Matthias Raschendorfer

1. COSMO-SCM: • The SC-framework has been upgraded to COSMO_5.0 (during the visit of Ines Cerenzia) : • Various adaptions to the specific SC-code mainly due to the TRACER-structure • Some minor adaptions to the main COSMO code • Further adaptions to the specific MAKEFILE for compiling COSMO-SCM • The adaptions of the main COSMO code are within a test code ready for version 5.1 • SC-runs using COSMO-version 5.0 are carried out by workers in the “renewable energy projects” at DWD, by myself and by Ines Cerenzia at ARPA-SIMC. • The future TURBDIFF-version for COSMO and ICON is being developed within this framework • Remaining work: • Specific SC-code as part of COSMO source code administration • Automatic MAKEFILE-generation • Updated documentation • Remarks: • The additional code of the SC framework is comprehensive and can’t be inspected completely • It has been designed to be a test-bed only and is not optimized with respect to performance and is purely sequential. • User support can’t be provided yet. COSMO-SMC May 2014 Matthias Raschendorfer

2. Release Planning for V 5.1 – test_version of UB and MR: • 3D-extensions for TURBDIFF within the concept of scale separation: • TKE-advection in terms of q=SQRT(2*TKE) [lprog_tke]; done by U. Blahak • Horizontal shear production of TKE and horizontal diffusion (including TKE) at least for isotropic diffusion coefficients [l3dturb] • Consideration of a separated horizontal shear mode itype_sher = 1 : no consideration 2 : additional TKE production by scale interaction 3 : additional horizontal mixing by large horizontal shear eddies • Adaptions of the turbulent length scale in case of grid boxes with a smaller horizontal extent compared to the surface distance [not yet tested] • All modifications can be (de)activated • First tests of the implementations by U. Blahak • Main effects are expected for higher horizontal resolution, around steep orography or within frontal zones (large horizontal gradients) • Positive impact possible for EDR-forecast (used by aviation) • Some minor modifications needed for SC runs and some bug-fixes. COSMO-SMC May 2014 Matthias Raschendorfer

3. Test of the TKE advection for itype turb=3 and 7 done by U. Blahak: X-Z-cut along the 2D flow, U = 10 m/s, stable stratication (ICAO-standard atmosphere). 40 levels up to 22 Km, dX = 1.1 Km, dt = 10 s after 2 minutes starting with the not filled TKE-box (40 m2/s2)

4. Test of horizontal diffusion and TKE advection for itype turb=3 done by U. Blahak: LES-run with dX = 200m, heating by 300 W/m2 Vertical velocity after 4 h forecast time Left: 1D-turbulence (and no TKE-advection), Right: 3D-turbulence (and TKE-advection)

5. Release Planning for V 5.1 – current ICON-version of microphysics: • Introduction of cloud-ice sedimentation (F. Rieper, G. Zängl): • Counteracts our too persistent cirrus clouds (also in graupel-scheme) [lsedi_ice] • With an modified formulation of sticking efficiency of cloud ice to snow [lstickeff] • Modifications have been tested in ICON • Reduction of overestimated ice water content • Impact on COSMO should be positive as well • Limitation of evaporation from falling precipitation (G. Zängl): • Avoids overshoots of evaporation within a time step towards super-saturation • Removes a source of numerical instability • Modification has been tested in ICON • Improved simulation of super-cooled water and some bug-fixes (by F. Rieper) • Liquid water sub layer on top of ice cloud layer due to ice sedimentation and a reduction of freezing rate of in-cloud and below-cloud water [lsuper_coolw] • Reduction of overestimated number of ice particle as a function of time • Much improved forecast of aircraft icing (for aviation) • Has been already been tested with COSMO (based on current version of microphysics) but not with ICON and not with the graupel scheme COSMO-SMC May 2014 Matthias Raschendorfer

