The WRF Standard Initialization (WRFSI)

1. The WRF Standard Initialization (WRFSI) Brent Shaw NOAA / Forecast Systems Laboratory Presented by Paul Schultz June 27, 2002

2. WRF Standard Initialization • Provides a method to define a WRF domain • Location, projection, dimensions, resolution • Acquisition/interpolation of “static” fields • These functions are now available via a graphical user interface • Provides all required initial and time-varying boundary conditions required to produce a forecast on the native WRF coordinate • Ingest readily-available gridded fields (NCEP GriB) • Horizontally/vertically interpolate to WRF domain • Grid staggering to support dynamic core • Derivation of state variables required by dynamic core • The GUI will support these functions in a few months

3. WRF Standard Initialization • Role of FSL • Lead agency for SI Working Group (John McGinley) • Designed, developed, and delivered initial version of WRF SI system • Maintenance/enhancement of initial system • Reformatting static fields • Status • Running in real-time at NCAR, AFWA, FSL, ... • Test use at EMC • Released new version to NCAR in March • Supports mass-based vertical coordinate • Supports A-grid • Supports condensate fields and nonzero divergence for diabatic initialization • Additional fields to support LSM (frozen soil physics) • Refined interpolation methods for land/water “masked” fields

4. WRFSI Current Capabilities • Domain Definition • Choice of 3 projections • Polar stereographic • Mercator • Lambert Conformal (secant or tangent) • Arakawa-C Grid Stagger with no nesting • Static field processing from tiled data sets • Dynamic Data Pre-processing • GriB-format pressure-level and surface data sets • Horizontal Interpolation • From Lat/Lon, polar-stereo, Lambert conformal, or mercator • Vertical Interpolation • From pressure to pressure or WRF height/mass • From RUC native to pressure or WRF height/mass

5. WRFSI Software Design • Modular • Components can be run individually • New components can be easily inserted into run stream • New options can be more easily added • Single namelist file for control • Maintainable • CVS Revision control • Multiple platform build and testing strategy • Design emphasis on portability • Accommodations for Graphical User Interface

6. topo Grib data (AVN, Eta, RUC) WRF-ready init/lbc land use others WRFSI Software Components Define Domain Populate the Domain Reformat Data

7. Program grib_prep • Reads and re-formats GRIB-format data files containing pressure-level data. Does no spatial interpolation. • Runs whenever new input data sets available. Output from one run can support multiple model runs on various domains. • User-editable configuration table allows use of any level(s) of any variable contained in the GRIB file • Provides time-interpolation to fill gaps in data to meet desired LBC frequency • Writes simple, intermediate file for input to hinterp, • Simple file format allows users to bypass grib_prep if they have custom, non-GRIB datasets

8. Program gridgen_model • Run once when domain initially defined • Acquires/derives all required static fields • Topography with user-controllable filtering parameters • Latitudes, longitudes, map factors, coriolis, etc. on model stagger (Arakawa C). Also A-grid for 3DAVR. • All required fields for LSM support • USGS 24-category landuse fractions • WMO/FAO 16-category 2-layer soil types • Annual mean temperature, monthly greenness fraction, albedo • Reads “tiled” data sets (available on FTP server) • Outputs netCDF file

9. Program hinterp • Runs once per domain per model run • Reads static file and grib_prep output • Horizontally interpolates pressure level data to the WRF horizontal staggered (Arakawa-C) domain • Utilizes special routines for interpolation of masked fields (e.g., soil moisture, soil temperature, SST, snowcover, etc.) • Selectable interpolation method • Processes any variable contained in grib_prep output • Outputs binary-format data and metadata

10. Program vinterp • Run once per domain per simulation • Vertically interpolates pressure levels to WRF coordinate • Linear interpolation of height w.r.t. ln(p) • Linear interpolation of other variables w.r.t. height • Derives variables needed for input to Runge-Kutta dynamic engine • Processes all variables found in hinterp output • “Pass-through” of scalars, 1D, and 2D variables • Vertical interpolation of 3D variables • Performs final staggering of atmospheric variables • Outputs binary files for input into the WRF "real.exe" initialization program

11. Perl Scripts • install_wrfsi.pl: Builds the software • wrfsi.pl: Main driver script for running • grib_prep.pl: Runs grib_prep.exe • interp.pl: Runs gridgen_models (optional), hinterp.exe, and vinterp.exe • window_domain_rt.pl (in forthcoming release): Sets up domain from pre-existing namelist template • localize_domain.pl: Edits namelists and cdl file and runs gridgen_model.exe • The GUI is intended to make all this a breeze -- maybe late summer.

