5th wrf lsm workshop, ncar, 9/13/05 overview of the unified noah lsm in wrf recent enhancement,...
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5th WRF LSM Workshop, NCAR, 9/13/05
Overview of the Unified Noah LSM in WRF Recent Enhancement, Test, and Future Plan
Fei Chen
Research Application Laboratory, NCAR
NCARKevin ManningMukul Tewari Jimy DudhiaDave Gochis
Peggy LeMone
NCEPKen MitchellMichael Ek
AFWAJohn EylanderJerry Wegiel
NRLTeddy Holt
UniversitiesDev Niyogi (Purdue)
Eric Small (CU)Venkat Laskhmi (USC)Alexis Lau (HKUST)
Other InstitutionsHiroyuki Kusaka (CREPI, Japan)
Bill Coirier (CFD Res. Corp)
5th WRF LSM Workshop, NCAR, 9/13/05
WRF R&D aims
Priority for 1-10 km grid applicationsAdvanced data assimilation and model physicsPortable and efficient on parallel computers
Well-suited for a broad range of applications
Community model with direct path to operations
5th WRF LSM Workshop, NCAR, 9/13/05
Development and Implementation of the Community Noah Land Surface Model
• Collaborative Noah LSM development effort: NCEP, NCAR, U.S. Air Force Weather Agency, university community
• Support WRF mission and community requirements for high-resolution forecast of:– Severe weather (flash flooding) – Air pollution, transport and dispersion of toxic chemicals– Conditions affecting surface and air transportation– Extreme-temperature in the energy/utility industry
loading– Agricultural applications (irrigation management, pest
control)
5th WRF LSM Workshop, NCAR, 9/13/05
Mission
• Integrate advance land models/modules, new data sets, and land data assimilation techniques to improve representation of land and boundary layer processes in WRF
5th WRF LSM Workshop, NCAR, 9/13/05
Major Milestones in WRF/LSM Efforts
• SI include background fields (FY 2001): – 30-second global USGS 24-category landuse map– 30-second global hybrid (30-sec for CONUS and 5-min elsewhere) top and
bottom soil texture– 1-deg annual mean air temperature as lower boundary temperature for soil– NESDIS 0.144-deg monthly 5-year climatology green vegetation fraction– NESDIS 0.144-deg monthly 5-year climatology albedo
• SI Initialize soil moisture, temperature, snow, and sea-ice from AVN and Eta/EDAS (FY 2001)
• Implementation of OSULSM (WRF release 1.2 Beta, FY 2001)
• Inclusion of OSULSM for idealized WRF cases (available for mass version, FY 2001)
5th WRF LSM Workshop, NCAR, 9/13/05
Major Milestones in WRF/LSM Efforts
• Since 1 Dec. 2001: WRF/OSULSM coupled model has been running in real-time at NCAR
• SI add capability to read ARGMET soil fields as initial land state conditions (FY 2002)
• Implementation of FSL RUC LSM (FY 2002)• NCEP group delivers the quasi-unified Noah LSM for
internal test (FY 2002)• SI add nearest neigh approach for interpolation of external
landuse and soil texture, and land state variables (FY 2002)
5th WRF LSM Workshop, NCAR, 9/13/05
Major Milestones in WRF/LSM Efforts• Implement new surface driver (FY 2003)
– Separated from PBL driver
• SI add Maximum snow albedo database (FY 2003)• Implement quasi-unified Noah LSM (FY 2003)
– Snow and frozen-ground physics– Soil thermal conductivity– Patchy snow cover– Snow density– Soil heat flux treatment under snow pack– Snow roughness length
5th WRF LSM Workshop, NCAR, 9/13/05
Major Milestones in WRF/LSM Efforts• Implement the unified Noah LSM in WRF 2.0 and set up
CVS for Noah support (FY 2004) • Enhance the unified Noah LSM (FY 2004)
– Seasonal varying surface emissivity– Simple urban landuse treatment
• Apply high-resolution land data assmilation (HRLDAS) to ARW realtime 5-km winter and 4-km summer experiments
• Land surface models currently in test (FY 2004)– CLM– Pleim-Xu LSM – Single layer urban canopy model (close to be released)
5th WRF LSM Workshop, NCAR, 9/13/05
Provide documentation for the unified Noah LSM for its offline and coupled application
The unified Noah LSM significantly improved the precipitation scorecompared to its predecessor OSULSM
Realtime 22-km CONUS 12Z Cycle initialized from 40-km EDAS
12 day 12-36 h forecasted rainfall from 15 to 31 May 2003 verified on #212 grid
Unified Noah LSM
OSULSM
Precip scores availableat NSSL website
WRF/Noah Snow Forecast CapabilitySnow Storm Case 18 March 2003
24-h snow water equivalent change valid at 06Z 19 March
Analysis: 24-h SWE change valid at 06Z 19 March
Snow meltedtoo quickly inthe OSULSM
accumulationmelt/sublimation
WRF/Noah more realistic snow forecast
5th WRF LSM Workshop, NCAR, 9/13/05
Landuse Based Verification for 15 June 2005
2m Temperature Wind Speed
RED: Dryland Cropland, Blue: Cropland, Black: GrasslandGreen: Shrubland, Yellow: Evergreen Needleleaf Forest
High-resolution Land surface and urban modeling and assimilation system
Vegetation type
Soil texture
Urban type
Terrain
snow
Vegetation cover
Leaf area index
High resolution land data assimilation system (HRLDAS)
Obs. PrecipitationRadiation, T, Q, U, V
Soil moisture, soil temperature, snow cover, canopy water, wall/roof/road temperature
Noah land surface model, Urban canopy model
Boundary layer parameterization Coupled mode
HRLDAS Spin-Up
Sensible heat flux Latent heat flux
≤ ≤5 5 < 10 10 <Surface heat flux RMS difference (Wm-2)
Coarsesoil
Medium soil
Fine soil
Hovmoller Diagrams of Rainfall on 4-km WRF GridTime: 12Z 9 June - 12Z 21 June 2002 Longitude: from 107 W to 86 W
Continuously cycled soil moisture Updated daily with HRLDAS soil Difference (HRLDAS-Cycled)
Both experiments able to simulate propagating convection. Soil conditions influence timing of location of storm origin.
