1 / 38

AROME-France: NWP Activity for Model Upgrades

General overview and preparations for the Arome-1.3km 90 level configuration. Includes microphysics, turbulence, and new applications.

barmore
Download Presentation

AROME-France: NWP Activity for Model Upgrades

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AROME-France: a snapshot of NWP activity for model upgrades • General overview of Arome-France • Illustration of NWP activity: preparations for the Arome-1.3km 90 level configuration (forecast model aspects) • Longer term aspects: • Microphysics: 2-moment schemes • Turbulence: 3D effects • (there are more aspects, not discussed in this talk !) • New applications at MF, based on Arome

  2. AROME-France • Bi-Fourier spectral limited-area model with a semi-implicit, semi-Lagrangian timestep solver, and Laprise-type compressible dynamical equation in terrain-following hybrid mass coordinates • Operational since December 2008 • Resolutions : Dx=2.5km , 60 vertical levels, Dt=60s • 3D-Var with a 3h assimilation window • Hourly coupling to global ARPEGE model • 4 daily 30h forecasts at 0,6,12,18h UTC (750x720x60) Altitude (m) • Seity Y., P. Brousseau, S. Malardel, G. Hello, P. Bénard, F. Bouttier, C. Lac, V. Masson, 2011: The AROME-France convective scale operational model. Mon.Wea.Rev., 139, 976-991. • Brousseau P., L. Berre, F. Bouttier, G. Desroziers, 2011: Background error covariances for a convective scale data assimilation system: AROME 3D-Var. Quart. J. Roy. Meteor. Soc., 137, 409–422.

  3. AROME physical parameterizations

  4. Current operational use of radar data in assimilation • French ARAMIS network • 24 Doppler radars, 10 Polarimetric, between 3 and 12 PPIs in 15’ • Within AROME: • Volumic observations are considered every 3 hours • Radial wind from 15 radars since December 2008; from 22 radars since 24 November 2010 – Triple PRT leading to unambiguous velocity of 60 m/s • - Reflectivity from 24 radars since 6 April 2010 C Band Polarimetric S Band

  5. Observations in AROME-France 3D-VAR DOW Z DFS (rain +) DOW Z RADARS AIRCRAFTS SYNOP/RADOME IASI SEVIRI TEMP Ground GPS DFS (rain +++)

  6. Recent results of objective evaluation • Courtesy by the monitoring team in MF (COMPAS/ J. Stein and I. Sanchez)

  7. Results of fuzzy probabilistic evaluation for precipitation of AROME

  8. AROME-France: Preparation of a higher (horizontal and vertical) resolution version, illustration of R&D studies and evaluation courtesy by F. Bouyssel and Y. Seity

  9. AROME orography 1.3km (1440x1536 points) AROME 2.5km (750x720 points) From GTOPO30 1 km From GMTED2010 250m Horizontal grid of AROME-France 1.3km • New model domain will be slightly increased to the North

  10. Zoom_Savoie_1.3km : Grenoble Grenoble Bourg d’Oisan Zoom over the Alps • Deeper valleys, higher mountains (« river deep, mountains high ») Zoom_Savoie_2.5km :

  11. Vertical grid AROME-France 1.3km L90/L60 : smooth increase of vertical resolution throughout PBL

  12. AROME-France 1,3km : re-tuned parameters and options in the model’s dynamics • CY40_op1 / oper 38t1_op1

  13. AROME-France 1,3km : re-tuned options in the model’s physics • Specific changes to improve the model behaviour from 2.5km to 1.3km: • 1) Microphysics (modification of the threshold value for autoconversion of snow) • 2) Surfex (surface scheme): • - version update (v6+ -> v7.2), • - retuned orographic drag (because of the lower first model level), • - SBL (CANOPY) scheme deactivated over land.

