EGU2020-10506
https://doi.org/10.5194/egusphere-egu2020-10506
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evaluation of extreme precipitation over the Nordic region using a convection-permitting regional climate model

Erika Toivonen1, Danijel Belušić2, Emma Dybro Thomassen3,4, Peter Berg2, Ole Bøssing Christensen3, Andreas Dobler5, Anita Verpe Dyrrdal5, Jan Erik Haugen5, Kirsti Jylhä1, Erik Kjellström2, Oskar Landgren5, Petter Lind2, David Lindstedt2, Dominic Matte6, Antti Mäkelä1, Jonas Olsson2, Rasmus Anker Pedersen3, Fuxing Wang2, and Wei Yang2
Erika Toivonen et al.
  • 1Finnish Meteorological Institute, Helsinki, Finland (erika.toivonen@fmi.fi)
  • 2Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
  • 3Danish Meteorological Institute, Copenhagen, Denmark
  • 4Technical University of Denmark, Kgs. Lyngby, Denmark
  • 5Norwegian Meteorological Institute, Oslo, Norway
  • 6University of Copenhagen, Niels Bohr Institute, Copenhagen, Denmark

Extreme precipitation events have a major impact upon our society. Although many studies have indicated that it is likely that the frequency of such events will increase in a warmer climate, little has been done to assess changes in extreme precipitation at a sub-daily scale. Recently, there is more and more evidence that high-resolution convection-permitting models (CPMs) (grid-mesh typically < 4 km) can represent especially short-duration precipitation extremes more accurately when compared with coarser-resolution regional climate models (RCMs).

This study investigates sub-daily and daily precipitation characteristics based on hourly output data from the HARMONIE-Climate model at 3-km and 12-km grid-mesh resolution over the Nordic region between 1998 and 2018. The RCM modelling chain uses the ERA-Interim reanalysis to drive a 12-km grid-mesh simulation which is further downscaled to 3-km grid-mesh resolution using a non-hydrostatic model set-up.

The statistical properties of the modeled extreme precipitation are compared to several sub-daily and daily observational products, including gridded and in-situ gauge data, from April to September. We investigate the skill of the model to represent different aspects of the frequency and intensity of extreme precipitation as well as intensity–duration–frequency (IDF) curves that are commonly used to investigate short duration extremes from an urban planning perspective. The high grid resolution combined with the 20-year-long simulation period allows for a robust assessment at a climatological time scale and enables us to examine the added value of high-resolution CPM in reproducing precipitation extremes over the Nordic region. Based on the tentative results, the high-resolution CPM can realistically capture the characteristics of precipitation extremes, for instance, in terms of improved diurnal cycle and maximum intensities of sub-daily precipitation.

How to cite: Toivonen, E., Belušić, D., Thomassen, E. D., Berg, P., Christensen, O. B., Dobler, A., Dyrrdal, A. V., Haugen, J. E., Jylhä, K., Kjellström, E., Landgren, O., Lind, P., Lindstedt, D., Matte, D., Mäkelä, A., Olsson, J., Pedersen, R. A., Wang, F., and Yang, W.: Evaluation of extreme precipitation over the Nordic region using a convection-permitting regional climate model, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10506, https://doi.org/10.5194/egusphere-egu2020-10506, 2020

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