The SPP implementation in IAL and HARMONIE

The Stochastically Perturbed Parameterizations scheme (SPP) introduces stochastic perturbations to values of chosen closure parameters representing efficiencies or rates of change in parameterized atmospheric (sub)processes. See here for more information. See the main SPP documentation for selection of settings.

Controling routines

The SPP data structure and logics is controlled by the following routines

Routine	Description
`src/arpifs/module/spp_mod.F90`	Defines SPP scheme types `TSPP_CONFIG_PAR` and `TSPP_CONFIG` for the parameter config and the overall config respectively
`src/arpifs/module/spp_mod_type.F90`	Harmonie specific data types `TSPP_CONFIG_TYPE`, `ATM_SPP_VARS`, `SFX_VARS`, control and the methods `CLEAR_SSP_TYPE`, `SET_SPP_TYPE`, `APPLY_SPP`, `APPLY_SPP_SURFEX`, `DIA_SPP`, `SET_ALL_ATM_SPP`, `SET_ALL_SFX_SPP`, `CLEAR_ALL_ATM_SPP`, `CLEAR_ALL_SFX_SPP`
`src/surfex/SURFEX/modd_sfx_spp.F90`	SURFEX specific data types, control and methods `CLEAR_SFX_SPP`, `SET_SFX_SPP`, `APPLY_SFX_SPP`, `CLEAR_ALL_SFX_SPP`, `SPP_MASK`, `SPP_DEMASK`, `PREP_SPP_SFX`. Partly duplicates spp_mod_type.F90
`src/arpifs/namelist/namspp.nam.h`	The SPP namelist
`src/arpifs/setup/get_spp_conf.F90`	Setup defaults and read the SPP namelist. Initialises the SPG parameters
`src/arpifs/phys_dmn/ini_spp.F90`	Initialises the pattern used for SPP
`src/arpifs/phys_dmn/evolve_spp.F90`	Control routine for pattern propagation
`src/mse/internals/aroset_spp.F90`	Initialises the SURFEX part of SPP

Note that the control routines shared with IFS will be totally rewritten, and much neater, with the introduction of CY49T1. See e.g. spp_def_mod.F90, spp_gen_mod.F90

SPG routines

The pattern used for SPP within HARMONIE is SPG and the code for this is found under src/utilities/spg. For the propagation of the pattern we find the routine EVOLVE_ARP_SPG in src/arp/module/spectral_arp_mod.F90

Applying the patterns

In apl_arome.F90 the HARMONIE specific data types are initialised with SET_ALL_ATM_SPP and SET_ALL_SFX_SPP. These routine groups the different parameters and connects them to a pattern and a the correct diagnostic field EZDIAG if requested.

Applying the patterns in the upper air part

In the routine were a specific parameter is used the pattern is applied by calling APPLY_SPP. This is done for each parameter accoding to the table below.

Perturbation	Routine
`RADGR`	`src/arpifs/phys_dmn/apl_arome.F90`
`RADSN`	`src/arpifs/phys_dmn/apl_arome.F90`
`RFAC_TWOC`	`src/arpifs/phys_dmn/vdfexcuhl.F90`
`RZC_H`	`src/arpifs/phys_dmn/vdfexcuhl.F90`
`RZL_INF`	`src/arpifs/phys_dmn/vdfexcuhl.F90`
`RZMFDRY`	`src/arpifs/phys_dmn/vdfhghtnhl.F90`
`RZMBCLOSURE`	`src/arpifs/phys_dmn/vdfhghtnhl.F90`
`CLDDPTHDP`	`src/arpifs/phys_dmn/vdfhghtnhl.F90`
`RLWINHF`	`src/arpifs/phys_radi/recmwf.F90`
`RSWINHF`	`src/arpifs/phys_radi/recmwf.F90`
`PSIGQSAT`	`src/mpa/micro/internals/condensation.F90`
`ICE_CLD_WGT`	`src/mpa/micro/internals/condensation.F90`
`ICENU`	`src/mpa/micro/internals/rain_ice_old.F90`
`KGN_ACON`	`src/mpa/micro/internals/rain_ice_old.F90`
`KGN_SBGR`	`src/mpa/micro/internals/rain_ice_old.F90`
`ALPHA`	`src/mpa/micro/internals/rain_ice_old.F90`
`RZNUC`	`src/mpa/micro/internals/rain_ice_old.F90`

Applying the patterns in SURFEX

As SURFEX should have no dependencies to external modules the data is copied into the internalt SURFEX SPP data structure in AROSET_SPP called from ARO_GROUND_PARAM.

For SURFEX the parameter table looks like

Perturbation	Routine
`CV`	`src/surfex/SURFEX/coupling_isban.F90`
`LAI`	`src/surfex/SURFEX/coupling_isban.F90`
`RSMIN`	`src/surfex/SURFEX/coupling_isban.F90`
`CD_COEFF`	`src/surfex/SURFEX/surface_cd.F90`
`CH_COEFF`	`src/surfex/SURFEX/surface_aero_cond.F90`

In SURFEX we also have to pack/unpack the data arrays to only use the active points for a specific tile or patch. This is done in the SPP_MASK and SPP_DEMASK routines found in src/surfex/SURFEX/modd_sfx_spp.F90 and called from src/surfex/SURFEX/coupling_surf_atmn.F90. At the time of writing returning the diagnostics of the pattern doesn't work satisfactory.

The additional code changes done for SPP in SURFEX can be viewed here