ 2.5–3 K by the end of 21st century, but insignificant changes in Vb-cyclone frequency, mean intensity, and precipitation in the selected catchments. The NWMS sea surface temperature, evaporation, and wind speed anomalies corresponding to the Vb-cyclone precipitation rankings differ between the evaluation and historical simulations. In the evaluation simulation, Vb-cyclone precipitation rankings correspond with sea surface temperature, evaporation, and wind speed anomalies, while in the historical and the future simulation no such correspondence is seen. Especially the Adriatic and Ionian basins in the simulation driven by EC-EARTH show no sensitivity to the Vb-cyclone precipitation over the catchments. The change in the processes between evaluation and historical simulations might be due to the emergence of biases inherited from the driving EC-EARTH global simulation. The future simulation shows no significant process changes compared to the historical simulation.