Operational COSMO of MeteoSwiss Daniel Leuenberger and Oliver Fuhrer, MeteoSwiss COSMO User Workshop, 16.12.2010

Content Selected changes in past COSMO/INT2LM versions Current operational MeteoSwiss setup Selected changes in future COSMO/INT2LM versions

COSMO (past) 4.11 Bug fix for Tiedtke convection scheme combined with Runge-Kutta dynamics Option for generalized Asselin Filter (after Williams 2009) Theta advection with limiter (option for preventing runaway cold pools in steep valleys) Option for selecting the lower boundary condition for vertical wind speed (influences pressure bias) Option for reference atmosphere with constant Brunt-Vaisala-frequency (idealized runs only) Introduction of additional external parameter fields for => surface emissivity (in the radiation) => aerosol distributions (in the radiation) 4.12 Computation of vorticity and potential vorticity Horizontal diffusion freely adjustable inside domain and in boundary zone

Current operational setup New IFS LBC with 0.125deg (16km) mesh size New diagnostic field: Height of PBL Horizontal diffusion of wind inside domain (COSMO-7 only) Bug fix of Tiedtke scheme for RK (influences precipitation) Use semi-implicit turbulent mixing of TKE Positive definite humidity advection using Bott scheme and full Strang splitting Namelist switches available under COSMO http://www.cosmo-model.org/content/tasks/operational/nmlDoc/cosmoDefault.htm INT2LM http://www.cosmo-model.org/content/tasks/operational/nmlDoc/int2lmDefault.htm

COSMO (future, up to 4.16) Bugfixes for the interpolation from ECMWF driving data Dynamics: (by Michael Baldauf) => The logical switch lva_impl_dyn, to choose an implicit vertical advection in the RK-scheme, has been replaced by a string: y_vert_adv_dyn Several options can be chosen now: 'impl2': 2nd order implicit (as was lva_impl_dyn=.TRUE.) 'expl': explicit (as was lva_impl_dyn=.FALSE.) 'impl3': 3rd order implicit (new) Microphysics: (by Axel Seifert) In hydci_pp (itype_gscp=3) the density correction of the terminal fall velocity of raindrops and snowflakes is now taken into account. Multilayer snow model (under testing)

INT2LM (future, up to 1.14) Implementation of reading data with grib_api Enabled reproducibility when interpolating from a regular coarse grid domain to the COSMO-Model: Problem: The computation of surface values for isolated points (lakes in the land; islands in the oceans) was looking for the next grid point with the same land-sea-mask. Depending on the domain decomposition, this could lead to different points. Bugfix in src_grids for the computation of interpolation weights The computations of the interpolation weights has been corrected. In some cases, when input grid point and COSMO grid point are identical, it could happen that unrealistic high interpolation weights had been computed. Now it is ensured that these weights are between 0 and 1. Adaptations for NetCDF I/O of 3D field HORIZON The NetCDF I/O has been adapted to deal with the three-dimensional external parameter HORIZON, necessary for the topographical corrections (by Anne Roches, CH)

Further remarks All code versions available in C2SM SVN repository Official versions https://cosmo.cscs.ch/cosmo/trunk_tags/cosmo_c2sm Operational versions https://cosmo.cscs.ch/cosmo/trunk_tags/cosmo_opr