Hi All,
For reference, a measurement usually referred to as surface air
temperature is a measurement taken at about 2 meters height above the
surface (of the earth or ocean).? It has a standard name
"air_temperature" (which also applies to temperatures higher up in the
atmosphere).? To precisely specify the height above the surface at which
the surface air temperature is measured, a scalar coordinate is defined
with standard_name "height", with the value set to the actual height of
measurement (usually 2 meters, as noted above).? Note that this
near-surface air temperature is different from "surface_temperature"
which is the temperature of the surface itself.
Something similar is done for surface wind speed measurements, but the
height is typically 10 meters, not 2 meters.
In both cases, no special standard name is defined for these
near-surface measurements.
best regards,
Karl
On 9/12/19 9:13 AM, Nan Galbraith wrote:
> Hi all -
>
> I'd like to second (or third ... ) the request for new standard names for
> sea_water_practical_salinity_at_sea_floor and
> sea_water_temperature_at_sea_floor.
>
> In the OceanSITES project, we deploy CTDs on mooring anchors, and it
> would be good
> to be able to find these records, among all the water temperature and
> practical salinity
> data sets on our servers. We supply a measurement depth, but it isn't
> useful for this
> search, since the water depth isn't mandatory in our format spec.
>
> These records are not exactly on the sea floor, but within a few
> meters; do we need to
> apply some limit to the distance? I'm thinking about the various
> sea_surface_temperature
> variants, surface_skin and surface_subskin, but I'm assuming this
> isn't needed for sea
> floor measurements.
>
> Thanks - Nan
>
>
> On 9/10/19 1:59 PM, Lowry, Roy K. wrote:
>> Hi again,
>>
>> I place great weight on the phrase 'where appropriate'. If a model
>> works out electrical conductivity and then uses the PSS-78 algorithms
>> to compute the salinity then using 'practical salinity' would be
>> appropriate, but these are far from the norm!!!? It's observational
>> measurements where we really need to be careful about the types of
>> salinity, but I've yet to see a measurements data set where bottom
>> salinities are tagged differently from the salinities measured
>> elsewhere in the water column. Consequently I don't see the need for
>> the new name.
>>
>> Cheers, Roy.
>>
>> I have now retired but will continue to be active through an Emeritus
>> Fellowship using this e-mail address.
>>
>>
>> ------------------------------------------------------------------------
>> *From:* Andrew Barna <abarna at ucsd.edu>
>> *Sent:* 10 September 2019 18:47
>> *Subject:* Re: [CF-metadata] new variable name request
>> Thanks Roy,
>>
>> All the existing ?sea_water_salinity? names have the sentence "The
>> more precise standard names should be used where appropriate for both
>> modelled and observed salinities.? So it think it was worth the ask
>> if they know.
>>
>> -Barna
>>
>> > On 2019-09-10, at 07:42, Lowry, Roy K. <rkl at bodc.ac.uk> wrote:
>> >
>> > Dear Barna,
>> >
>> > Perhaps the existing Standard Name would suffice for Cathy's needs
>> as she is labelling model output and the models in my experience do
>> not work to a specific measurement scale. This is because boundary
>> condition and assimilation data sets can include measurements of more
>> than one type in order to provide adequate coverage.
>> >
>> > Cheers, Roy.
>> >
>> >
>> > From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of
>> Andrew Barna <abarna at ucsd.edu>
>> > Sent: 10 September 2019 18:23
>> > Subject: Re: [CF-metadata] new variable name request
>> >
>> > Hi Cathy,
>> >
>> > There is already the name `sea_water_salinity_at_sea_floor` in the
>> CF standard name list. However, if you know the scale you are
>> calculating, a new name should be added to indicate this:
>> > sea_water_practical_salinity_at_sea_floor if using PSS-78
>> > or
>> > sea_water_absolute_salinity_at_sea_floor if using TEOS-10
>> >
>> > I can come up with some definitions if you would like to have
>> either of these proposed to the list.
>> > -Barna
>> >
>> >
>> > > On 2019-09-10, at 07:04, Cathy Smith <cathy.smith at noaa.gov> wrote:
>> > >
>> > > Thanks. I will use that variable.
>> > >
>> > > I also calculated salinity of the ocean floor. Same question.
>> > >
>> > > Cathy
>> > >
>> > > On 9/9/19 3:44 PM, Andrew Barna wrote:
>> > >> Hi Cathy,
>> > >>
>> > >> There is the name `sea_water_potential_temperature_at_sea_floor`
>> with the following definition:
>> > >> Potential temperature is the temperature a parcel of air or sea
>> water would have if moved adiabatically to sea level pressure. The
>> potential temperature at the sea floor is that adjacent to the ocean
>> bottom, which would be the deepest grid cell in an ocean model.
>> > >>
>> > >> From what I can tell, there is no ?in situ? sea water
>> temperature name at the sea floor. I?d suggest the following name for
>> this parameter with canonical units K:
>> > >> `sea_water_temperature_at_sea_floor`
>> > >>
>> > >> Here is a possible definition basically modifying the above to
>> remove the ?potential? parts:
>> > >>
>> > >> Sea water temperature is the in situ temperature of the sea
>> water. The temperature at the sea floor is that adjacent to the ocean
>> bottom, which would be the deepest grid cell in an ocean model.
>> > >>
>> > >> There should probably also be a modification of the existing
>> sea_water_temperature definition to include this new name if it is
>> accepted:
>> > >>
>> > >> The sentence:
>> > >> "There are standard names for sea_surface_temperature,
>> sea_surface_skin_temperature, sea_surface_subskin_temperature and
>> sea_surface_foundation_temperature which can be used to describe data
>> located at the specified surfaces.?
>> > >>
>> > >> Should be changed to:
>> > >>
>> > >> "There are standard names for sea_surface_temperature,
>> sea_surface_skin_temperature, sea_surface_subskin_temperature,
>> sea_surface_foundation_temperature, and
>> sea_water_temperature_at_sea_floor which can be used to describe data
>> located at the specified surfaces.?
>> > >>
>> > >> -Barna
>> > >>
>> > >>> On 2019-09-09, at 11:23, Cathy Smith <cathy.smith at noaa.gov> wrote:
>> > >>>
>> > >>> All
>> > >>>
>> > >>> I have a new variable request; bottom temperature. It is the
>> temperature of the ocean floor (or the last level of a multi level
>> ocean dataset). I searched and was unable to find it or a variable
>> with "bottom" or synomyn as a level. I welcome being pointed out
>> where I missed it.
>> > >>>
>> > >>> It is an important variable for fish and aquatic populations
>> near coasts (or very shallow oceans).
>> > >>>
>> > >>> http://glossary.ametsoc.org/wiki/Bottom_temperature
>> > >>>
>> > >>> https://www.frontiersin.org/articles/10.3389/fmars.2019.00030/full
>> > >>>
>>
>>
>
Received on Thu Sep 12 2019 - 10:56:41 BST
