Add ability to convert exo to MPAS mesh when using MOLHO for optimization

[trhille]

Treat MALI layers as repeated instances of the Albany layer when necessary, so that we can convert an exodus file to a MALI .nc file when using the single-layer MOLHO solver for the optimization.

[trhille]

Testing

I tested this on MOLHO inversion output on a 4–40km Greenland Ice Sheet mesh. The MALI mesh has ten vertical layers, but the Albany mesh has a single layer.
mu:

Results at nVertLevel = 0:

Results at nVertLevel = 9:

[mperego]

@trhille thans for working on this. It is a good initial step and I'm OK if you want to merge this.
However, considering the MOLHO temperature uniform in the vertical coordinate is a crude approximation. The MOLHO temperature has two levels, T_bed and T_top, and you can interpolate the temperature in the interior according to:
T(sigma) = T_bed + (1-sigma^4) (T_top - T_bed)
where sigma is the sigma-coordinate. sigma is 0 at the top surface and 1 at the bed.
You can use same relation for the velocity.

[trhille]

However, considering the MOLHO temperature uniform in the vertical coordinate is a crude approximation.

Thanks @mperego! Glad I asked you to review :)

[trhille]

Testing (revisited)

After implementing the non-uniform depth profile for temperature and velocity, the results look better:
nVertInterface and nVertLevel = 0:

nVertInterface = 10, nVertLevel=9

[trhille]

Testing the more accurate enthalpy-based calculation for the temperature profile yields results that look correct. The added check confirms correct calculation:

  Verification: max |T_from_enthalpy - T_exo| at top = 0.000000e+00 K
  Verification: max |T_from_enthalpy - T_exo| at bed = 5.684342e-14 K

nVertLevel 0:

nVertLevel 5:

nVertLevel 9:

[mperego]

It looks good to me.
Thanks for adding the check between the surface and basal temperatures recovered here and the ones computed by Albany!

[matthewhoffman]

Approving based on test results and review from @mperego