Preprints
https://doi.org/10.5194/wcd-2022-54
https://doi.org/10.5194/wcd-2022-54
 
17 Oct 2022
17 Oct 2022
Status: this preprint is currently under review for the journal WCD.

What distinguishes 100-year precipitation extremes over Central European river catchments from more moderate extreme events?

Florian Ruff and Stephan Pfahl Florian Ruff and Stephan Pfahl
  • Freie Universität Berlin, Institute of Meteorology, Carl-Heinrich-Becker-Weg 6-10, 12165 Berlin, Germany

Abstract. Historical extreme flooding events in Central European river catchments caused high socioeconomic impacts. Previous studies analysed single events in detail but did not focus on a robust analysis of the underlying extreme precipitation events in general as historical events are too rare for a robust assessment of their generic dynamical causes. This study tries to fill this gap by analysing a set of realistic daily 100-year large-scale precipitation events over five major European river catchments with the help of operational ensemble prediction data from the ECMWF. The dynamical conditions during such extreme events are investigated and compared to those of more moderate extreme events (20- to 50-year). 100-year precipitation events are generally associated with an upper-level cut-off low over Central Europe in combination with a surface cyclone southeast of the specific river catchment. The 24 hours before the event are decisive for the exact location of this surface cyclone, depending on the location and velocity of the upper-level low over Western Europe. The difference between 100-year and more moderate extreme events vary from catchment to catchment. Dynamical mechanisms such as an intensified upper-level cut-off low and surface cyclone are the main drivers distinguishing 100-year events in the Oder and Danube catchments, whereas thermodynamic mechanisms such as a higher moisture supply in the lower troposphere east of the specific river catchment are more relevant in the Elbe and Rhine catchments. For the Weser/Ems catchment, differences appear in both dynamical and thermodynamic mechanisms.

Florian Ruff and Stephan Pfahl

Status: open (until 09 Dec 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Florian Ruff and Stephan Pfahl

Florian Ruff and Stephan Pfahl

Viewed

Total article views: 256 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
165 89 2 256 23 3 1
  • HTML: 165
  • PDF: 89
  • XML: 2
  • Total: 256
  • Supplement: 23
  • BibTeX: 3
  • EndNote: 1
Views and downloads (calculated since 17 Oct 2022)
Cumulative views and downloads (calculated since 17 Oct 2022)

Viewed (geographical distribution)

Total article views: 253 (including HTML, PDF, and XML) Thereof 253 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 04 Dec 2022
Download
Short summary
In this study, we analyse the generic atmospheric processes of very extreme, 100-year precipitation events in large Central European river catchments and the corresponding differences to less extreme events, based on a large time series (~1200 years) of simulated but realistic daily precipitation events from the ECMWF. Depending on the catchment, either dynamical mechanisms, thermodynamic conditions or a combination of both distinguish 100-year from less extreme precipitation events.