Verify units of dx and dy as returned by bmi_noahowp%get_grid_spacing

[GreyREvenson]

Current behavior

Calling bmi_noahowp%get_grid_spacing returns (/model%domaingrid%dy, model%domaingrid%dx/) (i.e., via bmi_grid%spacing). This behavior is consistent with BMI 2.0 specifications. However, as the units of dx and dy are not specified in the BMI 2.0 documentation, there is ambiguity regarding the appropriateness of the current implementation.

When executed in standalone (outside NextGen), dx and dy are read-into the model via the required domain attributes NetCDF file (which is expected to have global attributes dx and dy). The example attributes file (i.e., data/NorthForkAttributes.nc) contains a subset of the NWM 3.0 grid for the North Fork (WY) CAMELS test basin; hence, dx = dy = 1 km.

Suggested changes

Verify current implementation of bmi_noahowp%get_grid_spacing or amend implementation of dx and dy as needed.

[GreyREvenson]

@drakest123 Care to expand upon or edit this issue?