Aloha CFers,
Is it correct to add a cell_methods = "time: mean" attribute to the
time coordinate when the coordinate is averaged over time?
NCO's ncra does this (though the NERC CF checker doesn't like it).
It's clear from the CF docs that ncra time-averaging a variable like
wind(time) from an array to a degenerate (size 1) array should
add a cell_methods = "time: mean" attribute to wind.
Yet should it add cell_methods to the time coordinate itself?
My take is that it should. The time_bounds variable, if any,
will show the original extent of the temporal range, and the time
coordinate value contains the mean of the original range.
Yet an NCO user is making a good case that cell_methods are only
for non-coordinate variables. His point is that many variables with
different cell_methods can all contain the same coordinate, so that
the coordinate should not have cell_methods. My response is that
cell_methods refers to the bounds variable of the coordinate, not
the coordinate values themselves.
Is the question clear? If not, I can supply CDL...
Mahalo,
Charlie
p.s. the CF list archives on the CF homepage poinst to
http://mailman.cgd.ucar.edu/pipermail/cf-metadata
and that URL currently (and for the past ~week) yields this error:
The requested URL /pipermail/cf-metadata/ was not found on this server.
--
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(
Received on Sun May 31 2015 - 18:17:35 BST
