[CF-metadata] WRF staggered grids and vertical coordinates

From: Jonathan Gregory <j.m.gregory>
Date: Wed, 28 Jan 2004 08:43:51 +0000

Dear John

Like Karl, I wonder why these lat,lon variables are functions of time. Of
course that increases the storage requirements, although I don't think it
affects the basic argument.

Even if there are 16 ancillary coordinate variables, I do think that is the
right thing to do, because it means the file will be capable of being
interpreted by any application which recognises the coordinates attribute.
If you don't use this mechanism, it is unlikely that most applications will
be able to locate the data.

So the question is whether you also need to record the relation of these
various grids with extra (redundant) metadata. Maybe it would be helpful to
an application, but I'm not sure it's really necessary, is it? As you said
earlier, the methods used are quite straightforward: you interpolate one
field onto the grid of another one, or maybe you interpolate two fields
onto a common grid which uses x from one and y from the other. To do this,
no special machinery is required. All the program needs to know is which
grids are to be used as target for the interpolation. I would argue that's
not metadata, but a convention for how the data should be used - it's not
a property of the dataset but of the program.

Best wishes

Jonathan
Received on Wed Jan 28 2004 - 01:43:51 GMT