Dear Beate,
Apologies for the time taken to respond to your requests - I am including here my responses to your 10 April email. My replies to your more recent requests will follow shortly.
> 1. > snow_basal_heat_flux, Snow basal heat flux, W m-2
> Can this be called
> upward|downward_heat_flux_at_ground_level_in_snow
> The corresponding quantity _in_soil is the ground heat flux.
> A: still open
I note that the names
upward|downward_heat_flux_at_ground_level_in_snow
went into the standard name table in the week beginning 27 March - I am unsure whether this request is still outstanding.
> 2. > atmosphere_eastward|northward_stress_due_to_diffusion:Pa
> Are these momentum fluxes directed upwards or downward i.e. tending to
> accelerate the atmosphere below or above the level on which they are given?
> (I realise this is an ambiguity about the gravity-wave stresses too.) Since
> stresses are tensors, they need two signed directions to specify them.
> A: still open
> 3. > soil_suction_at_saturation; Saturation soil suction; m
> I am not sufficiently expert to define this. Could you please supply a
> definition of soil suction?
> A: http://www.geo-observations.com/Information/Whatissoilsuction.html
> It is used for parameterization of land surface processes in models:
> http://www.lmd.jussieu.fr/pcmdi-mirror/modeldoc/amip2/ukmo_98a/ukmo_a.html
Thank you for the references. I suggest modifying this name slightly to
total_soil_suction_at_saturation; Pa
> 4. > soil_texture; fraction of sand, clay and silt; 1
> We have recently added a string-valued quantity soil_type to identify types
> such as you list. It looks as if you would like to specify some parameter as
> a function of soil type. Is it the mass fraction of the soil?
> A: In the 'texture triangle'
> (http://www.pedosphere.com/resources/bulkdensity/triangle_us.cfm) there are marked areas > for each soil type, assessing the soil type depending on the volume percentages
> of components.
According to the reference you provide the soil texture is defined by separately recording the percentages of sand, clay and silt. Therefore I suggest we have 3 standard names to represent this quantity:
volume_fraction_of_sand_in_soil; 1
volume_fraction_of_clay_in_soil; 1
volume_fraction_of_silt_in_soil; 1
> 5. > stomatal resistance depends on vegetation type, it is not clear to me, how
> > to include min and max into standard name:
> > stomatal_resistance; Maximum stomatal resistance; s m-1
> > stomatal_resistance; Minimum stomatal resistance; s m-1
> I suppose this could be indicated by cell_methods "vegetation_type: maximum".
> We have not got standard names for stomatal resistance and vegetation type.
> Are you proposing these?
> A: Yes, stomatal_resistance is the proposal.
> Each vegetation type has its maximum and its minimum, depending on the situation (water > supply and temperature).
I have spoken to Jonathan about this proposal and realised that he and I were placing different interpretations on what is being requested. If you wish to represent the maximum and minimum values of stomatal resistance occurring within a model grid box containing a number of different vegetation types then Jonathan's idea of using cell_methods would seem the logical way to go. If, however, you are wishing to describe the range of values that stomatal resistance may take as a function of vegetation type then this may be better specified using a standard name modifier. Please can you clarify which of these interpretations is correct?
>6. > surface_direct_downwelling_photosynthetic_radiative_flux; W m-2
> > surface_diffuse_downwelling_photosynthetic_radiative_flux; W m-2
> Is it correct that you mean the vertically downward component of the flux
> directly from the sun in the first case, while the second means
> surface_downwelling_photosynthetic_radiative_flux minus
> surface_direct_downwelling_photosynthetic_radiative_flux?
> A: yes
For consistency with other names I suggest we make these
surface_direct_downwelling_photosynthetic_radiative_flux_in_air; W m-2
surface_diffuse_downwelling_photosynthetic_radiative_flux_in_air; W m-2
> 7. > tendency_of_atmosphere_water_vapor_content_due_to_stable_convection:kg m-2 s-1
> > tendency_of_atmosphere_water_vapor_content_due_to_turbulence:kg m-2 s-1
> > tendency_of_water_vapor_content_of_atmosphere_layer_due_to_stable_convection:kg m-2 s-> 1
> > tendency_of_water_vapor_content_of_atmosphere_layer_due_to_turbulence:kg m-2 s-1
> Could you define what "turbulence" and "stable convection" mean, please?
