Dear Nan
Including upward/downward in the standard names of vertical components of
vectors was a design decision when we started on the compiling the table,
as with northward/southward, eastward/westward and any quantity which has
a direction associated with it. Yes, there are other pairs where both senses
have names. The reason is to make sure the sign convention is recorded. If
it was a separate attribute, there's a reasonable chance it would not be
included, or might be wrong.
It sounds like you have a different use-case, with a sensor that measures a
velocity component which isn't strictly vertical. We could give that a
different name (i.e. component parallel to the instrument orientation, with
again the need to indicate the sign convention somehow).
Best wishes
Jonathan
----- Forwarded message from Nan Galbraith <ngalbraith at whoi.edu> -----
> Date: Tue, 1 Mar 2016 10:31:25 -0500
> From: Nan Galbraith <ngalbraith at whoi.edu>
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] New standard_name: downward_air_velocity
> User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:38.0)
> Gecko/20100101 Thunderbird/38.6.0
>
> I agree, it's consistent, and may as well be added.
>
> That said, I'm not sure why we don't use 'vertical' for the vertical
> component of
> all these 3d velocity vectors, and then recommend an attribute that
> would specify
> the direction (up- or down-ward). I didn't have time to check
> whether we have
> any standard names that exist in both the upward and downward form ( I'm
> not really sure if that would be a problem, any way, but it seems
> like it might be).
>
> The reason this is important in my data is that some current meters
> and profilers
> output a vertical velocity where the direction depends on the
> orientation of the
> instrument. The vertical velocity is also a measure of measurement
> quality in those
> data sets, since excessive vertical values usually indicate an error
> in the other
> vectors.
>
> Cheers - Nan
>
> On 2/26/16 2:46 PM, Jonathan Gregory wrote:
> >Dear Ken
> >
> >That looks good to me - clearly consistent with existing names.
> >
> >Best wishes
> >
> >Jonathan
> >
> >----- Forwarded message from "Kehoe, Kenneth E." <kkehoe at ou.edu> -----
> >
> >>Date: Thu, 25 Feb 2016 20:31:31 +0000
> >>From: "Kehoe, Kenneth E." <kkehoe at ou.edu>
> >>To: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>
> >>Subject: [CF-metadata] New standard_name: downward_air_velocity
> >>
> >>CF,
> >>
> >>Can we add downward_air_velocity to be the counter to the existing upward_air_velocity.
> >>
> >>Definition = A velocity is a vector quantity. ?Downward" indicates a vector component which is positive when directed downward (negative upward). Downward air velocity is the vertical component of the 3D air velocity vector.
> >>
> >>Thanks,
> >>
> >>Ken
> >>
> >>
>
>
> --
> *******************************************************
> * Nan Galbraith Information Systems Specialist *
> * Upper Ocean Processes Group Mail Stop 29 *
> * Woods Hole Oceanographic Institution *
> * Woods Hole, MA 02543 (508) 289-2444 *
> *******************************************************
>
>
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----- End forwarded message -----
Received on Tue Mar 01 2016 - 08:42:32 GMT
