Dear Nan > Water velocities are defined more consistently, with eastward_ > northward_ and upward_sea_water_velocity having parallel names/ > definitions, and allowing the e/n terms to be used with or without > a vertical component. ... > I think the latter is a better way to handle platform motion, > because it's more flexible and consistent. It does put the onus > on the user to look for a vertical component if they're going to > calculate speeds
I agree with this. The definitions of the E/N components should not imply that there is, or is not, a vertical component too. > The treatment of air velocity - wind - in CF is a little bit > problematic, IMHO; wind is assumed to be a 2D vector. > If you have a 3-component air velocity record, I'm not sure how you're > supposed to record the e/n components in CF. You use eastward wind, northward wind, and upward air velocity. I think the use of these terms is what you advocate, and the confusing thing is the definition of "wind": "Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component." I think what this means is that we don't use the word "wind" for the vertical component, that's all. This situation arises because this was a case when the standard_name table adopted the common term i.e. wind. If we had said "air velocity" for all components we wouldn't have had the problem. As you know, when we assign standard names it can be an awkward choice between a term normally used and a longer, more consistent and self-explanatory term. Best wishes Jonathan _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
