Bugfix: Fix support for OSI-SAF sea ice concentration data on LAEA grids in CF-compliant NetCDF files

[JohnHalleyGotway]

Describe the Problem

This issue was raised in the second topic of the dtcenter/METplus#2312 discussion. Please see this comment for details.

Expected Behavior

While the sample NetCDF file follows the CF-convention, MET is not properly parsing the LAEA grid from it. This issue is to correct that support. MET should be able to parse CF-compliant LAEA grid definitions. And if the grid specifications do not actually follow the convention, MET should error out with a error message stating as much.

Environment

Describe your runtime environment:
1. Machine: Mac Laptop
2. OS: MacOS
3. Software version number(s): Tested using the main_v11.1 branch of MET

To Reproduce

Describe the steps to reproduce the behavior:
1. Download this file:
ice_conc_nh_ease-125_cont-reproc_201908071200.nc.gz
2. Run plot_data_plane at verbosity level 4:

MET-main_v11.1/bin/plot_data_plane ice_conc_nh_ease-125_cont-reproc_201908071200.nc plot.ps 'name="ice_conc"; level="(0,*,*)";' -v 4

3. Note the incorrect grid definition:

DEBUG 4: Grid information:
DEBUG 4:    Projection: Lambert Azimuthal Equal Area
DEBUG 4:    Nx: 849
DEBUG 4:    Ny: 849
DEBUG 4:    SpheroidName: Undefined
DEBUG 4:    Lat_LL: nan
DEBUG 4:    Lon_LL: nan
DEBUG 4:    Lat_Pole: 90.000
DEBUG 4:    Lon_Pole: -0.000

The Lat_LL and Lon_LL entries should NOT be nan.

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[JohnHalleyGotway]

Discussed the status of this issue at the MET development meeting on Feb 22, 2024. @rgbullock is investigating whether this situation can be fixed through the Proj implementation that will be provided in MET version 12.0.0. We'll revisit this next Thursday, Feb 29th, to determine whether its feasible to provide a fix for this in a MET version 11.1.1 bugfix release, or wait to provide the fix as part of the next major release, version 12.0.0.