1 RUC Land Surface Model implementation in WRF Tanya Smirnova, WRFLSM Workshop, 18 June 2003

2 Part 1: Current and Future Initialization of WRF Land States at FSL

3 Goal for use of WRF in the Rapid Update Cycle Use WRF model in Rapid Update Cycle (or Rapid Refresh) application at NCEP First step – test WRF model against current RUC hydrostatic model using common RUC initial conditions WRFRUC – WRF initialized with RUC-20 initial conditions, full-resolution native  coordinate data, including 3-d hydrometeor, land-sfc data

4 NCAR mass-coordinate dynamic core - v vertical sigma-p levels Initial conditions including land states for WRFRUC - native coordinate data from FSL RUC20 cycle including assimilation of observations not yet used in NCEP operational RUC20 – Coupled Data Assimilation System (CDAS) – available for outside users from the FSL ftp site in GRIB format Lateral boundary conditions from the same FSL RUC20 48h forecast RUC post-processing adapted to WRF output to produce RUC look-alike GRIB output WRFRUC model configuration

5 RUC CDAS - four-dimensional system (funded by GAPP) Uses a forward full-physics model Cycles surface/soil fields depending on the RUC atmospheric forcing Cycles 5 hydrometor species : cloud, ice, rain, snow and graupel. Cloud clearing/building based on GOES data New compared to RUC operational – 1.Forecast length (48-hour forecasts with hourly outputs) 2.Assimilation of: NEXRAD Radar reflectivity observations GPS precipitable water Boundary-layer profilers Mesonet observations collected at FS Main Goal: to improve 1-h precipitation forcing and the land surface model climate

6 24-hour precipitation accumulation ending at 1200 UTC 6 May 2003 RUC Control RUC CDAS Stage IV Rainfall

7 Spatial Correlation fields of 24-h Accumulated Precipitation ending at 1200 UTC 6 May 2003 (Dongsoo Kim) RUC CDAS RUC Control

8 Western US Diurnal cycle of biases from RUC control and RUC CDAS averaged for the period 1 December – 1 March m dew point 2-m temperature Western US

9 Two WRFRUC systems run at FSL in real time: 1.WRFRUC with 10-km horizontal resolution for the TAQ (Temperature and Air Quality) project - 48-hour forecasts twice a day (00 and 12 UTC, runs on JET since June 2002) 2. WRFRUC with 20-km horizontal resolution on CONUS domain - 24-hour forecasts twice a day (00 and 12 UTC, runs on JET since February 2003) - real-time fields

10 Physics options used in WRFRUC at FSL: - NCEP 5-class microphysics scheme (option 4) - RRTM longwave radiation (option 1) - Dudhia shortwave radiation (option 1) - Mellor-Yamada-Janjic Monin-Obukhov surface layer (option 2) - RUC land-surface model (option 3) - Mellor-Yamada-Janjic TKE scheme (option 2) - Kain-Fritsch (for CONUS) and Betts-Miller - Janjic (for TAQ) cumulus parameterization (option 1, 2) as of May 2003

11 Schematic presentation of processes included into RUC-LSM 6 levels in soil – 0, 5, 20, 40, 160, 300 cm State variables - volumetric soil moisture, soil temperature, snow cover/depth/temperature - cycled in RUC 1h cycle since 1997.

12 WRFRUC initialization needed: Changes to WRF SI (Brent Shaw) – use of native RUC vertical coordinate rather than isobaric levels to provide initial fields of atmospheric variables including hydrometeors (vapor, cloud, ice, rain, snow, graupel) The most recent official release of WRF SI includes all these changes

13 REAL changes for WRFRUC initialization : Changes to REAL (Dave Gill) accommodate for level structure in RUC soil domain pass through hydrometeor fields Further changes needed to pass through from SI to WRF model other land-surface related variables such as : 2 fields for snow temperature snow density water vapor mixing ratio at surface liquid volumetric soil moisture and others

14 WRFRUC LSM uses : -soil and vegetation parameters, vegetation fraction and albedo provided by WRF SI -cycled soil temperature and moisture from RUC20 (RUC and WRFRUC use the same LSM, land-use and soil classifications, and the same parameter tables) -cycled snow depth and temperature from RUC20 -ice in soil is initialized in WRF Atmospheric forcing is provided by WRF. Still need from WRF modeling framework: -precipitation type (solid versus liquid) -option in surface driver for implicit solution of energy and moisture budgets

15 Vegetation types – both provided by WRF SI (24 USGS classes) RUC20 WRF10 Land-use parameters: roughness length emissivity plant coefficient

16 RUC20 WRF10 Soil types – both provided by WRF SI (16 classes) Soil parameters – look-up table

17 Soil moisture analysis Valid 0000 UTC 17 June 2003 RUC20 WRF10

18 RUC10 Terrain Elevation (dm) TAQ domain RUC20

19 Surface temperature 0000 UTC, 17 June 2003 RUC20

20 Part 2: Evaluation of LSM performance

21 RUC LSM participated in:  Project for the Intercomparison of Land-Surface Parameterization Schemes (PILPS) - Phase 2d  Snow Models Intercomparison Project (SNOWMIP) – Phase 1 RUC LSM is implemented in: Operational RUC20 at NCEP Real-time RUC20 at FSL (CDAS) MM5 chemistry package (Georg Grell) used for - air quality predictions - regional climate simulations (FSL, Germany, Israel) WRF model

22 Improved 1-d (PILPS 2d – Valdai, Russia) total runoff and snow water equivalent forecasts with improved snow and soil physics in MAPS land- surface model Total runoff Snow water equivalent Skin temperature November May 1977

23 Effects of frozen soil physics on the simulation of the melting seasons, Valdai, Russia ( ) Dates when snow ablation starts Dates when snow pack is all melted (Smirnova et al., JGR (2000), 105, )

24 SNOWMIP, an intercomparison of snow models: first results P. Etchevers, E. Martin, R. Brown et al. ISSW meeting, August 2002

25 NESDIS daily snow cover 7 January January 2003 Cycled field of snow depth from operational RUC20 at NCEP Valid at 2100 UTC 8 January 2003

26 WRF RUC 12-h forecast Valid 1200 UTC 29 January 2003

27 WRF-10 RUC h forecast of surface temperature from RUC and WRF against RUC-20 analysis 1800 UTC 29 January 2003 RUC-20

28 Hartford, CT 9 June UTC – 11 June UTC Station verification for TAQ project

29 Boston, MA 9 June UTC – 11 June UTC Station verification for TAQ project

30 Worcester, MA 9 June UTC – 11 June UTC Station verification for TAQ project

31 VariableRUCWRFRUC Wind spd – s.d Wind spd bias Temp –s.d.2.7 Temp – bias-00z Dewpoint – s.d Dewpoint – bias h surface forecasts verified vs. METAR obs 11 April – 11 June 2003 RUC-20 vs. WRFRUC-20 – all METARs in domain

32 12-h winds aloft forecasts – verified against rawinsonde RUC-20 vs. WRFRUC-20

33 RUC-20 (Grell- Devenyi cumulus) WRFRUC-20 (KF cumulus) 21-h forecasts Valid 2100 UTC 10 June 2003