Re: [ferret_users] Edges and @AVG

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Alexander and Ferret fans,

On Wed, Feb 26, 2020 at 7:15 AM Alexander Audet <alexander.c.audet@xxxxxxxxx> wrote:

As far as I can tell (link) although the monthly means are timestamped at the first of the month and seem to be centered there, they actually represent the average value of the month instead 1/2 the last and 1/2 the named month. I am still confused about this, so I could be wrong.

If this netCDF file was created by some respectable organization, you may want to file a bug report.  This error affects a lot of users.  The best netCDF configuration for a monthly-mean dataset is, I think, such that

- Each monthly mean is defined at the center of the month.

- The "time_bnds" coordinate variable correctly specifies the beginning and end of each month ( http://cfconventions.org/cf-conventions/cf-conventions.html  ).

Having said all that, it all depends on how accurate you want your seasonal means to be.  For many use cases, the simple (unweighted) average may be fine.  In that case, the 3-point boxcar average (is that @SBX ?) on the L axis will do.

Regards,

Ryo