Add support for Stochastically Perturbed Parameterizations (SPP) in the FV3

[JeffBeck-NOAA]

Description

Add the necessary code in ufs-weather-model, fv3atm, ccpp-physics, and stochastic_physics to run the FV3 with Stochastically Perturbed Parameterizations (SPP). The associated code uses the stochastic_physics pattern generator (same as for SKEB, SHUM, and SPPT) to create a random pattern based on scales, magnitudes, etc., from the FV3 input.nml namelist and perturbs RAP/HRRR-based physics scheme parameters in selected parameterizations.

Namelist options:
&gfs_physics_nml
do_spp = .true. or .false. -- flag to turn SPP on/off; .false. is the default
n_var_spp = 1 -- determines the number of RAP/HRRR-based schemes that will be perturbed by SPP (these include MYNN SFC, MYNN PBL, RRTMG, GSL GWD, and Thompson MP)

&nam_sppperts (new stanza in namelist; all settings here are comma separated and apply to the parameterizations listed in 'spp_var_list')
iseed_spp = 4 -- the initial seed value for the perturbation pattern
spp_lscale = 150000.0 -- length scale in meters
spp_prt_list = 0.2 -- perturbation magnitude
spp_sigtop1 = 0.1 -- controls vertical tapering of perturbations at the tropopause
spp_sigtop2 = 0.025 -- controls vertical tapering of perturbations at the tropopause
spp_stddev_cutoff = 2.0 -- perturbation magnitude cutoff in number of standard deviations from the mean
spp_tau = 21600.0 -- time decorrelation length in seconds
spp_var_list = 'gwd' -- the list of parameterizations to perturb (options include 'pbl', 'sfc', 'rad', 'gwd', and 'mp')

Solution

Perturbs selected parameters in RAP/HRRR-based physics parameterizations, identically to how SPP was implemented in WRF (Jankov et al 2017 and Jankov et al 2019). Uses pre-existing SPP code in ccpp-physics from WRF-based parameterizations, but which was disabled during the transition to CCPP. Changes were only made where necessary to implement all parameter perturbations correctly within CCPP.

Related to

PR #982 and needed by companion PRs in stochastic_physics, ccpp-physics, and fv3atm.

@llpcarson, @jwolff-ncar, @willmayfield, @bluefinweiwei, @michelleharrold, @judithberner, @pjpegion

[junwang-noaa]

The code changes were committed, The issue is closed.