Bug in the implementation of NEMO equation of state

[nikizadehgfdl]

Bob pointed out that subroutine calculate_compress_nemo in MOM_EOS_NEMO.F90 calls gsw_rho_first_derivatives which calculates the derivative of rho wrt pressure, but using the TEOS-10 equation of state. This should be using the NEMO equation of state instead.

[nikizadehgfdl]

@StephenGriffies NEMO provides partial derivatives of density wrt T&S. But to calculate the compressibility we need the partial derivative wrt pressure which NEMO does not provide. Hence we are using the TEOS10 provided function as an approximation

I will try to derive an expression using NEMO if they do not have one ready for use.

[StephenGriffies]

What is the status of this issue?

[StephenGriffies]

@nikizadehgfdl any update on this issue?

[Hallberg-NOAA]

This issue was addressed via https://github.com/NOAA-GFDL/MOM6/pull/331, which was merged onto the main branch of MOM6 on July 31, 2023.