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)

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 layersLand use: Ecoclimap at 1km resolution (Masson et al., 2003)

50% great plains crops and 50% rockies grasslandtotal vegetation fraction over the pixel = 0.73

root depth = 1.5m and total depth = 2m leaf area index = 1.46CLAY=0.24, SAND=0.38 from Harmonized World Soil Database (HWSD) at 1km resolution

RN

H LE

G

SURFACE ENERGY BUDGET (W/m2)SURFACE ENERGY BUDGET (W/m2)

CPL more humid (e and LWD large)

INT TURBINT RAD

Steeneveld et al 2006

M10m (m/s)

T2m (K)

T (10m) – T (2m)

TIME SERIESTIME SERIES

Q2m (kg/kg)

SCM – STAGE 1B SCM + SURFACE – STAGE 2

SCM – STAGE 1B SCM + SURFACE – STAGE 2

VEGETATION ROOT DEPTH

default 50% bare 50% vegetated

sfc=1cm, root=1.5m, total=2m

BARE 100% bare0 % vegetated

sfc=1cm, root=1.5m, total=2m

ROOT 50% bare50% vegetated

sfc=1cm, root=0.4m, total=0.6m

SENSITIVITY TESTSSENSITIVITY TESTS

LATENT HEAT FLUX (W/m2)

TESTING THE SURFACE SCHEMETESTING THE SURFACE SCHEME

SENSIBLE HEAT FLUX (W/m2)

RN (W/m2)

TESTING THE SCM modelTESTING THE SCM model

RN

LE

H

TESTING THE SCM modelTESTING THE SCM model

10m wind speed (m/s)

2m specific humidity (kg/kg)

2m temperature (K)

SCM CPL CPL (BARE GROUND) CPL (ROOT DEPTH)

SENSITIVITY TESTSSENSITIVITY TESTS

WIND SPEED(m/s)

WIND SPEED(m/s)

TKE(m2/s2)

SCM CPL CPL (BARE GROUND) CPL (ROOT DEPTH)

SENSITIVITY TESTSSENSITIVITY TESTS

POT. TEMPERATURE(K)

<w'T'>(Km/s)

SCM CPL CPL (BARE GROUND) CPL (ROOT DEPTH)

SENSITIVITY TESTSSENSITIVITY TESTS

SPEC. HUMIDITY(kg/kg)

<w'q'>(kg m/s)

SENSITIVITY TESTS SENSITIVITY TESTS vertical resolutionvertical resolution

default: 85 levels (3m at lower levels)test: 60 levels (10m at lower levels)

SENSITIVITY TESTS SENSITIVITY TESTS vertical resolutionvertical resolution

60 levels 85 levels (DICE)

wind speed (m/s)

potentialtemperature(K)

SUMMARY

1) SCM vs CPL * CPL is giving larger LE and smaller H than SCM

* T colder in CPL than in SCM although there are no significant differences on the wind speed

* CPL has more specific humidity than SCM

2) reducing the percentage of vegetation * 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 than CPL or other tests* the humidity is reduced and the T2m is warmer than CPL, departing

from obs* the wind speed is not largely affected

4) vertical grid mesh* importance to properly reproduce the surface layer characteristics

QUESTIONS

1) Are there other surface parameters that might be interesting to check if they have realistic values?

2) Differences between models (CPL run)* surface characteristics* SCM parameterizations* which one is playing the most relevant role?

3) running all the models with the same surface parameters?Stage 1b: evaluating SCMStage 4(?): evaluating LSM

4) ...

ACKNOWLEDGEMENTS

RESEARCH PROJECT CGL2012-37416-C04-01

JAE-DOC contract