1. 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-CORSO, Roma, 6.9.2011

2. 2 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Agenda Motivation Status of the ARPA-SIM collaboration Domain Outlook

3. 3 COSMO-GM-CORSO, Roma, Sept. 2011 / 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. 4 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Target: COSMO-1 suite in 2015 8x daily COSMO-1 + 24 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. 5 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Target: COSMO-E suite in 2015 2x daily COSMO-E +5 days forecasts 3 km grid size 21 members VarEPS boundary conditions 20 km 2x daily

6. 6 COSMO-GM-CORSO, Roma, Sept. 2011 / 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. 7 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Orography filtering (2 extremes) Rhône V. Rhine COSMO-1 COSMO-2 COSMO-7 (1 xso 750m)

8. 8 COSMO-GM-CORSO, Roma, Sept. 2011 / 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. 9 COSMO-GM-CORSO, Roma, Sept. 2011 / 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°

10. 10 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier COSMO-1 cases Storm Carmen 12 November 2010 with different orographic smoothing needs horizontal diffusion Convective case 29 May 2010 with/without horizontal diffusion different advection codes Stratus case of 27 October 2009 without horizontal diffusion

11. 11 COSMO-GM-CORSO, Roma, Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwissGuy de Morsier Outlook Choice of the orographic filtering should be adapted to the model dynamics! Try to run unstable cases without horizontal diffusion Set up an assimilation cycle for COSMO-1 Regular runs from the assimilation cycle Evaluate against COSMO-2