[CF-metadata] Fwd: Re: New standard names for NEMO ocean model output

[Jonathan Gregory]

Dear Eric

Yes, I see what you mean. If we could clarify the "defined by" part, would you
be content to describe the turbocline as a mixed layer (with appropriate
definition)?

Best wishes

Jonathan

> - ocean_turbocline_thickness in m
> The turbocline thickness is similar to the mixed layer thickness but is 
> estimated in models as the thickness at which the vertical eddy diffusivity 
> coefficient (resulting from the vertical physics alone) falls below a given 
> value defined locally.
> 
> You mentioned that this is the same as 
> ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity.
> 
> But the definition for this one in the CF table is
> 
> "The ocean mixed layer is the upper part of the ocean, regarded as being 
> well-mixed. The base of the mixed layer defined by temperature, sigma, 
> sigma_theta, or vertical diffusivity is the level at which the quantity 
> indicated differs from its surface value by a certain amount. The amount by 
> which the quantity differs can be specified by a scalar coordinate variable."
> 
> Unlike with temperature or density criteria, the turbocline thickness is not 
> estimated based on the difference with respect to the vertical diffusivity at 
> the surface. As written in the definition we gave you, when the vertical 
> diffusivity falls below a given value defined locally then we are at the 
> turbocline depth.
> 
> #
> 
> I hope this helps.
> 
> Best regards,
> 
> Eric
> 
> 
>  
> 
> - Original Message -
> From: "Kevin Marsh" 
> To: "Eric Boisseson" 
> Sent: Tuesday, 13 December, 2016 14:35:48
> Subject: Fwd: [CF-metadata]  New standard names for NEMO ocean model output
> 
> Hi Eric,
> some feedback on your feedback...feel free to send any responses directly to 
> the list, or to me if you prefer and i will send the comments to the list.
> I think that he's happy with 1, so only need input for 2. and 3.,
> Thanks,
> Kevin
> 
> - Forwarded Message -
> From: "j m gregory" 
> To: cf-metadata@cgd.ucar.edu
> Sent: Tuesday, 13 December, 2016 13:56:41
> Subject: [CF-metadata]  New standard names for NEMO ocean model output
> 
> Dear Kevin
> 
> > 1. bottom_pressure_equivalent_height (m) 
> > 3. ocean_steric_height (m)
> >  
> > The steric height is estimated as the vertical integral of the density 
> > (relative to a reference density where T=0K and S=35psu). The bottom 
> > pressure is the mass of the water column at a given location. 
> 
> Ah, I see.
> 
> For
> > 3. ocean_steric_height_above_sea_level (m)
> I would suggest
> > The ocean steric height above sea level measures the change in thickness of 
> > a column of water when its temperature and salinity are changed from 
> > standard values of 0°C and 0.035 to the actual values
> 
> > The bottom pressure equivalent height is estimated indirectly as the 
> > difference between the steric height and the sea level.
> 
> I don't follow that, which sounds like the definition of ocean steric height
> again. However your alternative statement of its being the mass of the column
> makes sense to me. Going with the latter definition, I would suggest
> 
> sea_water_mass_per_unit_area_expressed_as_thickness
> 
> and presumably you have to state a standard density to be used in this
> conversion - what is that? NB sea_water_mass_per_unit_area (kg m-2) is already
> a standard name.
> 
> > 2. Instead of "ocean_turbocline_depth (m)" we suggest:
> > ocean_turbocline_thickness (m)
> > 'The turbocline thickness is similar to the mixed layer thickness but is 
> > estimated in models as the thickness at which the vertical eddy diffusivity 
> > coefficient (resulting from the vertical physics alone) falls below a given 
> > value defined locally.'
> 
> Is there a difference between that and the existing
> ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity
> ?
> 
> > ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (K 
> > s-1)
> > 
> > 'This term is estimated as the deviation of the local sea water potential 
> > temperature from an ocean model wrt an observation-based climatology (eg 
> > World Ocean Database) weighted by a user-specified relaxation coefficient 
> > in s-1 (1/(relaxation timescale)). The relaxation coefficient depends on 
> > the timescale on which the correction is applied.'
> 
> It seems to me that the last sentence is probably not necessary, since the
> previous sentence says the same.
> 
> Best wishes and thanks
> 
> Jonathan
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Re: [CF-metadata] Proposal to introduce three new standard names for nitrogen deposition

