Thanks, Jonathan - This makes perfect sense now. Instruments may output
vertical velocity because the manufacturer doesn't know the orientation of
the deployment in advance. It seems fine for the data writer to chose the
appropriate name when publishing the data in CF.
Thanks again - Nan
On 3/1/16 10:42 AM, Jonathan Gregory wrote:
> 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 *
>> *******************************************************
>>
>>
>> _______________________________________________
>> CF-metadata mailing list
>> CF-metadata at cgd.ucar.edu
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> ----- End forwarded message -----
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
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--
*******************************************************
* Nan Galbraith Information Systems Specialist *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 (508) 289-2444 *
*******************************************************
Received on Thu Mar 03 2016 - 07:56:28 GMT
