WRF “Lite”: Streamlining the WRF Model

Carlie Coats and John McHenry
Baron AMS


We envision a WRF "Lite" modeling system that uses the "Science Module" code from the main WRF repository, but that is embedded in a much more friendly framework and build system. The framework would take advantage of the extensive higher level facilities found in the Models-3 I/O API (M3IO), and would have much friendlier and simpler driver and solver codes. At the same time, it should have greater efficiency both for the parallel communication and for the implementation of dynamics in the solver. We envision the development as having two phases: first, hand coding the "Pilot Project" model (complete with make system) implementing the NCEP model configuration and using it to test various optimizations; then building a "Community" model configuration system that constructs the driver and solver code and make system (patterned after the code for the Pilot Project model) for a model that satisfies a user's model-configuration specification.

We believe that in Phase 1, by combining the expertise of the staffs at NCEP, BAMS, and NOAA/ASMD, we can construct a version of WRF that is at the same time much friendlier and much more efficient than the current NCAR versions. In the Phase 2 follow-on perhaps we would use additional assistance in "code-writing" languages like python to construct a model configuration and build system much friendlier and at the same time more flexible and robust than NCAR's Registry/compile.

At the same time, we believe that both NCEP and BAMS have considerable expertise at improving the performance of various critical science modules. (The BAMS version of Reisner-1 microphysics is about five times faster than its NCAR predecessor, for example, using optimization ideas not to be found in any current WRF microphysics routine.) As an independent effort, we suggest collaboration for developing selected new science modules using our combined expertise.