Hello Beate,
Please see below for responses to those of your proposals currently outstanding.
>
> 5. stomatal_resistance - minimum and maximum are predefined theoretical
> values (dependent on vegetationtype). The actual values are calculated
> during simulation, depending on water supply and temperature, where
> minimum and maximum are fix for each vegetationtype. I send an email to
> get the exact formula from the modellers.
>
Thank you; I will wait for the additional information before commenting further on this.
>
>7. second part - still open
>
The proposals still open are:
tendency_of_atmosphere_water_vapor_content_due_to_non_convective_moistening: kg m-2 s-1
tendency_of_water_vapor_content_of_atmosphere_layer_due_to_non_convective_moistening: kg m-2 s-1.
I think that we still need clarification of which physical processes are included in non_convective_moistening. I am aware that condensation resulting from longwave cooling is one process, but please can you say which others are included?
>
>10. still open
>
There are four proposals relating to convection:
atmosphere_rate_of_latent_energy_release_due_to_deep_convection; W m-2
rate_of_latent_energy_release_in_atmosphere_layer_due_to_deep_convection; W m-2
atmosphere_rate_of_latent_energy_release_due_to_shallow_convection; W m-2
rate_of_latent_energy_release_in_atmosphere_layer_due_to_shallow_convection; W m-2
The names themselves are fine, but please can you confirm whether the latent heat release includes both condensation and freezing so that we can be clear in the definition.
There are two proposals relating to non-convective moistening:
rate_of_atmosphere_latent_energy_released_by_non_convective_moistening: W m-2
rate_of_latent_energy_in_atmosphere_layer_released_by_non_convective_moistening: W m-2
As with the proposals in (7) I would like to clarify which processes contribute to non-convective moistening.
>
>12. still open
>
There is a question about the units. I have reproduced my earlier comments below.
On 6 July 2006 Alison Pamment wrote:
> eastward_dry_energy_flux_in_air; W m-1
> upward_dry_energy_flux_in_air; W m-1
> northward_dry_energy_flux_in_air; W m-1
> The use of the term "flux" in a standard name implies "per unit area" but that would require > units of W m-2; the use of W m-1 would seem to imply a transport of energy across unit distance.
Please can you clarify what is needed here?
>
>16. volume_fraction_of_water_in_soil_at_critical_point
>references:
> http://www.crwr.utexas.edu/reports/1997/rpt97-1/SECT4.HTM
> http://www.life.uiuc.edu/plantbio/wimovac/newpage11.htm
>
The name is okay and the canonical unit is 1. Thank you for the references; based on them I have come up with the following definition:
The soil moisture critical point is one of the factors that determine the rate of evapotranspiration from vegetation. When soil moisture equals or exceeds the critical point evapotranspiration takes place at the potential rate and is controlled by the meteorological conditions. Potential evapotranspiration is the maximum rate of evapotranspiration from a uniformly vegetated area when there is an unlimited water supply. When the amount of soil moisture is between the critical point and the wilting point the rate of evapotranspiration decreases with decreasing soil moisture.
>
>17.+18. OK
>
Proposal 17 is:
friction_velocity; m s-1
I think that we are agreed on the name, but please note the following comment - on Monday 24th July 2006 Jonathan Gregory wrote:
>The term friction_velocity is fine, of course, but I think we ought to be specific about >which boundary layer we mean (atmosphere or ocean, and
> maybe a friction velocity might also be used in ocean bottom boundary
> layer - I don't know).
Please can you reply to Jonathan's point.
Proposal 18 is
greenness_index, Normalized Difference Vegetation Index (NDVI); 1.
Jonathan has suggested that we use normalized_difference_vegetation_index as the standard name. I agree. Are you happy with that idea?
>
> 19. specific_humidity_correction is fine (including the correct definition in the table)
>
Taking account of earlier comments from myself (13th July) and Jonathan (24th July) I would prefer that we include the word "model" in the standard name. Thus I propose:
correction_for_model_negative_specific_humidity; 1; Correction added to modelled negative specific humidities to set the value to zero. The modelled value can be recovered by subtracting the correction.
>
> 28. we have now
> atmosphere_downward_eastward_stress_due_to_diffusion; Pa
> atmosphere_downward_northward_stress_due_to_diffusion; Pa
> for the variables at levels I suppose:
> downward_eastward_stress_in_air_due_to_diffusion
> downward_northward_stress_in_air_due_to_diffusion
>
For these names Jonathan has pointed out that there is some ambiguity in the meaning:
> I wonder what this means, precisely. It could be the force (per unit area) experienced by a
> layer. In that case the name should indicate it applies to a layer, I suppose, and the
> quantity is the difference between the vertical flux of E|N momentum through the upper and
> lower surfaces. It wouldn't need to say upward or downward in that case, as it's a kind of
> divergence. On the other hand, it could mean the momentum flux through a level, and in that
> it does need to specify up|downward, as you say.
I had assumed the second interpretation, but please can you say which one is correct?
>
> 29. in the table we have tendency_of_air_temperature
> for 'vertically averaged tendency of temperature' I suppose:
> tendency_of_atmosphere_air_temperature (analogous to water_vapor-names)
>
The water vapor names, such as tendency_of_atmosphere_water_vapor_content, all refer to the
"atmosphere content" to indicate the vertical integral of the water vapor, whereas here you wish to define a mean quantity. I suggest we use:
atmosphere_mean_tendency_of_air_temperature
to indicate that the mean is over the entire column. I think it also makes better sense in English as "atmosphere_air_temperature" sounds a bit strange.
>
>30. in the table we already have
> product_of_eastward_wind_and_specific_humidity
> product_of_eastward_wind_and_air_temperature
> product_of_northward_wind_and_specific_humdity
> product_of_northward_wind_and_air_temperature
> there I'm in the need of the vertical integrals:
> what about
> atmosphere_product_of_... ?
>
On 21st September 2006 Jonathan Gregory wrote:
> Vertical integration changes the units and therefore the quantity. What
> are the units of the quantities you wish to name?
Please could you give some more details on how the quantities are calculated?
>
>31. tendency_of_atmosphere_water_vapor_content; kg m-2 s-1
>32. tendency_of_atmosphere_water_vapor_content_due_to_convection; kg m-2 s-1
>
Both these quantities were added to the table on 26th September. (They appear to be the same as proposals 21 and 22).
>
>33. analogous to no 20
>tendency_of_atmosphere_dry_energy_content; W m-2
>
This quantity was added to the table on 26th September (same as proposal 13).
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 Fri Oct 20 2006 - 22:00:26 BST
