GF Testing


This test was conducted by the Global Model Test Bed (GMTB) to inform the development of an advanced physics suite for NOAA's Global Forecast System (GFS). It is a state-of-the-art scheme that has been developed recently, but follows a long line of parameterizations from the developers. It includes a scale-aware feature, which make the scheme suitable for use in a wide range of model resolutions. Additionally, it incorporates an ensemble approach to the representation of convection, which can improve the forecast by using a collection of parameters and algorithms to represent the convective triggers, vertical mass flux, and closures. The ensembles can also be perturbed by stochastic fields for deterministic forecasting as well as ensemble data assimilation. Flux form tracer transport, wet scavenging, and aerosol awareness are also options in this scheme.

The test was conducted using GMTB's hierarchical testbed, comprised of both a Single Column Model (SCM) and a workflow to run the GFS. Given that this was the first test conducted by GMTB, a relatively new group within the Developmental Testbed Center (DTC), this test also served to vet various aspects of the hierarchical testbed, and as an exercise to get the testbed in place and ready for future physics assessments.

The GMTB staff would like to thank the GF developer (Georg Grell of NOAA/ESRL), the NOAA/EMC Global Team led by Vijay Tallapragada, the NGGPS Physics Team co-leads (then Jim Doyle of NRL, Shrinivas Moorthi of NOAA/EMC and Bill Kuo of NCAR), and the NGGPS Program Office led by Fred Toepfer for their engagement in preparing the test plan, defining verification metrics, supplying code, and participating in the interpretation of results.