> A by A.Ruane: turbulence is "turbulent_mixing" and "stable_convection" should
> really be "stable_moistening" or "non_convective_moistening"
tendency_of_atmosphere_water_vapor_content_due_to_turbulence:kg m-2 s-1
tendency_of_water_vapor_content_of_atmosphere_layer_due_to_turbulence: kg m-2 s-1
Given that tendency_of_air_temperature_due_to_turbulence is already in the table I can see no reason why these names should not be included.
tendency_of_water_vapor_content_of_atmosphere_layer_due_to_stable_convection:kg m-2 s-1
I'm afraid I'm still not clear exactly what is meant by "stable_moistening" or "non_convective_moistening" - is this moistening due to advection or perhaps vertical advection in particular?
> 8. You define both these quantities as "energy resulting from shift in
> sigma-layer-definition with changing PS". What is the distinction between the
> two of them? Perhaps the second is in a layer?
>? atmosphere_phis:J m-2
>? phis:J m-2
> Is this a commonly used quantity that needs a standard name? It is obviously
> a model quantity, not an observational one, but it should have a name if it
> is being compared among models. However, we would need to give it a more
> self-explanatory name than "phi_s". Could you please describe it in some more
> detail?
> A: yes, atmosphere_phis is for whole atmosphere, phis is defined for layers.
> perhaps we can use
> energy_residual_due_to_shifting_definition_of_sigma_levels?
I propose the following names which, admittedly, are more verbose but I think they make the meaning clearer:
atmosphere_energy_residual_due_to_change_in_sigma_coordinate_with_surface_pressure: J m-2
energy_residual_of_atmosphere_layer_due_to_change_in_sigma_coordinate_with_surface_pressure: J m-2
> 9. In these quantities
> ? baseflow_amount:kg m-2
> ? runoff_excluding_baseflow_amount:kg m-2
> does "baseflow" mean the flow in rivers which comes from groundwater? You
> define baseflow as "surface runoff plus layer runoff minus baseflow", which
> seems contradictory, and the second quantity appears to exclude baseflow a
> second time. I haven't grasped the distinctions you are making - could you
> clarify, please?
> A: baseflow = groundwater flow
> ?runoff_excluding_baseflow = all runoff - baseflow (that means it is surface +
> subsurface except groundwater flow)
Please can you explain what is the difference between subsurface_runoff_amount (which is already in the table) and the groundwater flow which you describe as baseflow_amount. Is it that "subsurface" runoff isn't necessarily directed into rivers but baseflow is? (As I'm sure you can tell, this is not my area of expertise!)
> 10.The following come in pairs. What is the distinction between the two
> varieties?
> Is the shortwave absorption for upwelling or downwelling or both, the last
> being the difference between incoming and outgoing TOA SW? How do you
> define the longwave absorption, given that the atmosphere emits as well as > absorbing?
> By the energy released by convection do you mean the latent heat released > by condensation during convection (corresponding to large-scale)? ?In
> condensation do you include freezing?
>? rate_of_absorption_of_shortwave_energy:W m-2
>? atmosphere_rate_of_absorption_of_shortwave_energy:W m-2
>? rate_of_absorption_of_longwave_energy:W m-2
>? atmosphere_rate_of_absorption_of_longwave_energy:W m-2
>? rate_of_energy_released_by_deep_convection:W m-2
>? atmosphere_rate_of_energy_released_by_deep_convection:W m-2
>? rate_of_energy_released_by_shallow_convection:W m-2
>? atmosphere_rate_of_energy_released_by_shallow_convection:W m-2
>? rate_of_energy_released_by_large_scale_condensation:W m-2
>? atmosphere_rate_of_energy_released_by_large_scale_condensation:W m-2
> I am wondering whether we can use the word "power" in names for these
> quantities instead of "rate of X" where X is a kind of energy conversion.
> Power (strictly per unit area) is the correct physical term, of course,
> but not often used in meteorology.
> A: ?atmosphere_ is the value for the whole atmosphere, the other one is > layer defined
> by A.Ruane: This variables ?refers
> to net radiative effect. ?That means they refer to the rate of energy
> absorbed/emitted in the shortwave spectra, so a layer would have a
> positive value if it absorbed more shortwave radiation than it emitted.
> Therefore, none of the above options are correct, as it is both upward and
> downward shortwave energy. ?I would call it:
> rate_of_absorption_of_net_shortwave_energy: W m-2
> This is not the same as a TOA difference, particularly for those
> interested in specific atmospheric layers and the vertical column integral
> will differ from the TOA difference due to absorption of the land surface
> and any discrepancies in the model's radiation budget. ?The longwave is
> described in the same way:
> rate_of_absorption_of_net_longwave_energy: W m-2
> this may be confusing to some people, as there will often be negative
> net absorption (e.g. emission dominating absorption), but it is consistent
> with our wording. ?The clearest alternatives would be to call them:
> power_due_to_shortwave_energy: W m-2
> power_due_to_longwave_energy: W m-2
While I agree with Jonathan that power is a physically correct term, my personal opinion is that it is better to go with
atmosphere_rate_of_absorption_of_net_shortwave|longwave_energy: W m-2
rate_of_absorption_of_net_shortwave|longwave_energy_in_atmosphere_layer: W m-2
Regarding the convection and condensation names I echo Jonathan's questions as to the precise meaning.
