WRF-NMM Users Page

WRF Modeling System Updates

The WRF model tar file has been updated to Version 2.2 on December 22, 2006.

The WRF V2.2 is backward compatible with SI and v2.1 real. One must add two new namelist records (&fdda and &grib2) to your namelist.input file from previous releases (see namelist.input files in test/nmm_real/ directory for an example).

Note: wrfinput_d01 and wrfbdy_d01 from V2.2 and cannot be used in previous releases of WRF.

WRF Version 2.2 new features, updates and bug fixes

WRF-NMM specific updates

  • Horizontal diffusion was made greater than zero at water points adjacent to steeply sloping coasts.

General updates

Phyiscs:

  • Microphysics
    • Ferrier
      • Updated parameters to be consistent with the operational NAM implementation in June 2006.
      • Modified code to improve interaction with ARW radiation options (cloud effect).
    • Thompson scheme
      • Revised scheme from the one in v2.1.
      • Preliminary testing for the NMM core was conducted.
    • WSM3, WSM5, WSM6
      • Improvement on ice and graupel physics. Snowfall diagnostics enabled.
      • A performance improvement was made for WSM5 which will change the results within round off.
      • Preliminary testing for the NMM core was conducted for WSM5 and WSM6.
  • Surface Layer Physics
    • MYJ
      • Roughness length refinements and various updates for consistency with operational NAM implementation in June 2006.
  • Land Surface Physics
    • RUC LSM
      • May use more than 6 soil layers.
      • Improved initialization from NAM data.
      • Preliminary testing for the NMM core was conducted.
    • LANDUSE.TBL: Some changes to albedo values for the winter season.
  • Planetary Boundary Layer
    • MYJ
      • Mass-weighting used in the vertical exchange and other updates for consistency with operational NAM implementation in June 2006.
  • Cumulus Schemes
    • BMJ
      • Updated code to be consistent with the operational NAM implementation in June 2006, including several bug fixes.
    • Grell-Devenyi scheme
      • Significant updates leading to improved results over water and over night. Improved interaction with GFDL radiation option.
      • Preliminary testing for the NMM core was conducted.
  • Atmospheric Radiation
    • Dudhia SW
      • Added a runtime (namelist) parameter, sward_scat, for tuning clear-sky shortwave scattering.
      • Preliminary testing for the NMM core was conducted.
    • GFDL
      • Updated code to be consistent with the operation NAM implementation in June 2006.
      • Changed optical properties of ice to include the sum of cloud ice and snow.
      • Saved convective cloud base and top values used by radiation.
      • Different saturation vapor pressure calculations are used when running Ferrier versus other microphysics packages.

Software:

  • New Features:
    • ESMF componenet support (experimental, currently works with ESMF 2.2.0rpl). Added a new test case called test/em_esmf_esp.
    • ESMF clock utility modified to allow backward integration.
    • Infrastructure streamlining: reduced reliance on Registry for generating actual and dummy argument lists used in mediation layer.
    • Added registry "include" and "ifdef" keywords. Shared registry file declaration combined to a single file: registry.io_boilerplate.
    • g95 support on Linux i486, i586, i686.
    • Grib 1 and 2 for input and output. Do not use gribmap.txt if the option is not used (contributed by Todd Hutchinson of WSI).
    • Increase number of input and history streams from 5 to 9 each.
    • Improved debug prints to contain domain and time information.
    • Port to IBM Blue Gene (experimental).
    • Parallel netcdf (Argonne Lab) I/O (experimental). Parallel netcdf library must be installed separately. See http://www-unix.mcs.anl.gov/parallel-netcdf/.
    • New time variable, XTIME, made available.
  • Fixes:
    • RSL_LITE: Bug fix for double-precision (64-bit) in MPI runs.
    • RSL: Bug fix.
    • ESMF time function can be compiled with lower versions of PGI compilers.
    • Netcdf I/O: add new metadata for mapping in GIS.
    • Remove unnecessary dimension 'ext_scalar' in netcdf I/O. WRF v2.2 will read netcdf data with or without this dimension, but will only write data without it. A patch is available to assist users who might want to use old WRF with new data.
    • Runtime option to write output files without colons.
    • Support metadata puts of logicals through quilting.