  14. Wintertime fog Repeated problems observed with winter fog; studied in collaboration with Hungary (E. Bazile, Y. Seity, B. Szintaï). The low level Stratus cloud dissipates in the AROME forecast, when it remains over the daytime in reality. ARPEGE AROME

  15. Wintertime fog Observed behaviour: AROME generates more snow on the ground than ARPEGE. AROME ARPEGE Studying budgets of various processes, it was noticed that snow in AROME forms after ice droplets form by condensation of water vapour, and are changed to falling snow by autoconversion

  16. Wintertime fog Changing the critical threshold of autoconversion, AROME better keeps the fog in its forecast. AROME Reference qi0=0.2E-4 AROME with qi0=1E-3 -> for AROME-1.3km, qi0=0.2E-3 was chosen -> there seems to be no (deteriorating) impact of this change on summer or winter cases of precipitation

  17. Switch off SBL (Canopy) over land AROME_1.3km / AROME_1.3km without SBL over land. RMS bias The periods where AROME-1.3km without SBL is better than the reference rather correspond to anticyclonic (high pressure) situations over France.

  18. Evaluation of model performance other than by scores or case studies: Automatic detection of convective cells 21 June 2012 : 41dBz 1.3 km: nb of small convective cells increased and nb of big cells decreased 1.3 km: closer to observed radar reflectivity Strong impact of semi-lagrangian horizontal diffusion (not shown) Small impact of spectral diffusion and time-step (not shown) (J. Léger, D. Ricard, Y. Seity)

  19. AROME-France 1,3km: System aspects • Optimisations: • I/O server (P, Marguinaud) • MesoNH physics are now called with the same vertical level ordering than ARPEGE • Bottom and top additional points (KLEV+2) no more necessary except for turbulence (-> cleaning of apl_arome) • About 274 nodes of our Bull ( > 1/4 of the machine) will be required to perform AROME 1,3 km 24h forecast in 30' (with mixed MPI/OpenMP parallelisation) • Preparation of initial surfex file has been MPI parallelised (provided that an FA PGD file is used as input).

  20. AROME-France: Longer term perspectives Courtesy by Y. Seity, F. Bouyssel, Y. Bouteloup, R. Honnert

  21. Microphysics • Beyond the picture above => R&D ongoing effort: Hail • Tests in AROME with new version of ICE-scheme (ICE4 v/s ICE3) showed that new scheme produces too frequently hail, with too low intensity • Work in progress in the mesoscale Research group for improving ICE4 • In the meanwhile: a diagnostic computation of hail, derived from vertically integrated content of graupel, has been implemented in AROME-France • Within a few years from now: move from a 1-moment scheme (mass of each hydrometeor class per kg is evaluated) to a 2-moment scheme (mass of each class + concentration or number of droplets per class)

  22. New microphysics scheme : Liquid Ice Multiple Aerosols (LIMA) = a 2-moment microphysics scheme developed in Meso-NH in order to improve the modelling of the complex { aerosol – cloud – precipitation } interactions Pristine Ice Cloud droplets Activation / Nucleation Impaction scavenging Precipitations Aerosols (CCN & IFN) Radiative effect Transport Cloud dynamics B.Vié, J.-P. Pinty

  23. New microphysics scheme : Liquid Ice Multiple Aerosols (LIMA) • Prognostic 3D variables in LIMA • Mixing ratios (kg.kg-1) : rC, rR, rI, rS, rG • Concentrations (kg-1) : NC, NR, NI  NEW • Aerosol concentrations (kg-1, for each mode) : NFree, NActivated  NEW • New / Modified processes compared with ICE3 • Activation / nucleation of aerosols • Impaction scavenging of aerosols by rain • More physical representation of autoconversion. • Over-saturation is supported more easily than in ICE3 • ICE4 / ICE3 cold processes concerning hail/graupel remain the same • (-> improvements in ICE4 scheme will automatically benefit to LIMA).

  24. LIMA : Aerosols initialisation MACC Sulfate • LIMA aerosol population • (Number concentrations (kg-1) !) • CCN • Coated IFN • IFN MMR kg.kg-1 Sea salt (3 bins) Sulfate Hydrophilic OM Sea salt Hydrophobic OM Hydrophilic BC Hydrophilic OM/BC Hydrophobic BC Hydrophobic OM/BC Dust (3 bins) Dust

  25. First real case test : HyMeX IOP 6 – 24 sept. 2012 18-h accumulated rainfall (mm), 12UTC : Observations: 45N 45N 5E 5E LIMA ICE3 Technically working in the community Research model Méso-NH, Validation/tuning will continue (HYMEX observations) Brainstorming on its implementation in AROME will start in autumn 2014 (numerical efficiency -> simplifications in the code, time stepping)

