There have not been any responses to this post in the last 10 days. I know that this is a dangerous philosophy, but can I suggest that, in this case, silence equals consent?
If it is, I would like to see these amendments in the standard_name publications as soon as possible. Would this cause concern? many thanks mark -----Original Message----- From: [email protected] on behalf of Hedley, Mark Sent: Thu 05/04/2012 17:35 To: [email protected] Subject: [CF-metadata] identification of vector components There is a statement in the definition of many standard names which are used for vector component definitions, e.g.: x_wind alias: grid_eastward_wind "x" indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) I think that the statement 'when this is not true longitude' is problematic, particularly for software converting from other formats, where x indicates the grid i direction, independent of rotation or projection. I do not think it is the place for standard_name to limit the use of the term 'x' to cases where the horizontal coordinate reference system is not 'true latitude longitude' I propose that these terms be removed from all standard names which have 'x' or 'y' as a modifier. This would enable all x-ward and y-ward definitions to be used, independent of the grid_mapping, as standard names. eastward and northward remain useful modifiers as many models may choose to output eastward vector components where east is not the x direction for the model grid. The work on vector containers in: https://cf-pcmdi.llnl.gov/trac/ticket/79 has indicated a good way forward for identifying vector components, and identifying that vectors are with respect to a grid_mapping. I think this proposed change would interface nicely to the proposal in ticket 79 How would this proposal be viewed by the community? mark _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