[Daniel . Neumann]

Dear all,

I handed in a proposal for three new standard names for nitrogen deposition. 
After Jonathan's reply there was no further feedback. Therefore, I would like 
to bring this proposal back to your attention and - if there are no objections 
- to the official proposal list. 

The proposed standard names were
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_dry_deposition
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_wet_deposition
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_deposition

The reason was:
The total nitrogen deposition into water bodies is an important parameter when 
Eutrophication of water bodies and nutrient contribution from rivers and the 
atmosphere are evaluated. This parameter is no primary model output parameter 
but it is derived from the deposition of all nitrogen compounds. When providing 
nitrogen deposition data to ecosystem modelers it is reasonable to provide 
'nitrogen deposition' instead of 'nitrogen wet deposition' and 'nitrogen dry 
deposition' separately because algae do not care about the type of deposition.
Instead of providing "total nitrogen deposition" one could also provide wet and 
dry deposition of "ammonium + ammonia + noy + nitrate". However, this yields 
files that are eight times as height as necessary.
Therefore, standard names for nitrogen wet, dry and total deposition should be 
introduced.

It might be debatable to also introduce standard names for 'oxidized nitrogen 
deposition' (noy + nitrate) or 'reduced nitrogen deposition' (ammonia + 
ammonium). This would mean 9 nine standard names ([wet, dry, total] x [reduced, 
oxidized, total]). I would interested on you feedback on that option. 

Please find the exact descriptions and units below.

Cheers,
Daniel


1)
standard name:
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_dry_deposition

unit:
kg m-2 s-1

description:
"Content" indicates a quantity per unit area. The "atmosphere content" of a 
quantity refers to the vertical integral from the surface to the top of the 
atmosphere. For the content between specified levels in the atmosphere, 
standard names including "content_of_atmosphere_layer" are used. 
"tendency_of_X" means derivative of X with respect to time. The specification 
of a physical process by the phrase "due_to_" process means that the quantity 
named is a single term in a sum of terms which together compose the general 
quantity named by omitting the phrase. "dry_deposition" is the sum of turbulent 
deposition and gravitational settling. "Nitrogen" summarizes all chemical 
species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen 
compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen 
dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrage (NO3-), 
peroxynitric acid (HNO4), ammoina (NH3), ammonium (NH4+), bromine nitrate 
(BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably 
peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. 
The list of individual species that are included in this quantity can vary 
between models. Where possible, the data variable should be accompanied by a 
complete description of the species represented, for example, by using a 
comment attribute.


2)
standardname:
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_wet_deposition

unit:
kg m-2 s-1

description:
"Content" indicates a quantity per unit area. The "atmosphere content" of a 
quantity refers to the vertical integral from the surface to the top of the 
atmosphere. For the content between specified levels in the atmosphere, 
standard names including "content_of_atmosphere_layer" are used. 
"tendency_of_X" means derivative of X with respect to time. The specification 
of a physical process by the phrase "due_to_" process means that the quantity 
named is a single term in a sum of terms which together compose the general 
quantity named by omitting the phrase. "wet_deposition" means deposition by 
precipitation. "Nitrogen" summarizes all chemical species containing nitrogen 
atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic 
nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen 
pentoxide (N2O5), nitric acid (HNO3), nitrage (NO3-), peroxynitric acid (HNO4), 
ammoina (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate 
(ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes 
referred to as PAN, (CH3COO2NO2)) are included. The list of individual species 
that are included in this quantity can vary between models. Where possible, the 
data variable should be accompanied by a complete description of the species 
represented, for example, by using a comment attribute.


