Large‐eddy simulations over Germany using ICON: a comprehensive evaluation

Large-eddy simulations (LES) with the new ICOsahedral Non-hydrostatic atmosphere model (ICON) covering Germany are evaluated for four days in spring 2013 using observational data from various sources. Reference simulations with the established Consortium for Small-scale Modelling (COSMO) numerical weather prediction model and further standard LES codes are performed and used as a reference. This comprehensive evaluation approach covers multiple parameters and scales, focusing on boundary-layer variables, clouds and precipitation. The evaluation points to the need to work on parametrizations influencing the surface energy balance, and possibly on ice cloud microphysics. The central purpose for the development and application of ICON in the LES configuration is the use of simulation results to improve the understanding of moist processes, as well as their parametrization in climate models. The evaluation thus aims at building confidence in the model's ability to simulate small- to mesoscale variability in turbulence, clouds and precipitation. The results are encouraging: the high-resolution model matches the observed variability much better at small- to mesoscales than the coarser resolved reference model. In its highest grid resolution, the simulated turbulence profiles are realistic and column water vapour matches the observed temporal variability at short time-scales. Despite being somewhat too large and too frequent, small cumulus clouds are well represented in comparison with satellite data, as is the shape of the cloud size spectrum. Variability of cloud water matches the satellite observations much better in ICON than in the reference model. In this sense, it is concluded that the model is fit for the purpose of using its output for parametrization development, despite the potential to improve further some important aspects of processes that are also parametrized in the high-resolution model.

Hartwig Deneke | Volker Wulfmeyer | Günther Zängl | Norbert Kalthoff | Clemens Simmer | Hans-Christian Hege | Kathrin Wapler | Susanne Crewell | Andreas Behrendt | Johannes Quaas | Moritz Hanke | L. Scheck | Holger Baars | Silke Trömel | Emiliano Orlandi | Felix Ament | Bernhard Mayer | Niklas Röber | Axel Seifert | Alexander Kuhn | Corinna Hoose | Fabian Senf | Christopher Moseley | Daniel Klocke | Bjorn Stevens | Matthias Brueck | A. Dipankar | Ulrich Blahak | Michael Weniger | Petra Friederichs | Patric Seifert | Andreas Macke | Stefan Kneifel | Sandra Steinke | Xinxin Xie | Akio Hansen | Rieke Heinze | Cintia Carbajal Henken | Catrin I. Meyer | Panos Adamidis | Florian Pantillon | Bernhard Pospichal | Raquel Evaristo | Paolo Di Girolamo | Sebastian Bley | Peter Knippertz | Jürgen Fischer | B. Stevens | H. Hege | B. Mayer | U. Blahak | P. Friederichs | P. Seifert | S. Kneifel | D. Klocke | H. Deneke | P. Di Girolamo | C. Simmer | F. Ament | S. Crewell | Akio Hansen | M. Brueck | G. Zängl | H. Baars | S. Bley | J. Fischer | P. Knippertz | A. Macke | C. Moseley | C. Hoose | J. Quaas | A. Seifert | C. Meyer | A. Dipankar | V. Wulfmeyer | N. Kalthoff | F. Pantillon | K. Wapler | O. Sourdeval | Rieke Heinze | C. C. Henken | N. Röber | L. Scheck | F. Senf | R. Neggers | A. Kuhn | B. Pospichal | A. Behrendt | T. Jahns | S. Trömel | C. Barthlott | M. Weniger | S. Steinke | Christopher Frank | Shravan Kumar Muppa | Vera Maurer | Odran Sourdeval | Christian Barthlott | E. Orlandi | S. Brdar | Christopher Frank | Xinxin Xie | Raquel Evaristo | Slavko Brdar | Tobias Göcke | Ksenia Gorges | L. B. Hande | Thomas Jahns | Thriza van Laar | Roeland A. J. Neggers | Pavan Kumar Siligam | Dan Zhang | V. Maurer | S. K. Muppa | M. Hanke | P. Adamidis | Dan Zhang | L. Hande | Ksenia Gorges | P. K. Siligam | Tobias Göcke | Thriza van Laar | Slavko Brdar

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