Description
### Describe the bug
When using WRF-DART while applying WRF 'lat-lon' map projection for land/atmosphere -- DART misinterprets 'lat-lon' map projection as cassini.
Expectation:
When using WRF 'lat-lon', that DART uses the map_latlon and PROJ_LATLON options in model_mod to perform interpolation
What happens instead:
DART uses map_cassini and PROJ_CASSINI instead. This occurs because WRF assign an integer value of '6' for the 'MAP_PROJ' attribute using map_latlon, whereas DART assigns an integer value of '0' for PROJ_latlon. DART incorrectly calls subroutine llij_cassini instead of llij_latlon, which is the incorrect forward operator.
### Which model(s) are you working with?
Tested with WRF version 3.9 thru 4.5
### Version of DART
Latest tag
### Have you modified the DART code?
No -- but quick fix would be to reassign the integers within DART such that PROJ_LATLON = 6 and map_latlon = 6. Then assign cassini a different integer, such as PROJ_CASSINI = 106 or map_cassini = 106. See misc_definitions_module and
model_mod.f90 for more details.
All other WRF supported map projections are aligned properly with DART -- including lambert, mercator and polar. No changes required. The WRF-DART tutorial using the lambert map projection.
I thought this integer change for the latlon MAP_PROJ occured between WRF version 3 and more recent versions of WRFv4+, and this change was missed during the WRF-DART version 4 tutorial updates, however, both WRFv3 and v4 versions have this integer mismatch with DART.
Bug, first reported by Rui Sun (UCSD).
### Compiling information
Derecho using gfortan