Physics Test Harness

Physics Testing Harness Hierarchy
Conceptual illustration of the simple-to-complex hierarchical structure of the physics test harness. Colors denote potential responsibility for carrying out each type of testing. Physics developers are expected to be involved throughout the process and conduct less computationally expensive testing on their own machines. DTC staff can support and carry out testing up to and including low and medium resolution (LR/MR) global forecasts with data assimilation. Operational centers are expected to contribute support and computational resources if complex testing is warranted.

The GMTB physics testing harness provides a common infrastructure for testing physics parameterization developments for potential applicability for NWP. It consists of several “tiers” of modeling configurations arranged in a simple-to-complex hierarchy. Testing a physical parameterization innovation within such a structure allows for the sequential addition of model feedbacks that add layers of complexity to the interpretation of results as testing proceeds toward an operational configuration. Priority development of the physics testing harness has been focused on the single column model and low/medium resolution global reforecast tiers (using cold starts and cycling with data assimilation).

Single Column Model (SCM)

  • Represents the simplest way to test a physics suite as an entity while eliminating bias from a dynamical core. An atmospheric column is “forced” by observed or modeled large-scale meteorological conditions within individual case studies.

  • Uses the current version of CCPP to connect to the current operational GFS physics.

  • Documentation for obtaining, running, and analyzing output from the GMTB SCM is available. Data to run one test cases is included and users are encouraged to develop and run new case studies.

Global Model Infrastructure

  • A model infrastructure that uses the NOAA/EMC pre-processing (using either cold start or cycled runs with data assimilation), experimental FV3-based GFS, and post-processing, combined with a Python graphics package, model verification using the DTC's MET software, and several diagnostic tools is available for interested collaborators.

  • Model Evaluation for Research Innovation Transition (MERIT): An end-to-end research and operational framework established to streamline the testing process in order to accelerate more effective and efficient physics development, encourage community engagement, and provide an infrastructure that supports R2O and O2R.

Utilities and Diagnostics

  • A number of process-oriented diagnostic tools that offer in-depth insight on strengths and weaknesses of physics parameterizations. 

Future Development

The tools within the physics test harness will undergo substantial changes to keep up with NOAA’s shift to the FV3 dycore and continued changes to physics. The effort required for introducing new physics schemes for testing will be considerably reduced as the modeling applications transition to using the Common Community Physics Package ecosystem.