  26. Turbulence: subgrid scale mixing • Homogeneous (3D) small scale vortices: turbulence • With a larger vertical extension (clouds or not): shallow convection • Deep convection (Cb clouds)

  27. Equation for turbulent mixing: 1D (vertical) • Tendency of a given field  as a mean over the full model grid cell: • Exchange coeff. Depends on TKE (local measure of subgrid variance of 3D kinetic energy) • Prognostic equation of TKE: • M: mass flux approach => specific closure assumptions (a family of parametrizations) • As a sub-product, computation of gusts (at 10m height, per gridpoint « i », MaxVal over the last 1h,  is calibrated w/r to observed values):

  28. Turbulence 3D ?

  29. Turbulence 3D ?

  30. Other NWP applications based on AROME (MF plans for 2015-2016)

  31. AROME-France RMS error for 2m temperature AROME-nowcasting Forecast range (hours) Comparaison AROME-France AROME-nowcasting for 2m temperature AROME-Nowcasting AROME-Nowcasting under development (operational in 2015) AROME 1.3km : 6h forecast every hour based on 3DVar analysis with 15min cut-off Boundary conditions are re-computed every hour from our AROME-France model. No cycling so far and no specific surface data assimilation. • The scores are better for most of the parameters. • Surface pressure is worse in the 3 first hours of run, then is better, this illustrates the spin-up impact. • After 3 hours the improvement is weak

  32. AROME Ensemble Prediction System • AROME EPS is under development (operational in 2015) • AROME-France members running every 6 hours to ~40-h range • ~10 members at 2.5km resolution (vs 1.3km for deterministic AROME-France beginning 2015) • Perturbations: • initial upper-air: rescaled & centered perturbations from global PEARP ensemble (with 8km local resolution) • initial surface: correlated random perturbations of SST, soil moisture/humidity, snow, physiography datasets • lateral boundary conditions: 10 members selected from the 35-member PEARP ensemble (by clustering) • model error: SPPT (stochastic perturbation of physics tendencies), similar to ECMWF EPS • Current research: • calibration, verification of radar reflectivity, validation in context of hydrology & air traffic management • study of forecast error correlations & coupling with EDA

  33. 31-01-2013 (+14h)

  34. SESAR EU project: AROME-airport system • AROME hourly assimilation at 2.5km using AROME-France forecast as first guess (on red domain) : two additional wind profilers • AROME forecast at 500m performed on green domain to produce boundary conditions to a Wake-Vortex prediction model RMSE of wind force for: AROME-France (green) AROME-airport 2.5 km (red) AROME-airport 500m (blue) X-axis is the forecast range in hours. Areas covered by the models, AROME-airport 2.5km domain (red) AROME-airport 500m domain (green) Zoom of an AROME-airport 500m forecast, vectors show wind direction and force, shaded areas is orography.

  35. sunom bitti. İlginiz için teşekkür ederim

  36. Preparation of AROME future configurations • Preparation of an increase of spatial resolution planned for AROME-France NWP system : ~1.3 km and ~90 vertical levels. • Development of a nowcasting system based on AROME NWP model at 1.3km with hourly assimilations and short range forecasts (few hours) • Development of a convective scale ensemble forecasting system based on AROME NWP model at 2.5km • Evaluation of AROME-500m over dedicated areas (airports, mountains, ...) : case studies of heavy precipitation and mountains waves, wake vortex dissipation over airport (SESAR European project)

  37. AROME1.3kmL90 HRV observation AROME2.5kmL90 AROME2.5kmL60 Arome-1.3km: 31-01-2013 (+14h) Low level cloudiness AROME

  38. LIMA : Aerosols – clouds interactions • CCN activation is based on Cohard and Pinty (2000) • Extended to handle a multimodal aerosol population • IFN heterogeneous nucleation is based on Phillips (2008) • Experimental measurements of ice nucleation • 3 species of IFN : dust, black carbon, organic matter • Coated IFN • First activated as CCN to form cloud droplets • Same nucleation parameterization as insoluble IFN • Better representation of microphysical processes • Explicit deposition/sublimation rates, ice → snow conversion...

More Related