Salt flux terms in MOM6

COSIMA
1

I’m look at surface fluxes in the PanAntarctic model (MOM6). My meltwater experiment uses prescribed restoring via a salt correction (online restoring turned off). It seems that salt_flux_addedincludes both online restoring and salt correction, whilst salt_flux is described as net flux (restoring + sea-ice).

So for total surface salt flux for the meltwater experiment, I have salt_flux + salt_flux_added. For total surface salt flux for the control, I have salt_flux (but not adding salt_flux_added?). When including salt_flux_added in the control surface forcing, the plots look potentially more reasonable. So now I am a bit confused on whether the salt correction is also included in salt_flux, and just in general exactly what terms are included in each variable? Any help is much appreciated!

3

Hi Katja

I had a quick look in ACCESS-OM3 and didn’t discover anything - I also would have thought salt_flux included all salt fluxes (e.g. the online restoring, and the correction and sea ice etc) - ref

@dougiesquire is on leave this morning but will have a more comprehensive look this afternoon

4

I think this could be incorrect in the PanAntarctic – Dougie recently fixed this in the ACCESS-NRI fork of MOM6 Add salt flux adjustment (sflx_adj) to `fluxes%salt_flux` by dougiesquire · Pull Request #18 · ACCESS-NRI/MOM6 · GitHub , but this is predated by panan.

And just on re-reading your post:

It seems that salt_flux_addedincludes both online restoring and salt correction, whilst salt_flux is described as net flux (restoring + sea-ice).

Yes, salt_flux_added should include the restoring and sflx_adj adjustment. salt_fluxshould include restoring, sea ice, and the adjustment.

5

Okay great, thank you! The PanAntartic experiment I’m using had incorporated Dougie’s fix, so it looks like the adjustment will be in salt_flux for this experiment. Thanks!