COSMO General Meeting, 19 September 2007 WG 3: Status Report Marco Arpagaus COSMO General Meeting, 19 September 2007 Detailed status reports available on the COSMO web-site Acknowledgments: WG 3 members

WP 3.1: Boundary layer (turbulence and surface transfer scheme) 3.1.1: Revision of the transfer scheme together with the related documentation 3.1.2: Reorganisation of the turbulence scheme and implementation of the 3-d extension together with the completion of relevant documentation 3.1.3: Extensions of the SC framework 3.1.4: New concept for a roughness layer extension of the current turbulence scheme 3.1.5: Higher vertical resolution for the lowest part of the boundary layer (NN)

Revision of the near surface diagnosis (Raschendorfer; update) COSMO-EU: BL is too moist and too cold; despite this, T2m is too high at noon; this is particularly true for grid points with a large z0 and an unnaturally moist soil. Hypothesis: diagnosed T2m is too high if compared to SYNOP measurements, especially for grid-points with large z0; SMA 'corrects' for this by adding water to the soil, thereby moistening and cooling the BL; Problem of wrongly diagnosed T2m in COSMO-EU only visible when even a saturated soil can not correct the positive T2m bias Cure: Use z0 = 0.02 m for T2m diagnosis Additional changes to stability functions needed, especially for stable stratification

GME Verification of T2M: Routine, i. e GME Verification of T2M: Routine, i.e. z0=z0(grid average) for T2M diagnosis

GME Verification of T2M: Experiment, i. e GME Verification of T2M: Experiment, i.e. z0=z0(SYNOP station) for T2M diagnosis

WP 3.2: Grid-scale clouds and precipitation no regular WPs – but: Revision of microphysical parameterisation (cloud ice & graupel schemes) by Axel Seifert …  poster by Axel Seifert and Michael Baldauf on 'Explicit forecasting of deep convection with COSMO-DE' Supercell Detection Index Sensitivity to PBL Scheme (diurnal cycle of deep convection)

Sensitivity of the diurnal cycle to PBL assumptions: Sensitivity of the diurnal cycle to PBL assumptions: Precipitation frequency Hovmöller diagrams for Germany from 1 June to 21 July 2007 Radar Control run Less diffusive ‘dry’ PBL Now the radar observations show an even more pronounced diurnal cycle The current version of COSMO-DE is not able to reproduce this diurnal cycle A modified PBL scheme can help to get the diurnal cycle even on a 2.8 km grid Obviously the mass average is dominated by larger-scale events, therefore the frequency diagram ist better for looking at the air mass / orographic convection which is weaker than the forced convection.

WP 3.3: Convection 3.3.1: Implementation of Kain-Fritsch scheme

WP 3.4: Radiation 3.4.1: Cloud-radiation interaction 3.4.2: Improve radiation treatment at small mesh-sizes

WP 3.3: Convection WP 3.4: Radiation 3.3.1: Implementation of Kain-Fritsch scheme 3.4.1: Cloud-radiation interaction 3.4.2: Improve radiation treatment at small mesh-sizes ( Done! – WP is finished!)

WP 3.5: Lower boundary condition: soil and vegetation 3.5.1: Revision of external parameters for plants (NN) 3.5.2: Intercomparison of soil models in the framework of soil moisture validation  poster by Gerd Vogel More sensitivities studies by Felix Ament ( poster: Evaluating modifications of the soil module TERRA) and Alexander Block (CLM)

Soil moisture (3-9cm) Falkenberg site

Result II – Budget Summary Snow SM Evaporation Rain Surface Runfoff Intermediate Runfoff Ground Runfoff Result II – Budget Summary Runoff_s mm Runoff_g mm Runoff_m Evapo. DSM lE (JA) W/m2 CTL 440 359 196 621 4 93 Deviations in mm Reduced Runoff RIGID, GWATER Reduced interm. Runoff BROOKS1, BROOKS2 Reduced Evapo. (sustainable) NP89, VEGPARA, Z0LOC Little impact ROOTDIST, MACROPOR Problematic ECOVEG (dry out!) RIGID -1 -97 7 22 75 5 GWATER -29 3 1 BROOKS1 -21 20 -116 -6 -2 BROOKS2 -20 61 -128 -30 -11 -4 BROOKS3 - ECOSOIL 29 -22 -14 10 MACROPOR -12 2 -18 4 6 PEDO -9 54 -65 -34 -10 VEGPARA 32 13 -44 12 ROOTDIST ECOVEG 45 101 -118 17 NP89 66 -84 18 Z0LOC 25 9 -37 -3

Uncertainty ranges T2m daily temperature range Yearly average Monthly average

WP 3.x: Lower boundary condition: snow An advanced snow parameterization for the COSMO-model  poster by Ekaterina Machulskaya et al

WP 3.6: Lower boundary condition: lakes 3.6.2: Implementation of lake model into the LM  poster by Dmitrii Mironov Done! – WP is finished! Flake is ready to be used! Flake is very popular (HIRLAM, UM, Météo-France, ECMWF, …)

WP 3.7: Lower boundary condition: urban areas 3.7.1: Urban turbulence parameterisation

WP 3.8: Lower boundary condition: mosaic and tiles 3.8.1: Implementation of mosaic approach

WP 3.9: Sub-km version 3.9.1: High-resolution numerical modelling of deep moist convection dynamics

WP 3.10: Validation and related matters 3.10.1: Single column model studies 3.10.2: Development of a tool for extended parameter determination (NN)

WP 3.11: Efforts to cure observed model deficiencies 3.11.1: Improve diagnosis of convective and turbulent gusts (NN) 3.11.2: Investigate reason for cold/moist bias in PBL

WPs 3.7 to 3.11 3.7.1: Urban turbulence parameterisation 3.8.1: Implementation of mosaic approach 3.9.1: High-resolution numerical modelling of deep moist convection dynamics 3.10.1: Single column model studies 3.10.2: Development of a tool for extended parameter determination (NN) 3.11.1: Improve diagnosis of convective and turbulent gusts (NN) 3.11.2: Investigate reason for cold/moist bias in PBL

Priority projects Towards a Unified Turbulence-Shallow Convection Scheme (‘UTCS’; PL: Dmitrii Mironov)  talk by Dmitrii Mironov Note 1: Need (much …) more individual initiative from project participants! Note 2: Need a (much …) better idea of the individual tasks! Tackle deficiencies in precipitation forecasts (‘QPF’; PL: Marco Arpagaus)  talk by Silke Dierer