Stochastic physics in MPAS stand-alone #204
Description
Over the past year, our DTC team (@JeffBeck-NOAA, @NingWang325, @gsketefian, @willmayfield, @CPKalb) has been working to implement UFS-based stochastic physics, into MPAS stand-alone. We now have the capability to generate and integrate a single stochastic physics perturbation pattern on an MPAS mesh, followed by application of SPPT. In the next few weeks, we plan to open a PR to this repository to add this functionality. A companion PR for NOAA-PSL/stochastic_physics will be opened in parallel, with an associated repo issue here.
Latitude/longitude points from the MPAS mesh are passed into the NOAA-PSL/stochastic_physics code, from which the perturbation pattern is generated. This pattern is then passed back into the MPAS-Model code and used to introduce perturbations to the total tendencies produced by the physics. Testing has indicated that SPPT is working as expected and produces reasonable results, but computational cost is a concern we are hoping to address in the near future. A plan to move away from global spherical harmonics for the generation of a regional perturbation pattern toward a double Fourier method (used for stochastic physics in WRF) is being evaluated.
Further development will focus on allowing multiple perturbation patterns, while also adding SKEB, SHUM, and eventually SPP. Collaboration with Judith Berner (NCAR/MMM) and I-Han Chen (Meteorological Service Singapore) has resulted in preliminary SPP functionality.
Friendly testers are welcome to evaluate this code and provide feedback.