3)
standardname:
tendency_of_atmosphere_mass_content_of_nitrogen_due_to_deposition

unit:
kg m-2 s-1

description:
"Content" indicates a quantity per unit area. The "atmosphere content" of a 
quantity refers to the vertical 

[CF-metadata] New standard names for NEMO ocean model output

[Jonathan Gregory]

Dear Kevin

> 1. bottom_pressure_equivalent_height (m) 
> 3. ocean_steric_height (m)
>  
> The steric height is estimated as the vertical integral of the density 
> (relative to a reference density where T=0K and S=35psu). The bottom pressure 
> is the mass of the water column at a given location. 

Ah, I see.

For
> 3. ocean_steric_height_above_sea_level (m)
I would suggest
> The ocean steric height above sea level measures the change in thickness of a 
> column of water when its temperature and salinity are changed from standard 
> values of 0°C and 0.035 to the actual values

> The bottom pressure equivalent height is estimated indirectly as the 
> difference between the steric height and the sea level.

I don't follow that, which sounds like the definition of ocean steric height
again. However your alternative statement of its being the mass of the column
makes sense to me. Going with the latter definition, I would suggest

sea_water_mass_per_unit_area_expressed_as_thickness

and presumably you have to state a standard density to be used in this
conversion - what is that? NB sea_water_mass_per_unit_area (kg m-2) is already
a standard name.

> 2. Instead of "ocean_turbocline_depth (m)" we suggest:
> ocean_turbocline_thickness (m)
> 'The turbocline thickness is similar to the mixed layer thickness but is 
> estimated in models as the thickness at which the vertical eddy diffusivity 
> coefficient (resulting from the vertical physics alone) falls below a given 
> value defined locally.'

Is there a difference between that and the existing
ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity
?

> ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (K 
> s-1)
> 
> 'This term is estimated as the deviation of the local sea water potential 
> temperature from an ocean model wrt an observation-based climatology (eg 
> World Ocean Database) weighted by a user-specified relaxation coefficient in 
> s-1 (1/(relaxation timescale)). The relaxation coefficient depends on the 
> timescale on which the correction is applied.'

It seems to me that the last sentence is probably not necessary, since the
previous sentence says the same.

Best wishes and thanks

Jonathan
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[CF-metadata] New standard name for probability of cloud

[Jonathan Gregory]

Dear Sara

That makes sense to me. Given what the guidelines say, maybe we should change
thunderstorm_probability to probability_of_thundstorm. It is the only existing
probability standard name, I see.

Best wishes

Jonathan

- Forwarded message from Hörnquist Sara  -

> Date: Tue, 13 Dec 2016 11:40:59 +
> From: Hörnquist Sara 
> To: "cf-metadata@cgd.ucar.edu" 
> Subject: [CF-metadata] New standard name for probability of cloud
> 
> Dear all,
> 
>  I'd like to suggest "probability_of_cloud", alternatively 
> "cloud_probability", as a new standard name.
> 
> There is a demand from many users (e.g. from the producers of sea surface 
> temperatures, SST) to shift from a binary cloud mask in satellite derived 
> products to a cloud mask expressed as a cloud probability. This would better 
> account for uncertainties in the derived cloud information and would allow 
> for that those uncertainties can be used in downstream processing for 
> assessing the impacts on other products (like SST).
> 
> The new standard nam should follow the structure of 
> 'thunderstorm_probability':
> "probability_of_X" means the chance that X is true or of at least one 
> occurrence of X. Space and time coordinates must be used to indicate the area 
> and time-interval to which a probability applies.
> 
> The unit should be either 'percent' or '1'.
> 
> Best regards,
> Sara Hornquist

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Re: [CF-metadata] New standard names for NEMO ocean model output

[Kevin Marsh]

Hi Jonathan,
many thanks for your comments. I've been spoken to members of our NEMO team and 
their responses are below.

**
For 
1. bottom_pressure_equivalent_height (m) 
'Difference between the sea level height and the ocean steric height.'

and 

3. ocean_steric_height (m)
'The steric measures the height by which a column of water with standard 
temperature T=0°C and salinity S=35.0 expands if its temperature and salinity 
are changed to the observed values.'

