Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology MeteoSwiss Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier COSMO-GM, Roma,

2 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Agenda Motivation Status of the ARPA-SIM collaboration Domain and orography filtering Namelist choices Some results Summary Future

3 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Motivation for COSMO-1 Operational target is for 2015 Why increase the grid resolution? - improve representation of forcing (e.g. topography, land use) - better capture non-linear interaction between different scales (e.g. convection) - improve use of observing systems in the assimilation step Focus mainly on Alpine region and Alpine specific problems

4 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Target: COSMO-1 suite in x daily COSMO hours forecasts 1 km grid size, 100 layers 1040 x 700 grid points IFS boundary conditions 10 km grid size, 140 layers 4x daily

5 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Target: COSMO-E suite in x daily COSMO-E +5 days forecasts 3 km grid size 21 members VarEPS boundary conditions 20 km 2x daily

6 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Status of the ARPA-SIM collaboration √Common domain Test if a common configuration can be used and a common evaluation of results operated Nesting strategy compare C-1 in C-7 with C-1 in C-2 Decrease damping in upper layers cf. Wolfgang Langhans 1 ) Tune the orographic filtering to the stability of the dynamics Investigate the sensitivity to the asymptotic turbulent length scale and the vertical level distribution 1 ) Convergence of numerical simulations of linear hydrostatic gravity wave, March 11, 2011

7 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier 1) eXtra filter only for masked high Steps of Orography Orography filtering (2 extremes) Rhône V. Rhine COSMO-1 COSMO-2 COSMO-7 4  x Raymond filter + XSO 1) 750m

8 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Gradient of orography a) NO filter, max.36°, mean 6° b) Std filter, max.25°, mean 4.4° c) 400m xso, max.20°, mean 4.2° d) 300m xso, max.18°, mean 3.8° Compare (CH) to: COSMO-7: max.4°, mean 1.1° ! COSMO-2: max.15°, mean 2.8° near Mt Blanc a)b) c)d)

9 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier - Gradient problem - OLD common domain

10 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Large Alpine Domain 698 x 528 gridpoints CPU of COSMO-2 * 4 300m filter: max. gr. 18° C-1 with 750m filter: 25° COSMO-2: 15°

11 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier 3“3“C-2 Orographic spectra

12 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Namelist choices Bold for C-2 operationalRED = C-1 Dynamics time step (  t=10sec, C-2=20) advection (SL, Bott2, l3dstrang, lva_impl_dyn) If possible NO horizontal diffusion divergence damping (xkd=0.1/0.05/0.01) best choice:  upper boundary condition (nrdtau=5/2) *  t: e-folding time for damping at the model top Physics turbulence (itype_turb=3)

13 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier COSMO-1 cases A. Storm Carmen 12 November 2010 with different orographic smoothing needs horizontal diffusion (1 slide) B. Convective case 29 May 2010 with/without horizontal diffusion different advection codes C. Stratus case of 27 October 2009 without horizontal diffusion (no slides)

14 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier A. Energy spectra CARMEN ( ) 24h forecast (u, v, w) from 6 to 10km height Similar results for smaller time steps with hor. dif.

15 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier B. Convective case with COSMO-1 hd_corr_u_in=0.5 NO horizontal diffusion

16 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Test with a modified advection (U. Blahak) ~ 15 m/s !  Maximum nur noch ~ 3 m/s !

17 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier B. Convective case with COSMO-1 NO horizontal diffusionUli Blahak modif. advection

18 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier B. Convective case with COSMO-1 001: Uli Blahak modif. advection 003: NO horizontal diffusion 002: with horizontal diffusion [ m 3 ]

19 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier B. Convective case with COSMO-1 NO horizontal diffusion (hd) NO hd but with UB modif. advection With horizontal diffusion Time series of Max. vertical wind Max. horizontal wind

20 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier B. Convective case 29 May h forecast (u, v, w) from 6 to 10km height

21 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Summary Choice of the orographic filtering is not too bad considering the spectral evaluation but depends on the model dynamics Stable run can produce meaningless values (horizontal wind) at some particular time Possible to run cases without horizontal diffusion The advection scheme has an impact on the results (  more tests needed!)

22 COSMO-GM, Roma / Sept / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Future Set up an assimilation cycle for COSMO-1 Regular runs from the assimilation cycle Evaluate against COSMO-2 Need more test cases and/or case studies: - Convection - Stratus - Strong precipitation - Föhn