Dear Martin and Jonathan,
Thank you for the proposal and discussion of these LS3MIP names. A few can be accepted straight away because they are based on existing names. I have questions about the definitions of some of them, mostly regarding the phase of water and inclusion of ice areas. Please see below for my detailed comments.
> 1.1 CMIP6 short name dcw. Change in Interception Storage
> The standard name "canopy_water_amount" exists.
>
> + Propose: change_over_time_in_canopy_water_amount (kg m-2)
'The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Canopy" means the plant or vegetation canopy. Canopy water is the water on the canopy. "Water" means water in all phases, including frozen, i.e. ice and snow. "Amount" means mass per unit area.'
The name and units look fine and I have constructed the definition from existing text. This name is accepted for publication in the standard name table and will be added in the next update.
> 1.2 CMIP6 short name dgw. Change in Groundwater
>We do not currently have any terms specifically for groundwater, so this concept needs to be defined: the following is proposed: "Groundwater is the subsurface water in the saturated zone."
>
> + propose: change_over_time_in_groundwater_amount (kg m-2)
We recently added the standard name "water_table_depth". Perhaps we could define "groundwater" in relation to that? Then we'd have something like:
'The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Water" means water in all phases. Groundwater is subsurface water below the depth of the water table, including soil moisture and underground aquifers. "Amount" means mass per unit area.'
Is it correct to say that this one includes "water in all phases" or would groundwater generally exist below the level at which freezing might occur? If it is always liquid, we should at least put that in the definition, if not in the name itself. This name is still under discussion.
> 1.3 CMIP6 short name drivw. Change in River Storage
> There is no existing term for the amount of water in rivers, though there are several for the rate of flow. Such terms as exist make no explicit reference to the definition of the what is meant by river water, so a clarification note is
> proposed.
>
> + Propose: change_over_time_in_river_water_amount (kg m-2)
> + "River water amount refers to the water in the fluvial system (stream and floodplain)".
Thank you for providing a definition for river water! If we remove the words 'water amount' this would be a useful sentence to add to all existing 'river' name definitions: ' "River" refers to water in the fluvial system (stream and floodplain).' Unless anyone objects, I will add this to the nine existing names at the next update.
The name and units look fine. I have constructed a definition based on the one provided and existing text:
'The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Water" means water in all phases. "River" refers to the water in the fluvial system (stream and floodplain). "Amount" means mass per unit area.'
Is it correct to say that this one includes "water in all phases", i.e. would it include ice floating on a river?
This name is still under discussion.
> 1.4 dslw Change in soil moisture
> Relates to changes in quantity mass_content_of_water_in_soil
>
> + Propose: change_over_time_in_mass_content_of_water_in_soil (kg m-2)
' The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Content" indicates a quantity per unit area. The mass content of water in soil refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. "Water" means water in all phases.'
The name and units look fine and I have constructed the definition from existing text. This name is accepted for publication in the standard name table and will be added in the next update.
> 1.5 CMIP6 short name dsn. Change in snow water equivalent (including snow and ice)
>
> The ice includes all the ice above ground, including glaciers, ice sheets and floating ice shelves.
>
> + Propose: change_over_time_in_surface_snow_and_ice_amount (kg m-2)
Looking at the list of ice areas that are included, this is consistent with our definition of 'land_ice', so I think we should put that in the name. Also, we have an existing name sea_ice_and_surface_snow_amount so I think it would be good to re-order the ice and snow terms in this proposal:
change_over_time_in_land_ice_and_surface_snow_amount (kg m-2)
'The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. The surface called "surface" means the lower boundary of the atmosphere. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock and also includes ice-shelves. "Amount" means mass per unit area.'
I am 99 per cent sure that the sea_ice_and_surface_snow name is really only referring to snow lying on the sea ice. Does the current proposal mean snow lying only on land_ice, or land and land_ice? I think we should add something to the definitions of both names to make the intentions clearer. I suppose we could even recommend that a mask be provided to show exactly which areas are included. What do you think?
This name is still under discussion.
> 1.6 CMIP6 short name dsw. Change in Surface Water Storage
> Surface water storage is interpreted as terrestrial water storage, which has a recently discussed name land_water_amount.
>
> + Propose: change_over_time_in_land_water_amount (kg m-2)
I think the name and units look fine. I note that we are still awaiting clarification of which ice areas are included in land_water (
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/060198.html). Once that question has been resolved I think it will be fine to also go ahead and accept this name.
This name is still under discussion.
> 1.7 CMIP6 short name dtes. Change in surface heat storage (excluding snow and ice)
> Includes soil layers+canopy+any other except snow/ice.
>
> + Propose: change_over_time_in_thermal_energy_content_of_vegetation_and_litter_and_soil (J m-2)
'The phrase "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Content" indicates a quantity per unit area. Thermal energy is the total vibrational energy, kinetic and potential, of all the molecules and atoms in a substance. "Vegetation" means any living plants e.g. trees, shrubs, grass. The term "plants" refers to the kingdom of plants in the modern classification which excludes fungi. Plants are autotrophs i.e. "producers" of biomass using carbon obtained from carbon dioxide. "Litter" is dead plant material in or above the soil. It is distinct from coarse wood debris. The precise distinction between "fine" and "coarse" is model dependent. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used.'
