Foreword
This User’s Guide describes the Advanced Research WRF (ARW) Version 4.4 modeling system, released in April 2022. As the WRF/ARW is developed further, this document will be continuously enhanced and updated. Please post feedback to the WRF & MPAS-A Support Forum.
This document is complementary to the ARW Tech Note (https://opensky.ucar.edu/islandora/object/opensky:2898), which describes the equations, numerics, boundary conditions, and nesting etc. in greater detail.
Highlights of updates to WRFV4.4 include:
· WRF model:
Physics:
o Added a shallow water roughness scheme (contributed by P. Hawbecker of NCAR).
o Added stochastic ensemble prediction capability to WRF-Solar physics suite (contributed by P. Jimenez, J. H. Kim of NCAR, and J. Yang of NREL).
o Changed climatological greenhouse gas concentrations from compile-time option to run-time option for RRTM, RRTMG, CAM and Dudhia options. The default uses CAMtr_volume_mixing_ratio.SSP245.
o Updated input to Thompson aerosol-aware scheme: added black carbon in climatology, added support for real-time water/ice friendly and black carbon, as well as biomass burning aerosol. Near-surface aerosols can be added to the model via qna_update option and wrfqnainput_d0* (contributed by T. Juliano of NCAR).
o Several updates for NoahMP LSM scheme that include 1) a few runoff schemes, 2) new drainage capability, 3) soil time step control, and 4) more diagnostic output (contributed by LSM group of NCAR).
o A capability to obtain NoahMP code from its own Github repository.
o Added capability to couple with CMAQ (contributed by J. Wong of EPA).
· WPS:
o Black carbon is added to the climatological aerosol data (T. Juliano of NCAR).
o Bathymetry data to use with shallow water drag option in WRF (P. Hawbecker of NCAR).
o Drainage data (US only) for NoahMP are added (Valayamkunnath of NCAR)
· WRF-DA updates:
o New capability to assimilate GPM GMI radiance data (D. Xu of Nanjing University of Information and Technology, China).
o New option for surface aerosol data assimilation with MADE-VBS aerosol scheme (S. Ha of NCAR).
o Option to ingest NCEP’s satwnd.bufr data to assimilate more AMVs that are not included in NCEP prepbufr file.
· WRF-Chemistry
o Accounted for subgrid boundary layer clouds from MYNN PBL in photolysis.
For the latest version of this document, please visit the ARW Users’ Web site at http://www2.mmm.ucar.edu/wrf/users/.
Contributors to this guide:
Wei Wang, Cindy Bruyère, Michael Duda, Jimy Dudhia, Dave Gill, Michael Kavulich, Kelly Werner, Ming Chen, Hui-Chuan Lin, John Michalakes, Syed Rizvi, Xin Zhang, Judith Berner, Domingo Munoz-Esparza, Brian Reen, Soyoung Ha and Kate Fossell
Contributors to WRF-Fire chapter:
Jonathan D. Beezley, Janice L. Coen, and Jan Mandel
Special Acknowledgment:
We gratefully acknowledge the late Dr. Thomas T. Warner for his years of research, development, instruction, leadership, and motivation in the field of NWP modeling.