The idea behind these two variables is that local sea level variations can be 
divided into volume changes (or steric changes) and mass changes (visible in 
the eq bottom pressure height).
 
The steric height is estimated as the vertical integral of the density 
(relative to a reference density where T=0K and S=35psu). The bottom pressure 
is the mass of the water column at a given location. 

The bottom pressure equivalent height is estimated indirectly as the difference 
between the steric height and the sea level. This is  just a diagnostic 
variable we use to check the mass budget in our system.

(we'll gladly accept you suggestion, and if 'ocean_steric_height' is a 
thickness we'd be happy to change it to 'ocean_steric_thickness' as long as the 
definition is correctly stated) 

so we suggest:

1. bottom_pressure_equivalent_height (m) 
'Difference between the sea level height and the ocean steric height above sea 
level.'

3. ocean_steric_height_above_sea_level (m)
'The steric measures the height by which a column of water with standard 
temperature T=0°C and salinity S=35.0 expands if its temperature and salinity 
are changed to the observed values.'

**

2. Instead of "ocean_turbocline_depth (m)" we suggest:

ocean_turbocline_thickness (m)
'The turbocline thickness is similar to the mixed layer thickness but is 
estimated in models as the thickness at which the vertical eddy diffusivity 
coefficient (resulting from the vertical physics alone) falls below a given 
value defined locally.'

**
6. temperature_profile_anomaly_correction (K s-1)
This is a temperature difference in K weighted by a relaxation coefficient in 
s-1 (1/(relaxation timescale)). The relaxation timescale represents how 
strongly you want your model to be close to climatology.

we would be happy with your suggestion:

ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (K s-1)

'This term is estimated as the deviation of the local sea water potential 
temperature from an ocean model wrt an observation-based climatology (eg World 
Ocean Database) weighted by a user-specified relaxation coefficient in s-1 
(1/(relaxation timescale)). The relaxation coefficient depends on the timescale 
on which the correction is applied.'

**

Thanks,
Kevin

- Original Message -
From: "j m gregory" 
To: cf-metadata@cgd.ucar.edu
Cc: "Kevin Marsh" 
Sent: Thursday, 24 November, 2016 17:09:18
Subject: Re: [CF-metadata] New standard names for NEMO ocean model output

Dear Kevin and Alison

> 1. bottom_pressure_equivalent_height (m) 
> 'Difference between the sea level height and the ocean steric height.' 

Is that really what it means? The ocean steric height is already a difference
from sea level by definition (see below). It sounds as though this ought to
mean the ocean bottom pressure converted into a thickness of water of some
standard density.

> 2. ocean_turbocline_depth (m) 
> 'The turbocline depth is similar to the mixed layer depth but is estimated in 
> models as the depth at which the vertical eddy diffusivity coefficient 
> (resulting from the vertical physics alone) fall below a given value defined 
> locally.

For consistent with the mixed layer names, this should perhaps be thickness,
rather than depth e.g. ocean_mixed_layer_thickness.

> 3. ocean_steric_height (m)
> 'The steric measures the height by which a column of water with standard 
> temperature T=0°C and salinity S=35.0 expands if its temperature and salinity 
> are changed to the observed values.'

I have found that definition in papers too. It's actually a thickness, as
Alison notes, but we could maybe call it ocean_steric_height_above_sea_level,
which would be consistent with some other std names.

> 6. temperature_profile_anomaly_correction (K s-1)
> 'Correction term estimated as the deviation the local sea water potential 
> temperature from an ocean model wrt to an observation-based climatology (eg 
> World Ocean Database) multiplied by an user-specified relaxation coefficient. 
> The relaxation coefficient depends on the timescale on which the correction 
> is applied.'

I think there are number of problems with this name. (a) It should be
sea_water_potential_temperature, not just temperature, (b) profile is
not really part of the definition of the quantity - it depends on depth,
but standard names do not usually indicate which coordinates are relevant,
(c)