7. Common COSMO-ICON TURBDIFF: • Preparation of COSMO to be compatible with ICON version • Interface providing variables in block-data structure and • Adaptions to modified subroutine structure • Wind components on mass positions • Calculation of 3D-shear including the treatment of separated horizontal shear • Adaptions to modified initialization of turbulent variables • Introduction of surface flux densities as global model variables • Various adaptions in order to use new generalized routine for vertical diffusion • Modifications of the ICON version • Inclusion of pre-calculated horizontal shear terms • Upgrade with respect to some further modifications based on the development code within COSMO-SC (still without block data structure) • Debugging, Testing and Verification of the upcoming code • Planned for COSMO-5.2 COSMO-SMC May 2014 Matthias Raschendorfer

8. Further improved microphysics/radiation: • Improved treatment of cirrus clouds (PhD of C. Köhler): • State of the art parameterization of ice nucleation (including homog. freezing) • Different treatment of depositional growth of cloud ice and snow • Considering ice sedimentation (already in current version) • Treating number concentration of activated ice nuclei as prognostic variable • Modifications have been tested in ICON (not yet satisfying, implementation bug?) • Reduction of overestimated ice water content • Planned for COSMO-5.2 • Improved cloud radiation coupling (U. Blahak, B. Ritter) • Optical properties of hydrometeors depending on their effective radius • Including snow, graupel and rain in the radiative calculations • Effective factor to consider subgrid scale variability within clouds • Radiative properties of SGS clouds • Consolidated test version implemented in COSMO 4.22 • Promising test results based on real cases • Planned for COSMO-5.2 COSMO-SMC May 2014 Matthias Raschendorfer

10. Short-term Priorities and Rlease-Planning: MS: priority of MeteoSwiss SP: Included in Science Plan AL: Included in short term Action List of turbulence meeting RD: Running Developmen TG: To be Transferred form GME NR: planned for Next Release at least some aspects (NR) contributors MS (NR) SP AL (MR, IC) RD (UB, JF) MS AL NR to be implemented in unified version SP MS AL NR MS RD AL (MR, UB) MS NR (MR) RD TG NR SP (CK, UB) MS (NR) SP RD (UB) MS TG MS NR (CK, UB) SP Super-cooled water and div. bug fixes by F. Rieper NR (CK, UB) COSMO-SMC Dec.2013 Matthias Raschendorfer

11. Common COSMO-ICON Physics: • Common TURBDIFF-module is being developed within the SC-framework: • A precursor of the ICON-implementation has been implemented into COSMO_5.0-SCM • Horizontal operations has been moved to the calling interface • Adaptions to TRACER-structure implemented • Outstanding: • Transfer of some development from COSMO test versions • Transition to block-data structure • Activation of the vertical diffusion procedure contained in TRUBDIFF • Transfer of some development that has taken place already in ICON • Saving the explicit surface fluxes from TURBTRAN or TERRA • … • Debugging, Testing and Verification of the upcoming code • Microphysics, SSO, TERRA (ICON-code has developed): • Only interface for long-parameter-list call and block-data structure • Convection, Radiation: • Different schemes in COSMO and ICON • Common modules -> Common library: content? Code management? COSMO-SMC Dec.2013 Matthias Raschendorfer

12. Turbulence meeting: working-plan: COSMO-SMC Dec.2013 Matthias Raschendorfer

13. PT ConSAT: COSMO-SMC Dec.2013 Matthias Raschendorfer

14. DWD-point of view: • At this stage of the implementations, it will be most efficient, if that the work is done by the originating developer. • The work should prepare a basis for further development shared within COSMO. • The guideline of further related work is given in the current PT-Plan and it is in accordance with the SP chapters on SAT and turbulence. • Nevertheless, before starting with the physical content even in the running ConSAT, the next most urgent steps belonging to “applied research” needs to be done: • merging different developing branches within common modules for COSMO and ICON, • preparing the SC-testbed [We already coordinated that kind of work at our November turbulence meeting.] • The coordination on WG-level is by far sufficient. By definition of future PTs along the longer-term plans, the work can be focussed onto clear tasks, which also offers FTE-level contributions. • Another administration level between that at the NWS and the WG-coordination seems not to be an advantage in this particular field, since it would call for further parts of my FTE for in principal dispensable duplication of writing plans and reporting. • Rather this would even delay progress, and I’m therefor obliged to organize the work as described. COSMO-SMC Dec.2013 Matthias Raschendorfer