When would dx and dy not be equal?

[William.Hatheway]

In the best practices page it says that the dx and dy values are recommended to be equal. Is there a time when they are not?

dx and dy

Grid distance (or grid resolution) in the x and y directions. This is given in meters for the Lambert, Polar, and Mercator projections. For the 'lat-lon' projection, this is given in degrees latitude. Only the coarse domain resolution needs to be specified, as nest domains will be calculated based on parent_grid_ratio. Best Practice It is recommended that dx and dy have the same value for Mercator, Polar, and Lambert projections. See the description for parent_grid_ratio for relevant/useful information for this parameter.

 

[Ming Chen]

For lat-lon grids, dx and dy could be different. however, they should be as close as possible.

 

[William.Hatheway]

For lat-lon grids, dx and dy could be different. however, they should be as close as possible.

So for the others they should always be equal?

 

[Ming Chen]

Yes that is correct.

 

[William.Hatheway]

Yes that is correct.

is it possible to clarify this in the best practices page?

recommended is a little vague and could lead to confusion that it isn't required.