1. Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology MeteoSwiss WG 3: Overview status report COSMO General Meeting, 19 September 2006 Detailed status reports available on the COSMO web-site Acknowledgments: WG 3 members Marco Arpagaus

2. 2 WG3: Overview status report WP 3.1: Planetary boundary layer 3.1.1: Surface transfer scheme and turbulence scheme 3.1.1.1: Revision of the transfer scheme and the near surface diagnosis together with the completion of relevant documentation 3.1.1.2: Reorganisation of the turbulence scheme and implementation of the 3-d extension together with the completion of relevant documentation 3.1.1.3: Extensions of the SC framework 3.1.1.4 New concept for the roughness layer extension of the current turbulence scheme 3.1.1.5: Higher vertical resolution for the lowest part of the boundary layer (NN) 3.1.2: Special boundary layer matters 3.1.2.1: Urban turbulence parametrisation

3. 3 WG3: Overview status report Revision of the near surface diagnosis (Raschendorfer) Interpolation of 2m-level: Diagnosis: Too strong amplitude of diurnal cycle (T!) for grid points with large roughness length compared to SYNOP measurements Solution: Exponential canopy profiles represent the grid point mean but not the special SYNOP-station surface (lawn) Logarithmic free turbulent profile function with roughness length adopted to a typical SYNOP station Note: A similar treatment had been introduced for 10m wind some years ago.

4. 4 WG3: Overview status report Revision of the near surface diagnosis (Raschendorfer) Daily cycle of near surface temperatures for a large roughness length: actual version with exponential canopy profile test version with SYNOP-station profile

5. 5 WG3: Overview status report Single column model studies (Buzzi & Rotach)  poster Operational configuration, after 9h of simulation

6. 6 WG3: Overview status report Single column model studies (Buzzi & Rotach) too strong mixing (K H,K M ≥ 1 m 2 /s) instabilities due to thin vertical layers (mainly via circulation term) K H,K M ≥ 0.1 m 2 /s … - see poster!

7. 7 WG3: Overview status report WP 3.2: Microphysics 3.2.1: Improvement of the three-category ice scheme  poster by Thorsten Reinhardt

8. 8 WG3: Overview status report Improvement of the three-category ice scheme (Reinhardt) Conclusions: In LMK simulations of idealized strong convection simulated precipitation can be highly sensitive to the assumed graupel particle properties. This sensitivity was much weaker in simulations of real weather situations. Changing graupel properties toward those of more hail- like properties does not cure problem of underestimated convection in LMK. Therefore a change in the parameterization of the graupel category in the microphysics scheme was not introduced. The WP is completed.

9. 9 WG3: Overview status report WP 3.3: Clouds WP 3.4: Convection no regular WPs - but: Evaluation of the Kain-Fritsch /Bechtold convection scheme (Dierer & Schubiger)  poster all < 800m 800m – 1500m > 1500m black: operational; red: Kain-Fritsch/Bechtold

10. 10 WG3: Overview status report WP 3.5: Radiation 3.5.1: Cloud-radiation interaction  poster by Alessio Bozzo 3.5.2: Improve radiation treatment at small mesh-sizes

11. 11 WG3: Overview status report Cloud-radiation interaction (Bozzo) Heating rates: water clouds: ok ice clouds: ok for SW, see picture for LW Surface fluxes: water clouds: LM clouds too opaque to SW, ok for LW ice clouds: ok for SW, LW needs further inspection

12. 12 WG3: Overview status report WP 3.6: Soil processes 3.6.1: Revision of external parameters for plants 3.6.2: Implementation of lake model into the LM 3.2.3: Intercomparison of soil models in the framework of soil moisture validation  poster by Gerd Vogel no formal WP: Aspects on running the soil model for climate runs  poster by Andreas Will no formal WP: High resolution soil moisture analysis by assimilation of observations in LM-TERRA  poster by Felix Ament

13. 13 WG3: Overview status report Implementation of lake model into the LM (Mironov) Ice thickness Lake HjalmarenLake Balaton Lake surface temperature (T s = T i for frozen lakes): green - forecast with LM-FLake, black - LM SST Analysis

14. 14 WG3: Overview status report Intercomparison of soil models in the framework of soil moisture validation (Vogel et al.) 3-9 cm 9-27 cm 27-81 cm

15. 15 WG3: Overview status report WP 3.7: Sub-km version 3.7.1: High-resolution numerical modelling of deep moist convection dynamics

16. 16 WG3: Overview status report WP 3.8: Validation and related matters 3.8.1: Development of a tool for extended parameter determination (NN)

17. 17 WG3: Overview status report WP 3.9: Tackle observed model deficiencies 3.9.1: Improve diagnosis of convective and turbulent gusts 3.9.2: Investigate reason for cold/moist bias in PBL

18. 18 WG3: Overview status report Priority projects Towards Unified Turbulence-Shallow Convection Scheme (‘UTCS’; PL: Dmitrii Mironov)  talk by Matthias Raschendorfer Tackle deficiencies in precipitation forecasts (‘QPF’; PL: Marco Arpagaus)  talks by …  … Uli Damrath (task 1: find poor QPF cases)  … Axel Seifert (task 2: suggest model changes)