Nudging and Surface coupling issues for recent nudging simulations

[AaronDonahue]

There are a number of issues that come up when running a CIME based case w/ nudging turned on. This issue lists them so we can track progress on addressing them.

Nudging:

• [x] Typical output only provides horiz_winds as an option instead of u and v which is what is needed in nudging.
• [ ] Nudging source data may include masked values, which we do not want to include when interpolating data onto the simulation state. Could lead to strange nudging values.
• [x] Re: basic usage of nudging - nudging by itself not recognized for requesting tendencies as output, must use compute_tendencies=all
• [x] Re: basic usage of nudging - Cannot use atmchange to specify nudging params.
• [x] Nudging currently assumes all data is in only one file - expect to use multiple files for production runs.
• [x] Nudging expects P_levs (3D) but it should allow it to be a static field (1D)
  • [ ] Update coarsened output to write out 1D staticP_levs

Surface Export Replacement:

• [x] Not a big issue, but the names of surface export variables do not match the output names for a typical run, requiring a processing step on source data to change variable names.

[AaronDonahue]

I'm making this issue to track all the little things we want to take care of with PR #2378