1. COSMO model activities in the atmospheric dynamics group at ETH Heini Wernli Claudia Frick Stephan Pfahl Andreas Winschall Astrid Kerkweg Maxi Böttcher Matthias Zimmer Gregor Gläser Christiane Hofmann

2. What for do we use the COSMO model? Studies on the dynamics of weather systems Studies on the atmospheric water cycle Studies on atmospheric chemistry and transport

3. How do we use the COSMO model? Studies on the dynamics of weather systems high-resolution model simulations sensitivity experiments (on/off of physical processes) test / improvement of physical parameterizations Studies on the atmospheric water cycle COSMOtag: implementation of water tagging COSMOiso: implementation of stable water isotopes Studies on atmospheric chemistry and transport development of ECHAM5-COSMO-MESSy (comprehensive, online-coupled global-regional chemistry model system)

4. EUMETSAT: RGB-composite Saharan dust storm March 2004 0°E airborne dust clouds 40°N 20°N Sahara Desert 1000 km Gläser & Knippertz

5. NS Z Y coldpool ρ c > ρ s ρsρs  threshold for |v 10m | ≈ 10-12 m/s  how to exceed the threshold ?? Concept of the dust mobilisation resulting flow v res = v b + |v c |v res = v b - |v c | vbvb vcvc vcvc vbvb vbvb v b : background flow v c : outflow out of the coldpool Gläser & Knippertz

6. coldpool heating due to condensation, freezing, resublimation cooling due to evaporation, melting, sublimation Dipole of latent heating/cooling N-S-cross-section at 4°ECOSMO 2.8 km northern latitude, deg pressure, hPa K/h Gläser & Knippertz

7. Gust front moving into the Sahara longitude, deg latitude, deg max:> 14 m/s min:< 2 m/s "undisturbed" flow: Ø 8-10 m/s → Δ = ± 6-8 m/s ! COSMO 2.8 km 10m wind field (m/s) Gläser & Knippertz

8. 19-21 December 2005 low-level PV and SLP from ECMWF analyses Pressure deepening of 34hPa/24h ! Rapid North Atlantic cyclogenesis Maxi Böttcher

9. Rapid North Atlantic cyclogenesis COSMO model hindcast simulations Horizontal resolution of 14km, 40 vertical layers Initial and boundary data (every 6h) from ECMWF analyses 4 model simulations for early phase of development: - control - dry run - no LHR in box - SST-3K in box ECMWF analysis Maxi Böttcher

10. controldry no LHR in box Rapid North Atlantic cyclogenesis COSMO model sensitivity experiments (+42h) SST-3K in box Maxi Böttcher

11. Parameterization of snow melting Intense snow storms occur during situation with T s ≈ 0°C, typically with presence of melting layer above the surface current melting scheme: if T > 0°C then snow rain Claudia Frick

12. Parameterization of snow melting Intense snow storms occur during situation with Ts ≈ 0°C, typically with presence of melting layer above the surface current melting scheme: if T > 0°C then snow rain Now with 1D-COSMO in cooperation with Axel Seifert: development of new scheme with liquid water fraction T(z,t) from radiosonde snow mixing ratio(z,t) snowmelt mix. ratio(z,t) Claudia Frick

13. + 00-UTC runs o 09-UTC runs Verification of COSMO model QPFs with SAL Summer 2007, German part of COPS region Forced frontal convectionHigh-pressure convection COSMO-EU COSMO-DE Matthias Zimmer

14. 18 R 0 18 R 1 < 18 R 0 18 R 2 < 18 R 1 In principle, stable isotopes allow to reconstruct water transport paths and atmospheric conditions during phase transitions (e.g. temperature) simultaneously. Stable water isotopes in the COSMO model Stephan Pfahl

15. Water transport and phase transitions in the model Inclusion of parallel water cycle in the model affects: advection (Bott scheme) turbulent transport implicit numerical scheme (not positive def.) influence of subgrid scale clouds (?) convection parameterization cloud microphysics, saturation adjustment still missing: land surface scheme Output: δ 18 O vap (x,t), δ 18 O prec (x,t), δ 2 H vap (x,t), δ 2 H prec (x,t) Stephan Pfahl

16. deuterium excess in near-surface water vapour left: COSMO simulation; right: alternative Lagrangian diagnostic First application of COSMOiso (18 Nov 2001) Stephan Pfahl

17. MACCHIATO Modeling AtmosperiC CHemIstry And Transport fom the global tO the local scales Modeling of atmospheric chemistry on all scales  consistent treatment of chemistry on all scales  use ECHAM5/MESSy (boundary data)  develop COSMO/MESSy MESSy: Modular Earth Submodel System contains submodels for chemistry calculation and diagnostic; each process (chemistry, deposition, sedimentation etc.) is a seperate (switchable) submodel Aims: zooming option for e.g., campaign modelling, down- scaling of climate projections, chemical weather forecasts etc. Astrid Kerkweg & Patrick Jöckel (DLR)

18. An arbitrary number of COSMO models run in parallel in the same MPI environment and provide the required boundary data via MPI exchange on-line. => avoid dumping, storage and input of huge data amounts (e.g., some 100 chemical species) COSMO 1 COSMO 2 COSMO 3 COSMO X... COSMO 31 COSMO 32 COSMO 321 ECHAM5 COSMO 12 The vision of “ONLINE-COUPLING”

19. Summary COSMO is the meteorological model in our group Strong interest in exchange & cooperation with MeteoSwiss and C2SM Model applications - detailed analysis of real case study (sensitivity) experiments for various weather events - idealized channel-model baroclinic wave experiments Model development - new melting scheme with liquid water fraction - implementation of tagging and stable water isotope physics - coupling with ECHAM5-MESSy for high-resolution chemistry simulations with consistent boundary conditions