Articles | Volume 8, issue 3
Geosci. Model Dev., 8, 603–618, 2015
Geosci. Model Dev., 8, 603–618, 2015
Development and technical paper
16 Mar 2015
Development and technical paper | 16 Mar 2015

Regional climate hindcast simulations within EURO-CORDEX: evaluation of a WRF multi-physics ensemble

E. Katragkou1, M. García-Díez2,3, R. Vautard4, S. Sobolowski5, P. Zanis1, G. Alexandri6, R. M. Cardoso7, A. Colette8, J. Fernandez3, A. Gobiet9, K. Goergen10,11,12, T. Karacostas1, S. Knist10, S. Mayer5, P. M. M. Soares7, I. Pytharoulis1, I. Tegoulias1, A. Tsikerdekis1, and D. Jacob13 E. Katragkou et al.
  • 1Department of Meteorology and Climatology, School of Geology, Aristotle University of Thessaloniki, Thessaloniki, Greece
  • 2Climate Dynamics and Impacts Unit, Institut Català de Ciències del Clima, Barcelona, Catalonia, Spain
  • 3Department of Applied Mathematics and Computer Science, Universidad de Cantabria, Santander, Spain
  • 4Laboratoire des Sciences du Climat et de l'Environment, IPSL, CEA/CNRS/UVSQ, Gif sur Yvette, France
  • 5Uni Research Climate & Bjerknes Center for Climate Research, Bergen, Norway
  • 6Laboratory of Atmospheric Physics, School of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
  • 7Instituto Dom Luiz, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal
  • 8Institut National de l' Environment industriel et des risques (INERIS), Verneuil en Halatte, France
  • 9Wegener Center for Climate and Global Change, University of Graz, Graz, Austria
  • 10Meteorological Institute, University of Bonn, Bonn, Germany
  • 11Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Jülich, Germany
  • 12Luxembourg Institute of Science and Technology – former Centre de Recherche Public – Gabriel Lippmann (CRPGL), Belvaux, Luxembourg
  • 13Climate Service Centre 2, Hamburg, Germany

Abstract. In the current work we present six hindcast WRF (Weather Research and Forecasting model) simulations for the EURO-CORDEX (European Coordinated Regional Climate Downscaling Experiment) domain with different configurations in microphysics, convection and radiation for the time period 1990–2008. All regional model simulations are forced by the ERA-Interim reanalysis and have the same spatial resolution (0.44°). These simulations are evaluated for surface temperature, precipitation, short- and longwave downward radiation at the surface and total cloud cover. The analysis of the WRF ensemble indicates systematic temperature and precipitation biases, which are linked to different physical mechanisms in the summer and winter seasons. Overestimation of total cloud cover and underestimation of downward shortwave radiation at the surface, mostly linked to the Grell–Devenyi convection and CAM (Community Atmosphere Model) radiation schemes, intensifies the negative bias in summer temperatures over northern Europe (max −2.5 °C). Conversely, a strong positive bias in downward shortwave radiation in summer over central (40–60%) and southern Europe mitigates the systematic cold bias over these regions, signifying a typical case of error compensation. Maximum winter cold biases are over northeastern Europe (−2.8 °C); this location suggests that land–atmosphere rather than cloud–radiation interactions are to blame. Precipitation is overestimated in summer by all model configurations, especially the higher quantiles which are associated with summertime deep cumulus convection. The largest precipitation biases are produced by the Kain–Fritsch convection scheme over the Mediterranean. Precipitation biases in winter are lower than those for summer in all model configurations (15–30%). The results of this study indicate the importance of evaluating not only the basic climatic parameters of interest for climate change applications (temperature and precipitation), but also other components of the energy and water cycle, in order to identify the sources of systematic biases, possible compensatory or masking mechanisms and suggest pathways for model improvement.