P53 Evaluation of an advanced convective scheme using the Global Model Test Bed's physics test harness

Firl, Grant, Michelle Harrold, National Center for Atmospheric Research and Developmental Testbed Center (NCAR/DTC), Man Zhang, Cooperative Institute for Research in the Atmosphere, affiliated with NOAA/ESRL/GSD and DTC (NOAA/DTC), Jamie Wolff, NCAR/DTC, Judy Henderson and Ligia Bernardet NOAA/DTC, and Joshua Hacker, NCAR/DTC

The Developmental Testbed Center has developed a new physics test harness as part of the Global Model Test Bed (GMTB). It consists of a single column model (SCM) and a workflow for running the GSM with postprocessing, verification, and diagnostics. The goal for the testbed is to be able to objectively compare advanced physics suites with physics from operational centers and other physics that are part of a Common Community Physics Package (CCPP). As an exercise for the testbed, the operational GFS physics suite using SAS deep convection was modified to use the Grell-Freitas deep convective scheme. The SCM was run using initial conditions and forcing derived from a maritime deep convective case based on the TWP-ICE field campaign. A comparison of the physical tendencies produced by the individual schemes and other diagnostics from the SCM provided an economical way to shed light on results produced by more expensive, global runs. The global workflow was used to run the GFS as done operationally (except with reduced horizontal resolution due to computational constraints) for the control and modified physics. While one must be careful extrapolating the results from a simplified global workflow, such tests provide meaningful guidance about physics advancements.