11. I'm not clear which "energy" is referred to in
? energy_of_atmosphere_layer:J m-2
? horizontal_energy_transport_in_air:W m-2
? horizontal_atmosphere_energy_transport:W m-2
Is it the moist energy? (See 1st December posting.)
A: energy_of_atmosphere_layer:J m-2 should be dry_energy_content_of_atmosphere_layer:J m-2 (already in list)
horizontal_dry_energy_transport_in_air:W m-2 for layer-variable and
horizontal_atmosphere_dry_energy_transport:W m-2
For the horizontal transport names do you require separate eastward and northward components or will a single quantity suffice?
> 12. What energy is being referred to in these quantities?
> ? eastward_energy_flux_in_air; W m-1
> ? upward_energy_flux_in_air; W m-1
> ? northward_energy_flux_in_air; W m-1
> A: still open
>
> 13.We have atmosphere_energy_content in the table at present, but it is
> not really defined what it means. What do you mean by it in
>? tendency_of_atmosphere_energy_content:W m-2
> A: still open
I note that proposals 12 and 13 are still awaiting clarification.
> 14. For these
> ? horizontal_enthalpy_transport_in_air:W m-2
> ? horizontal_geopotential_energy_transport_in_air:W m-2
> ? horizontal_kinetic_energy_transport_in_air:W m-2
> we already have
> ? tendency_of_atmosphere_enthalpy_content_due_to_advection:W m-2
> ? tendency_of_atmosphere_potential_energy_content_due_to_advection:W m-2
> tendency_of_atmosphere_kinetic_energy_content_due_to_advection:W m-2
> Are they what you want? If so, what is the difference between these and
> the set
> ? horizontal_atmosphere_enthalpy_transport:W m-2
> ? horizontal_atmosphere_geopotential_energy_transport:W m-2
> ? horizontal_atmosphere_kinetic_energy_transport:W m-2
> You describe this set as "mass weighted" but I am unclear what distinction
> is being made, since both sets of quantities are in W m-2.
> A:
> instead of
> ? horizontal_atmosphere_enthalpy_transport:W m-2
> ? horizontal_atmosphere_geopotential_energy_transport:W m-2
> ? horizontal_atmosphere_kinetic_energy_transport:W m-2
> we can use
> ? tendency_of_atmosphere_enthalpy_content_due_to_advection:W m-2
> ? tendency_of_atmosphere_potential_energy_content_due_to_advection:W m-2
> ? tendency_of_atmosphere_kinetic_energy_content_due_to_advection:W m-2
> "mass weighted" is the way of calculation the vertical integral, it is the > normal way, so we don't have to mention it especially
> layer variables
> ? horizontal_enthalpy_transport_in_air:W m-2
> ? horizontal_geopotential_energy_transport_in_air:W m-2
> ? horizontal_kinetic_energy_transport_in_air:W m-2
> could be then
> ? tendency_of_enthalpy_content_due_to_advection_in_air:W m-2
> ? tendency_of_potential_energy_content_due_to_advection_in_air:W m-2
>? tendency_of_kinetic_energy_content_due_to_advection_in_air:W m-2
I would modify the names of the layer variables very slightly:
tendency_of_enthalpy_content_of_atmosphere_layer_due_to_advection:W m-2
tendency_of_potential_energy_content_of_atmosphere_layer_due_to_advection:W m-2
tendency_of_kinetic_energy_content_of_atmosphere_layer_due_to_advection:W m-2
otherwise these look fine to me.
> 15. two additional soil parameters concerning energy
> soil_thermal_capacity; J kg-1 K-1
> soil_thermal_conductivity; W m-1 K-1
These look fine.
> 16. one additional variable concerning water in soil
> volume_fraction_of_water_in_soil_at_critical_point
The name is fine. I had some difficulty finding a reference to temperature and pressure values giving a clear definition of the critical point of water. I eventually found
http://amsglossary.allenpress.com/glossary/search?id=critical-point1
- does this accord with the definition you are using. We should be clear about this.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 445858
Rutherford Appleton Laboratory Email: J.A.Pamment at rl.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
Received on Tue May 09 2006 - 05:04:21 BST
