[MITgcm-devel] cost function terms for obcs

[Martin Losch]

Hi Patrick, Matt and who-ever is affected,

I'd like the reformulate the obcs cost terms. Currently the some mean velocity, e.g., ubar (which is a monthly mean, as far as I can see) is compared to the prescribed u-component field at the open boundary, say OBNu. While this is perfectly valid, it makes more sense to me (and is more general) to constrain the deviation from the first guess (OBNu), that is, to use the control variable stored in xx_obcsn.*.data directly, ie., sum up all xx_obcsn^2. This way, the contribution from the open boundaries is zero at iteration zero.

Patrick, you have already pointed me to how to do this, but I did not get to it immediately. Could you please remind me, where I can see examples of how to read these files? Was it cost_forcing_gen.F?

The other question is whether this is a formulation useful to others (I think so) and if so how should I include into the repository? As additional files, or CPP-flags in cost_obcs?.F? Or even replace the old formulation?

Martin