Runoff redistribution

[aekiss]

Splitting off from #208 (comment):

1. do we need river runoff redistribution horizontally or vertically (rivermix)?
2. what's done if the JRA55do runoff is located on land on the model grid - is it teleported to the nearest wet cell?
3. do the area-integrated friver and ficeberg MOM6 diagnostics match the area-integrated fluxes in the RYF.friver.1990_1991.nc and RYF.licalvf.1990_1991.nc JRA55do source files? (may require different remapping and time interpolation - see River and iceberg runoff mapped to incorrect locations #208 (comment))

[aekiss]

Related: ACCESS-NRI/dev_coupling#32

[anton-seaice]

@kieranricardo reports you can't use the vertical mixing (RIVERMIX) with USE_REGRIDDING=True (which I think is important / fundamental)

[aekiss]

Thanks, if that's the case, we can't use RIVERMIX

[aekiss]

GFDL OM5 doesn't use rivermix

[aekiss]

ACCESS-OM2 used YATM to do online horizontal redistribution of runoff (sec 3.5.5. in the tech report).

I'm not sure what was done in ACCESS-CM2 but I gather it used a pre-calculated redistribution, perhaps created with https://github.com/COSIMA/runoff_tools

[access-hive-bot]

This issue has been mentioned on ACCESS Hive Community Forum. There might be relevant details there:

https://forum.access-hive.org.au/t/cosima-twg-meeting-minutes-2024/1734/22

[MartinDix]

CM2 MOM namelist had

&ocean_rivermix_nml
    debug_this_module = .false.
    river_diffuse_salt = .false.
    river_diffuse_temp = .false.
    river_diffusion_thickness = 0.0
    river_diffusivity = 0.0
    river_insertion_thickness = 40.0
    use_this_module = .true.
/

&ocean_riverspread_nml
    use_this_module = .true.
/

but model output has

 &OCEAN_RIVERSPREAD_NML
 USE_THIS_MODULE = T,
 DEBUG_THIS_MODULE       = F,
 RIVERSPREAD_DIFFUSION   = F,
 RIVERSPREAD_DIFFUSION_PASSES    =           0,
 VEL_MICOM_SMOOTH        =  0.200000000000000
 /

so I don't think the spreading is doing anything.

[ofa001]

Hi @MartinDix Yes I think I noted that earlier, as the parameters internally defaulted to zero.