12. Miscellaneous Utilities • IDL Routines • read_wrf_static.pro: Reads WRFSI static file • read_gribprep_output.pro: Read grib_prep output files • get_wrf_variable.pro: Reads hinterp/vinterp output • Program siscan (in forthcoming release) • Dumps a summary of wrfsi file contents

13. WRFSI Setup Overview • Ensure required external packages are installed • Plan the directory setup • Extract the tar file • Configure compiler options • Run the installation script • Configure the domain • Run the main driver script as necessary

14. GUI demo We’re going to do this instead of going over all the details of software installation, which you can read for yourself by downloading this presentation. Also, there’s a presentation later today on SI software installation.

15. Required External Packages • Unix or Linux OS • Fortran 90 Compiler • C Compiler (gcc is sufficient) • make Utility • Perl • netCDF Libraries

16. WRFSI Setup • Directory structure and environment variables • "Source root" ($SRCROOT) -- Approx. 10 MB • Typically this is the top-level directory created after extracting the tar file • Contains src, etc, and data subdirectories • "Installation root" ($INSTALLROOT) -- Approx. 10 MB • Where installed code will reside • Contains bin and etc subdirectories • "MOAD data root" ($MOAD_DATAROOT) • Where data specific to a single domain resides • Contains static, siprd, cdl, and silog subdirectories • "External data root" ($EXTDATAROOT) • Location of grib_prep output • Contains extprd, work, and log subdirectories

17. WRFSI Setup • Directory Structure Rationale • Allows separation of executables and source code • Provides a smooth upgrade path in an operational environment • Easier to test modifications without impacting operations • Allows separation of transitory data from source code and executable code for improved management of disk volumes • Allows modular programs to communicate effectively • Very flexible • $INSTALLROOT, $SRCROOT, and $MOAD_DATAROOT can all be the same or different • Supports multiple domains ($MOAD_DATAROOTs) with one set of executable code ($INSTALLROOT) and external data ($EXTDATAROOT)

18. WRFSI Setup • Compiling • Uses Unix or Gnu make utility • Machine-dependent settings in one shared file ($SRCROOT/src/include/makefile.inc) • Top-level makefile ($SRCROOT/Makefile) can compile and install everthing, or each component can be individually compiled • Perl script "install_wrfsi.pl" handles editing of makefile.inc file, compilation, and installation based on command-line options • Requires $SRCROOT/src/include/makefile_{machine}.inc.in to be present with correct compiler options, etc.

19. WRFSI Setup • Configuring the domain (current method) • Edit $MOAD_DATAROOT/static/wrfsi.nl • Horizontal parameters (projection, grid spacing, dimensions) • Vertical level distribution • Paths to GRIB data • Path to $EXTDATAROOT • Edit dimensions in $MOAD_DATAROOT/cdl/wrfsi.cdl • Run gridgen_model.exe manually or allow it to be run on the first execution of wrfsi.pl • Configuring the domain (forthcoming) • Edit a template file for the domain • Run $INSTALLROOT/etc/window_domain_rt.pl

20. Running WRFSI • Execute $INSTALLROOT/etc/wrfsi.pl • Set $MOAD_DATAROOT and $INSTALLROOT environment variables or provide to wrfsi.pl as command line options • Examples: • wrfsi.pl 2001081612 24 ETA testdomain • wrfsi.pl -i /my/install/root -d /my/data/root 2001081612 24 ETA testdomain • Output will be in $MOAD_DATAROOT/data/siprd • Example output files: • wrf_input.global.metadata • wrf_input.d1.2001-08-16-12:00:00 • wrf_input.d1.2001-08-16-15:00:00 • ... • wrf_input.d1.2001-08-17-12:00:00

21. Sample SI Output USGS Landuse on 10-km National Domain Soil Moisture on 16-km Domain Pot. Temp on 16-km Domain Water Vapor on 16-km Domain

22. WRFSI Software Management • CVS revision control • Weekly, multi-platform builds performed at FSL • IBM AIX, Intel-Linux, Alpha-Linux • Latest version and static data available on FSL anonymous FTP server • ftp://ftp.fsl.noaa.gov/pub/frd-laps • WRFSI.TAR.gz • *TILES.tar.gz • TERRAIN_GLOBAL_30s.tar • Bug reports, comments, etc. are encouraged!

23. Plans(as resources allow) • Support for nested grids • Graphical User Interface • Support grib_prep, hinterp, vinterp • Accommodate other initializations (3DVAR, LAPS, etc.) • Schedule/manage model runs • Parallelization (?) • Maintenance and general software improvements