Improve procedure for creating new initial conditions files for LII tests

**Bill Sacks < sacks@ucar.edu > - 2017-07-03 14:04:11 -0600**
**Bugzilla Id:** [2483](http://bugz.cgd.ucar.edu/show_bug.cgi?id=2483)
**Bugzilla CC:** andre@ucar.edu, erik@ucar.edu, rfisher@ucar.edu,

Currently, to produce new initial conditions files for LII tests (when the old file becomes incompatible with the new model configuration), we run a case with use_init_interp = .true. and take the finidat_interp_dest.nc file to produce the new initial conditions file. This feels a bit risky to me: It feels like there could be cases where the LII test will pass with a file created in this way, but would fail with an initial conditions file that was generated from a multi-year spinup and was not run through init_interp.

One example I can think of is: If a variable mistakenly has interp_flag='skip', then its value on finidat_interp_dest.nc would be its cold start value. Then a future LII test would fail to catch that it had interp_flag='skip', because the value would be the cold start value in both cases of the LII test. (I'm not super-concerned about this, because the LII test would presumably have been failing before the recreation of initial conditions in this scenario.)

So it feels like we should come up with a procedure for recreating LII initial conditions that gives us files that have been through at least a few years of spinup, rather than using the finidat_interp_dest files for this purpose.