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<font face="Times New Roman">Dear CMOR users,</font><br>
<br>
It has been brought to our attention that the CF checker (which is
different from the CMOR checker) traps an error in CMOR-produced
files indicating non-compliance with the CF conventions. The error
is that the cell_measures attribute is defined, but the area and/or
volume data is not contained in the file. [We have included a
non-CF attribute called "associated_files" that points to the files
containing area/volume.] Still, in order to not confuse
CF-compliant software we plan to immediately release a new version
of CMOR in which the "cell_measures" attribute is replaced by a
non-CF attribute named "ext_cell_measures" (indicating that the
area/volume data is externally available).<br>
<br>
Also, some groups have reported that not all their variables are
carried on the same grid. (For example, sometimes the u and v
fields are staggered relative to T.) In this case it would be
necessary to have more than one set of areas associated with the
model, and this is not currently possible since only areacella,
areacello, and volcello are defined in the CMIP5 request for model
output. We have therefore decided to include an option for CMOR
users to suppress writing of the ext_cell_measures attribute when it
would point to areacella or areacello incorrectly. The user would
in effect be allowed one set of areas to be associated with the
atmospheric model and one set of areas/volumes to be associated with
the ocean models. The user would suppress the ext_cell_measures
attribute (and areacella, areacello, volcello would not appear in
the "associated_files" attribute) for any variables where these
areas/volumes would be incorrect.<br>
<br>
We hope this is acceptable.<br>
<br>
Best regards,<br>
Karl and Charles<br>
<br>
<br>
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