5th WRF LSM Workshop, NCAR, 9/13/05
Some solutions: Dynamic modeling of land-Some solutions: Dynamic modeling of land-surface hydrology with ‘surface hydrology with ‘Noah-RouterNoah-Router’’
(NCAR Tech Note: Gochis and Chen, 2003)(NCAR Tech Note: Gochis and Chen, 2003)
2-Dimensional2-DimensionalDiffusive WaveDiffusive Wave
Overland Flow RoutingOverland Flow RoutingOgden, 1997Ogden, 1997
Saturated Subsurface RoutingSaturated Subsurface RoutingWigmosta et. al, 1994Wigmosta et. al, 1994
Ponded Water EvaporationPonded Water Evaporationand Re-infiltrationand Re-infiltration
Direct EvaporationDirect Evaporation
Re-infiltrationRe-infiltration
Surface Exfiltration fromSurface Exfiltration fromSaturated Soil ColumnsSaturated Soil Columns
Lateral Flow fromLateral Flow fromSaturated Soil LayersSaturated Soil Layers
5th WRF LSM Workshop, NCAR, 9/13/05
Terrain and Land-use of the Model Domain with 10-km grid spacing
1200km
Sea of Japan
Pacific Ocean
5th WRF LSM Workshop, NCAR, 9/13/05
Terrain and Land-use around Tokyo
Tokyo Metropolitan area
5th WRF LSM Workshop, NCAR, 9/13/05
2-m Temperature on 1500 LT: Obs and WRF (Case UCM)
5th WRF LSM Workshop, NCAR, 9/13/05
2-m Temperature on 0300 LT: Obs and WRF (Case UCM)
High-Resolution WRF/Noah/Urban Modeling Capability
Complex terrain on WRF nested D-5 (0.5 km grid spacing) over the Slat Lake City area Complex Urban land use
distribution over Salt Lake City
Single layer Urban Canopy Model
Domains: 40.5,13.5,4.5,1.5,0.5 km
High-Resolution WRF/Noah/Urban Modeling Capability: Coupled to CFD-Urban
WRF-Noah/UCM coupled model forecast
Down-Scale
Up- Scale
Coupling
•
CFD-Urban:Hi-Res Urban Model
Diurnal Wind Direction at North Downtown
NIGHT DAYRed: Obs, Green: WRF/Noah, Blue: WRF/Noah/UCM
5th WRF LSM Workshop, NCAR, 9/13/05
• Entire IOP 10
• 3 Releases/Pauses
• WRF Data for BC
•Quasi-steady approach:
• Wind/Turbulence fields at 15 minute intervals
• Unsteady T&D using Unified Frozen Hydro Solver
• Flow turning is replicated, which causes plume to travel NNW
WRF/UCM - CFD Transport and Dispersion Preliminary Results: Urban IOP 10 Urban 2000
5th WRF LSM Workshop, NCAR, 9/13/05
WRF/UCM - CFD Transport and Dispersion Preliminary Results: Urban IOP 10 Urban 2000
• Urban 2000: Field Test conducted in Salt Lake City
• SF6 released in Central Business District
• Samplers located in CBD and on “arcs” located downstream
•Statistical Comparison of Predicted to Measured Concentration Data
Acceptable values:
• FAC2 > 0.5
• -0.3 < FB <0.3 (0.7 <MG < 1.3)
• NMSE < 4 (VG <1.6)
5th WRF LSM Workshop, NCAR, 9/13/05
Preliminary Results: IOP 10 Urban 2000• Three sets of calculations:
• Raging Waters Input: Use sounding data (single sounding) at all boundary faces
• WRF Boundary Conditions: Unsteady Flow, Turbulence and Contaminant
• WRF Boundary Conditions: Steady Flow (“Wind Library”)Near Source R2 R3 R4 All
FAC2: RW 0.12 0.17 0.36 0.38 0.18FAC2: Unsteady 0.08 0.17 0.36 0.38 0.16FAC2: Quasi-Unsteady 0.57 0.42 0.36 0.5 0.51MG: RW 25.42 14.11 4.58 5.06 15.83MG: Unsteady 15.89 11.64 4.77 5.679 11.69MG: Quasi-Unsteady 0.74 1.59 1.96 2.05 1.04
• Quasi-Steady approach appears to be best mode of operation:
• Steady-state wind/turbulence fields at set intervals in time using WRF data as boundary conditions
• Significantly improve FAC2 (FAC>0.5 acceptable) and MG (0.7<MG<1.3 acceptable)
•Unsteady flow/turbulence/transport: Time step restrictions
•Too costly for accuracy or inaccurate because timestep too big
5th WRF LSM Workshop, NCAR, 9/13/05
Summary• We have achieved main tasks we set four years ago• Unified Noah LSM modifications currently tested at NCAR
– Vary LAI as landuse type and scale it by vegetation fraction– Define all vegetation parameters in VEGPRM.TBL (part of them are
now defined in LANDUSE/TBL) – Adjust parameters (emissivity, roughness length, albedo)
• Need to incorporate new satellite data • Further changes/improvements brought up at the workshop• Need more systematic evaluation of coupled model (surface
heat fluxes, radiation, for instance) • Implement the unified Noah in NMM, AGRMET, COAMPS