Hi all -
I'm looking for a standard names for wind stress (direction and
magnitude, degree and
N/m^2, respectively), which are outputs of the COARE surface flux algorithm.
I did a search of the standard names and didn't find anything* that
seemed appropriate.
The Wikipedia definition of wind stress is:
wind stress is the shear stress exerted by the wind on the surface
of large bodies of
water. It is the force component parallel to the surface, per unit
area, as applied by
the wind on the water surface.
A search of the email list turned up a discussion of wind stress
divergence and curl, copied
below. I'm almost sure we've discussed this before, but either my email
archive isn't complete
or these terms weren't in the subject lines of the discussion.
I'd like to propose these new names, unless these concepts are already
there using different
terms.
Thanks - Nan Galbraith
* This standard name seems related, but it has a definition that isn't
clear to me at all:
|wind_mixing_energy_flux_into_sea_water (||W m-2):|
||'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.) In accordance with common usage in geophysical
disciplines,
"flux" implies per unit area, called "flux density" in physics.'
On 9/23/16 10:47 AM, Bruce Hackett wrote:
Picking this up again after a long silence.
I have been discussing this with my colleagues at KNMI and have gotten
some comments from Alison Pamment (thanks). The conclusion is that we
would like to revise the suggestion somewhat.
The proposal for the wind stress divergence is essentially unchanged,
we just add the units.
The proposal for the wind stress curl is modified to bring it in line
with what we are producing, which is the vertical component (indeed a
scalar!).
We hope this will be acceptable to the community.
The revised proposal is:
-------------------------------
standard_name: divergence_of_surface_downward_stress
units: N/m^3
Description: 'The divergence is a signed scalar that represents the
magnitude of the 2D surface wind downward stress vector field's source
(positive) or sink (negative) at a given point. The surface called
"surface" means the lower boundary of the atmosphere. "Downward"
indicates a downward flux of momentum, which accelerates the lower
medium along the vector and the upper medium against the vector. The
surface downward stress is the wind stress on the surface.'
--------------------------------
standard_name: vertical_component_of_surface_downward_stress_curl
units: N/m^3
'The vertical component of the stress curl is a signed scalar that
represents the magnitude of the 2D surface wind downward stress vector
field's local anti-clock-wise rotation at a given point; clockwise
rotation is thus given as negative curl. The surface called "surface"
means the lower boundary of the atmosphere. "Downward" indicates a
downward flux of momentum, which accelerates the lower medium along
the vector and the upper medium against the vector. The surface
downward stress is the wind stress on the surface.'
Best regards,
Bruce
2016-03-08 9:37 GMT+01:00 Bruce Hackett <[email protected]
<mailto:[email protected]>>:
Here are proposed definitions provided by my colleague Ad
Stoffelen at KNMI:
-------------------------------
divergence_of_surface_downward_stress
The divergence is a signed scalar that represents the magnitude of
the 2D surface wind downward stress vector field's source
(positive) or sink (negative) at a given point. The surface called
"surface" means the lower boundary of the atmosphere. "Downward"
indicates a downward flux of momentum, which accelerates the lower
medium along the vector and the upper medium against the vector.
The surface downward stress is the wind stress on the surface.
--------------------------------
curl_of_surface_downward_stress
The curl is a signed scalar that represents the magnitude of the
2D surface wind downward stress vector field's local
anti-clock-wise rotation at a given point; clockwise rotation is
thus given as negative curl. The surface called "surface" means
the lower boundary of the atmosphere. "Downward" indicates a
downward flux of momentum, which accelerates the lower medium
along the vector and the upper medium against the vector. The
surface downward stress is the wind stress on the surface.
Best regards,
Bruce
----------------------------------------------------------------------
Message: 1
Date: Tue, 19 Jan 2016 16:41:17 +0000
From: Jonathan Gregory <[email protected]
<mailto:[email protected]>>
To: [email protected] <mailto:[email protected]>
Subject: [CF-metadata] standard_names for wind stress curl, wind
stress divergence
Message-ID: <[email protected]
<mailto:[email protected]>>
Content-Type: text/plain; charset=us-ascii
Dear Bruce
> If there are indeed no standard_names that are appropriate,
I would like to suggest the following:
> divergence_of_surface_downward_stress
> curl_of_surface_downward_stress
I don't think we have named those before and your proposals
look like the
natural choice to me. If you could provide definitions (like
those most
quantities have in the table) and canonical units that will
constitute a
proposal. People may then comment and when it seems that the
discussion is
over, if they are agreed, they'll be added to the list.
Best wishes and thanks
Jonathan
--
2016-03-08 9:37 GMT+01:00 Bruce Hackett <[email protected]
<mailto:[email protected]>>:
Here are proposed definitions provided by my colleague Ad
Stoffelen at KNMI:
-------------------------------
divergence_of_surface_downward_stress
The divergence is a signed scalar that represents the magnitude of
the 2D surface wind downward stress vector field's source
(positive) or sink (negative) at a given point. The surface called
"surface" means the lower boundary of the atmosphere. "Downward"
indicates a downward flux of momentum, which accelerates the lower
medium along the vector and the upper medium against the vector.
The surface downward stress is the wind stress on the surface.
--------------------------------
curl_of_surface_downward_stress
The curl is a signed scalar that represents the magnitude of the
2D surface wind downward stress vector field's local
anti-clock-wise rotation at a given point; clockwise rotation is
thus given as negative curl. The surface called "surface" means
the lower boundary of the atmosphere. "Downward" indicates a
downward flux of momentum, which accelerates the lower medium
along the vector and the upper medium against the vector. The
surface downward stress is the wind stress on the surface.
Best regards,
Bruce
----------------------------------------------------------------------
Message: 1
Date: Tue, 19 Jan 2016 16:41:17 +0000
From: Jonathan Gregory <[email protected]
<mailto:[email protected]>>
To: [email protected] <mailto:[email protected]>
Subject: [CF-metadata] standard_names for wind stress curl, wind
stress divergence
Dear Bruce
> If there are indeed no standard_names that are appropriate,
I would like to suggest the following:
> divergence_of_surface_downward_stress
> curl_of_surface_downward_stress
I don't think we have named those before and your proposals
look like the
natural choice to me. If you could provide definitions (like
those most
quantities have in the table) and canonical units that will
constitute a
proposal. People may then comment and when it seems that the
discussion is
over, if they are agreed, they'll be added to the list.
Best wishes and thanks
Jonathan
--
*******************************************************
* 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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