Evaluation of regional climate simulations with WRF model in conditions of central Europe Jan Karlický, Tomáš Halenka, Michal Belda, (Charles University in Prague, Czech Republic)

2 Contents 1. Sensitivity test of radiation and convection model parameterization 2. Evaluation of model simulations at mother domain, at sub- domain with one-way nesting procedure and at sub-domain without nesting 3. Comparison of hydrostatic and non-hydrostatic WRF version at the sub-domain with nesting procedure

3 Contents 1. Sensitivity test of radiation and convection model parameterization 2. Evaluation of model simulations at mother domain, at sub- domain with one-way nesting procedure and at sub-domain without nesting 3. Comparison of hydrostatic and non-hydrostatic WRF version at the sub-domain with nesting procedure

4 WRF (v. 3.3) model configuration  Domain: 25 km resolution, center point 50°N,13°E, 190 x 206 gridpoints  Input data: ERA-40, 0.5° resolution  Validation: E-OBS reference data, 0.25° resolution  Model setting: ptop = 5000 Pa, 28 vertical levels, time step 200 s, recommended WRF setting for RCM: PBL – YSU scheme, Noah Land Surface Model, surface layer – MM5 scheme, microphysics – WRF single moment 6 class  Tested schemes of radiation transfer: RRTM (LW), Goddard (SW), CAM (LW+SW, recommended)  Tested schemes of convection: Kain-Fritsch (recommended), Grell-Devenyi, Tiedtke

5 Parameterization test, full-area averages for years 1991– 2000 (WRF – E-OBS 5.0)  Chosen combination – RRTM+Goddard (rad.) +Tiedtke (con.)

6 Contents 1. Sensitivity test of radiation and convection model parameterization 2. Evaluation of model simulations at mother domain, at sub-domain with one-way nesting procedure and at sub-domain without nesting 3. Comparison of hydrostatic and non-hydrostatic WRF version at the sub-domain with nesting procedure

7 Nested domain configuration  Domain: 6.25 km resolution, 181 x 121 grid points (white rectangle )  Driving data: 25 km WRF simulation (nesting procedure), ERA-40 (without nesting)  Time interval 1961–1970, 1960 spin-up  Parameterization: RRTM+Goddard (radiation), Tiedtke (convection)

8 Comparison of simulations on sub-domain Temp., rainfall (sub-domain area averages)

9 Comparison of simulations on sub-domain Temp., rainfall (spatial distribution) 6.25 km nested simulation 6.25 km direct simulation T2 MEAN RAINFALL DJF MAM JJA SON

10 Contents 1. Sensitivity test of radiation and convection model parameterization 2. Evaluation of model simulations at mother domain, at sub- domain with one-way nesting procedure and at subdomain without nesting 3. Comparison of hydrostatic and non-hydrostatic WRF version at the sub-domain with nesting procedure

11 Comparison of hydrostatic and non-hydrostatic WRF Temp., rainfall (sub-domain area averages)

12 Comparison of hydrostatic and non-hydrostatic WRF T2 mean, rainfall (spatial distribution) T2 MEAN RAINFALL hydrostatic versionnon-hydrostatic version DJF MAM JJA SON

13 Downward SW radiation – model outputs vs. GEBA station data

14 Temporal distribution of precipitation Number of days > 0.1 mm Number of days > 10 mm hydrostatic versionnon-hydrostatic version DJF MAM JJA SON

15 Conclusions  Combination of schemes RRTM (LW radiation), Goddard (SW radiation) and Tiedtke (convection) makes the best results  Simulation on sub-domain performed directly from ERA-40 makes less temperature bias, precipitation impacted by prevailing flow  Non-hydrostatic version makes a little bit better results than hydrostatic on 6.25 km, but the difference is much less than general biases

16 Acknowledges  NCAR/UCAR – WRF ARW model  ECMWF – ERA-40 data – model boundary conditions  ECA&D – E-OBS reference data  ETH Zurich – GEBA (Global Energy Balance Archive) – radiation station data  GAUK (Grant Agency of Charles University) – financial support