ANNUAL REPORT 2013 OF THE
CONVECTION RESOLVING CLIMATE
SIMULATIONS WORKING GROUP OF THE
CLM-COMMUNITY (CLM_CRCS)
Coordinators: Heimo Truhetz and Andreas Prein
With contributions from:
Nikolina Ban (ETHZ)
1 Activities in the Last Year
David Leutwyler worked on the COSMO GPU-portotype that is being developed within the POMPA
priority project. He ported the shallow convection, near surface diagnostics, lbdclim and part of the
output diagnostics to the GPU architecture using OpenAcc compiler directives. Furthermore he worked
on validation&testing of the prototype in a cloud-resolving climate setup covering Europe and running
on 144 CPU/GPU nodes.
Hanieh Hassanzadeh investigates the influence of topography on the diurnal cycle of summertime
moist convection and precipitation amount, location and timing. The idealized test-cases also help to
study the sensitivity of the diurnal cycle to the mountain size, wind profile and soil moisture.
Michael Keller investigates the diurnal cycle of summertime convection over the Alps and adjacent
areas and compares it to satellite data. Sensitivities of the diurnal cycle to ice sedimentation in the twomoment microphysics scheme are tested.
Nikolina Ban worked on projections of the future climate using cloud-resolving simulations. The
control and scenario simulations are driven by lateral boundary conditions from the Earth-System
Model of the Max-Planck-Institute (MPI-ESM-LR). The analysis of the simulations focuses on the
projections of extreme precipitation events using generalized extreme value analysis.
Andreas Prein worked on the detection of potential added value in convection permitting seasonal
simulations compared to coarser resolved simulations. Therefore a small non-hydrostatic model
ensemble was used which included CCLM, WRF, and MM5. All high resolution models were able to
improve the diurnal cycle, intensities, and spatial patterns of precipitation during summer 2007.
Additionally 2 meter temperature was improved and global radiation was increasing in all convection
permitting simulations.
2 Plans for the Next Year
WEGC has conduct ERA-Interim driven long-term (1989 to 2010) reference hindcasts with CCLM and
WRF covering the entire Alpine region on convection-permitting scales (0.0275° grid spacing) within
the framework of the project “Non-Hydrostatic Climate Modelling, Part II (NHCM-2;
http://www.nhcm-2.eu/). The ability of the models’ to capture important climate processes strongly
connected to the Alp’s massif, i.e. shielding effect and orographic precipitation, and their dependency
from turbulence parameterizations will be investigated. This will also support CCLM model
development with respect to long-term behavior of latest turbulence parameterization schemes.
WEGC’s will perform sensitivity studies (e.g., application of new fast wave solver, importance of
vertical resolution, diffusion, and 3D turbulence).
In the framework of the HighEnd:Extreme project which is funded by the Austrian Science Fund
(FWF) Wegener Center will downscale a CMIP5 GCM rcp8.5 scenario run to the convectionpermitting scales (0.0275° grid spacing) with CCLM, WRF, and REMO. Two time slices (1971 to 2000
and 2071 to 2100) will be downscaled to investigate changes in processes such as deep convection in
high end climate scenarios in the European Alpine region.
3 Relevant Publications in the Last Year
Papers:
Ban, N., J. Schmidli and C. Schär (2014): Evaluation of the cloud-resolving regional climate modelling
approach in decade-long simulations. Submitted to JGR
Prein, A. F., A. Gobiet,, M. Suklitsch, H. Truhetz, N. K. Awan, K. Keuler, and G. Georgievski (2013):
Added value of convection permitting seasonal simulations. Climate Dynamics, 41(9-10), 2655-2677.
Prein, A. F., G. J. Holland, R. M. Rasmussen, J. Done, K. Ikeda, M. P. Clark, and C. H. Liu. (2013):
Importance of Regional Climate Model Grid Spacing for the Simulation of Heavy Precipitation in the
Colorado Headwaters. Journal of Climate, 26(13).
Oral presentation:
Ban, N., J. Schmidli and C. Schär (2013): Precipitation statistics in a 10-year cloud-resolving climate
simulation. CLM Assembly, Zürich, August 27-30
Ban, N., J. Schmidli and C. Schär (2013): Evaluation of the cloud-resolving climate model approach.
Symposium The Water Cycle in a Changing Climate, ETH Zürich, July 1-2, 2013
Ban, N., J. Schmidli and C. Schär (2013): Evaluation of a 10-year Cloud-resolving climate simulation
for the greater Alpine region, ICAM, June 3 - 7, Kranjska Gora, Slovenia.
Hassanzadeh, H. (2013): Diurnal cycle of the precipitation and moist convection over topography,
October 13-18, Urban physics Autumn school, Halkidiki, Greece.
Hassanzadeh, H., J. Schmidli, W. Langhans and C. Schär (2013): Influence of topography on the
diurnal cycle of summertime moist convection over its near-and far-field regions, ICAM, 3 - 7 June,
Kranjska Gora, Slovenia.
Hassanzadeh, H. (2013): Idealized studies of summertime moist convection over topography, RCM
workshop, 4-6 February, ETH Zurich, Switzerland.
Keller, M., O. Fuhrer, J. Schmidli, R. Stöckli, M. Stengel and C. Schär (2013): Evaluation of cloudresolving simulations of summer convection with satellite data (oral), CLM-Community Assembly
2013, Aug 27 – Aug 30, 2013, Zürich, Switzerland.
Truhetz, H., A. Csáki, G. Heinrich, M. Jury, T. Mendlik, A. Prein, R. Ritter, S. Tani, R. A. I. Wilcke, A.
Gobiet (2013): Klimamodellierung im Alpenraum – neueste Entwicklungen am Wegener Center (oral),
5. Österreichischer MeteorologInnentag, Nov 6 – 7 2013, Feldkirch, Austria
Truhetz, H., A. Prein, C. Reszler (2014): Regional climate models – current status and future
applications at the Wegener Center (oral), 3rd Vienna Scientific Cluster User Workshop, Feb 24 – 25,
Neusiedl am See, Austria
Prein, A. F. (2013): Added Value of Convection Permitting Climate Simulations (CRCSs) (oral),
Invited talk at the Institut f. Atmosphäre und Klima, Zürich, Switzerland
Posters:
Leutwyler, D., D. Lüuthi, X. Lapillonne, O. Fuhrer and C. Schär (2013): Towards European-Scale
Cloud-Resolving Climate Simulations. CLM Assembly, Zürich, August 27-30
Truhetz, H. and A. Prein (2014): Towards convection permitting regional climate simulations in the
Alpine region: experiences from the Wegener Center, NIC-Symposium 2014, Feb 11 – 12, Jülich,
Germany