[MITgcm-support] Nonlinear free surface and the adjoint

[Christopher L. P. Wolfe]

Hi all,

I’m trying to do sensitivity studies using a nonlinear free surface. TAF gives warnings about extensive recomputations that disappear when I turn off the NLFS using #undef NONLIN_FRSURF in CPP_OPTIONS. I’ve heard that ECCOv4 uses the NLFS in both forward and adjoint mode, so either the recomputations are not that bad or there’s a way to make them go away. Does anyone know which is the case?

If neither, is there a flag I could set to use the NLFS for the forward integration but have it turned off in the adjoint?

Thanks,
Christopher