bug: ROMS rutgers assuming state QTY_SEA_SURFACE_HEIGHT for model_interpolate but user may not have supplied it

[hkershaw-brown]

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Describe the bug

1. Run ROMS_rutergers pmo, only interested in u,v current observations so only add u,v current to the state
2. Successful run of pmo
3. dart throws this error:

 PE 0: perfect_model_obs: Ready to evaluate up to    1552 observations
 ERROR FROM:
  routine: get_dart_vector_index
  message:  Can not calculate indices for variable  ndims =            0
 
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI COMM 3 DUP FROM 0
  Proc: [[18877,0],0]
  Errorcode: 99

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.

Which model(s) are you working with?

ROMS_rutgers

Version of DART

v11.19.0

Have you modified the DART code?

No

Build information

This was reported on an ubuntu linux machine, unknown gfortran version, reproduced on my mac:
Mac M
GNU Fortran (MacPorts gcc13 13.3.0_2+stdlib_flag) 13.3.0
will affect any machine/compiler

Notes

It is this code, sshid is negative (not in state)so get_dart_vector_index barfs.

DART/models/ROMS_rutgers/model_mod.f90

Lines 401 to 408 in a32ab03

	! We always need to get the value of SSH at the 4 corners
	! because we need to compute the depth using it.
	! Recall that SSH can be both -ve and +ve
	sshid = get_varid_from_kind(domid, QTY_SEA_SURFACE_HEIGHT)
	do i = 1, Nc
	dartidx = get_dart_vector_index(lon_c(i), lat_c(i), 1, domid, sshid)
	SSHcorn(i, :) = get_state(dartidx, state_handle)
	enddo

Assuming ssh is there, maybe just return with error telling you to add 'zeta', 'QTY_SEA_SURFACE_HEIGHT' to the state.

[mgharamti]

SSH is such a central variable for this interface, particularly for interpolation when computing depth. It has to be part of the state. I agree, we should fail right away if the state doesn't have SSH.