1. THE EFFECT OF THE SURFACE CHARACTERISTICS ON THE DICE RESULTS SEEN BY THE MESONH MODEL M. A. Jiménez, P. Le Moigne and J. Cuxart DICE workshop, 14-16 October 2013, Exeter (UK)

2. DIurnal land/atmosphere Coupling Experiment (DICE) CASES – 99 experiment: 23-26 October 1999 released May 2013, preliminary results October 2013 Photograph taken at the CASES-99 experiment (Southern Great Plains, USA)

3. ModelContact scientist InstituteStages submitted LevelsSensitivity tests AromeEric BazilleMeteo FranceAll60/70resolution ArpegeEric BazilleMeteo FranceAll60/70resolution ECEARTHReinder RondaWageningenSCM only91LAI GDPS3.0Ayrton ZadraCMCAll79 GFDLSergey MalyshevPrincetonAll24 GISS_E2Ann Fridlind, Andy Ackerman GISS All40 IFS/HTESSELIrina Sandu, Gianpaolo Balsamo ECMWFAll137LAI MESO_NHMaria A. Jimenez, Patrick Le Moigne, Joan Cuxart IMEDEA, Meteo France, UIB All85Bare soil, rooth depth UM/JULESAdrian Lock, Martin Best Met OfficeAll70Vegetation WRF-NOAHWeiguo WangNUISTAll60Lots! WRFWayne AngevineNOAA?119PBL scheme CAM5, CLM4David LawrenceNCAR1a, 1b? PBCMPierre GentineColumbiaNot yet MODEL PARTICIPANTS

4. Stage 1b H, LE, RN, LST Atmosphere- SCM Surface - prescribed Stage 1a ISBA (3 layers) Atmosphere - prescribed Surface - SURFEX T,wind,q at 55m T,wind,q at 10m Stage 2 SCM + SURFEX (coupling) Stage 3 As Stages 1a and 1b but prescribing 12 different forcings (SCM and SURFEX) Atmosphere- SCM Surface - SURFEX

5. INITIAL CONDITIONS wind speed (m/s) potential temperature (K) specific humidity (g/kg) SCM - INITIAL PROFILES (sounding at 12 LT, 1900 UTC) T Q WIND LSM - INITIAL CONDITIONS (evolution of T, q and wind during the simulated period)

6. SCM: MesoNH model ( Lafore et al., 1998 ) Turbulence ( Cuxart et al., 2000 ), length scale ( Bougeault and Lacarrere 1989 ) Radiation (ECMWF code called every time-step) Kessler microphysical scheme (vapor, cloud water and rain) Time step (300s for SCM and 20s for coupled runs) Vertical grid ( Cuxart et al., 2007 ): 85 levels (3m resolution at lower levels, gradual stretching) LSM: SURFEX ( Masson et al., 2013 ) ISBA 3 layers Land use: Ecoclimap at 1km resolution (Masson et al., 2003) 50% great plains crops and 50% rockies grassland total vegetation fraction over the pixel = 0.73 root depth = 1.5m and total depth = 2m leaf area index = 1.46 CLAY=0.24, SAND=0.38 from Harmonized World Soil Database (HWSD) at 1km resolution

7. RN H LE G SURFACE ENERGY BUDGET (W/m2) INTTURBINTRAD Steeneveld et al 2006

8. M10m (m/s) T2m (K) TIME SERIES Q2m (kg/kg) observations in green * the wind speed is well captured * differences in T of 4-5K during day/night but CPL match better to the observations * CPL run too humid → large LE

9. SCM – STAGE 1BSCM + SURFACE – STAGE 2 LLJ well captured-> large-scale advection CPL run too humid

10. SCM – STAGE 1BSCM + SURFACE – STAGE 2 H larger LE smaller T warmer (lower levels) H smaller LE larger T colder (lower levels)

11. VEGETATIONROOT DEPTH default 50% bare 50% vegetated sfc=1cm, root=1.5m, total=2m BARE 100% bare 0 % vegetated sfc=1cm, root=1.5m, total=2m ROOT50% bare 50% vegetated sfc=1cm, root=0.4m, total=0.6m SENSITIVITY TESTS

12. LATENT HEAT FLUX (W/m2) TESTING THE SURFACE SCHEME SENSIBLE HEAT FLUX (W/m2) RN (W/m2) observations in red, equivalent to SCM SCM = root depth SCM = bare soil

13. TESTING THE SCM model RN LE H SCM = root depth SCM = bare soil SCM results (1b) agree with SURFEX results (1a)

14. TESTING THE SCM model 10m wind speed (m/s) 2m specific humidity (kg/kg) 2m temperature (K) observations in blue * no impact on the wind speed * impact on the T and q * q(bare ground) similar to obs.

15. SENSITIVITY TESTS vertical resolution (SCM, Stage 1b only) default: 85 levels (3m at lower levels) test: 60 levels (10m at lower levels)

16. SENSITIVITY TESTS vertical resolution 60 levels 85 levels (DICE) wind speed (m/s) potential temperature (K) 1-2 K difference

17. RN H LE Stage 3a results (SCM) 12 forcings as stage 1b hight & low values

18. Preliminary results Stage 1b (near surface evolution) 20m55m

19. Preliminary results Stage 1b (potential temperature)

20. SUMMARY 1) SCM vs CPL * CPL is giving larger LE and smaller H than SCM * CPL has more specific humidity than SCM 2) reducing the percentage of vegetation * Improve LE and H become closer to observations * As a test case, bare ground soil is taken but this is far from the reality... 3) reducing the root depths to a more realistic values * Improve H and LE is closer to observations * more realistic case, by default the root depth is too high 4) vertical grid mesh * importance to properly reproduce the surface layer characteristics

21. DICE site EASY CASE! surface and tower observations (model validation) clear-skies, flat, homogeneous, … SURFACE CHARACTERISTICS in the model covered by dry vegetation But still difficult for models … (introduce the concept of died vegetation)

22. ACKNOWLEDGEMENTS RESEARCH PROJECT CGL2012-37416-C04-01 JAE-DOC contract