Good afternoon, everyone!

I'm running a coupled OpenIFS 43r3 + NEMO ORCA05 model with a runoff mapper similar to that of EC-Earth.
The runoff mapper collects surface and sub-surface runoff from HTESSEL and eventually sends this as runoff to NEMO.

However, I noticed that the "runoff" in NEMO (actually calving) coming from Antarctica was zero during the austral winter.
This leads me to the question: How is runoff actually computed over Antarctica?

I did a 1 year simulation and plotted total E+ES+TP (precipitation minus evaporation) and RNF (surface runoff + subsurface runoff). The numbers are roughly mm/year.
The output has been interpolated from the reduced O96 grid to a regular grid so the numbers are not exactly what OpenIFS uses internally.
I find plenty of net downward freshwater fluxes over Antarctica (over 100 mm/year) that does not correspond to any runoff.
This only makes sense if freshwater is advected central Antarctica towards the ocean by HTESSEL.

Is the water flux over this region transported towards the ocean by HTESSEL, and then accumulated in the runoff field?
Or does HTESSEL ignore snowfall over this region, i.e. the freshwater budget is not closed?

Many thanks
Joakim