The name and units look fine and I have constructed the definition from existing text. This name is accepted for publication in the standard name table and will be added in the next update.
> 1.8 CMIP6 short name dtesn. Change in snow/ice cold content (CliC)
> "thermal_energy_content_of_surface_snow" exists, we can extend with "_and_ice".
>
> The ice includes all the ice above ground, including glaciers, ice sheets and floating ice shelves.
>
> + Propose: change_over_time_in_thermal_energy_content_of_surface_snow_and_ice (J m-2)
As for proposal 1.6 I think we should use 'land_ice' in the name and re-order it a little:
change_over_time_in_thermal_energy_content_of_land_ice_and_surface_snow (J m-2).
Also as for 1.6, does the 'surface_snow' mean only snow lying on land_ice, or snow lying on land and land_ice?
This name is still under discussion.
> 2. Feature depths
>
> 2.1 CMIP6 short name dmlt. Depth to soil thaw (CliC)
> Depth from surface to the zero degree isotherm. Above this isotherm T > 0o, and below this line T < 0o.
>
> When the surface temperature is above 0K and there is frozen soil at some point beneath the surface, thawed_soil_depth is the distance from the surface to the first 0K isotherm. When there is no thawed soil layer, the parameter
> should be reported as missing.
>
> + Proposed: thawed_soil_depth
This one has received some discussion, and the question has been how to make sure we are talking about the depth of the shallowest zero degree isotherm, when there could be more than one. This proposal reminds me of a couple of existing ocean names:
depth_at_shallowest_local_minimum_in_vertical_profile_of_mole_concentration_of_dissolved_molecular_oxygen_in_sea_water (m)
mole_concentration_of_dissolved_molecular_oxygen_in_sea_water_at_shallowest_local_minimum_in_vertical_profile (m)
I suggest that we combine this idea of 'shallowest' point in a profile with Jonathan's suggestion for using a coordinate variable. We could have something like:
depth_at_shallowest_isotherm_defined_by_soil_temperature
'Depth is the vertical distance below the surface. A soil temperature profile may go through one or more local minima or maxima. The "depth at shallowest isotherm" is the depth of the occurrence closest to the soil surface of an isotherm of the temperature specified by a coordinate variable with standard name soil_temperature.'
We already have soil_temperature as a standard name. What do you think?
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/Centre for Environmental Data Archival Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
-----Original Message-----
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> On Behalf Of Martin Juckes - UKRI STFC
Sent: 17 May 2018 16:50
To: cf-metadata at cgd.ucar.edu
Cc: Hyungjun Kim <hjkim at iis.u-tokyo.ac.jp>
Subject: [CF-metadata] Standard names for LS3MIP: 8 temporal changes + 1 feature depth
Dear All,
Following some discussion with Hyungjun, I'd like to propose the following new standard names to support the LS3MIP CMIP6 data request.
1. Changes over time
1.1 dcw Change in Interception Storage [kg m-2]
The standard name "canopy_water_amount" exists.
+ Propose: change_over_time_in_canopy_water_amount
1.2 dgw Change in Groundwater [kg m-2]
We do not currently have any terms specifically for groundwater, so this concept needs to be defined: the following is proposed: "Groundwater is the subsurface water in the saturated zone."
+ propose: change_over_time_in_groundwater_amount
1.3 drivw Change in River Storage [kg m-2]
There is no existing term for the amount of water in rivers, though there are several for the rate of flow. Such terms as exist make no explicit reference to the definition of the what is meant by river water, so a clarification note is proposed.
+ Propose: change_over_time_in_river_water_amount
+ "River water amount refers to the water in the fluvial system (stream and floodplain)".
1.4 dslw Change in soil moisture [kg m-2]
Relates to changes in quantity mass_content_of_water_in_soil
+ Propose: change_over_time_in_mass_content_of_water_in_soil
1.5 dsn Change in snow water equivalent (including snow and ice) [kg m-2]
The ice includes all the ice above ground, including glaciers, ice sheets and floating ice shelves.
+ Propose: change_over_time_in_surface_snow_and_ice_amount
1.6 dsw Change in Surface Water Storage [kg m-2]
Surface water storage is interpreted as terrestrial water storage, which has a recently discussed name land_water_amount.
+ Propose: change_over_time_in_land_water_amount
1.7 dtes Change in surface heat storage (excluding snow and ice) [J m-2]
Includes soil layers+canopy+any other except snow/ice.
+ Propose: change_over_time_in_thermal_energy_content_of_vegetation_and_litter_and_soil
1.8 dtesn Change in snow/ice cold content [J m-2] (CliC)
"thermal_energy_content_of_surface_snow" exists, we can extend with "_and_ice".
The ice includes all the ice above ground, including glaciers, ice sheets and floating ice shelves.
+ Propose: change_over_time_in_thermal_energy_content_of_surface_snow_and_ice
2. Feature depths
2.1 dmlt Depth to soil thaw [m] (CliC)
Depth from surface to the zero degree isotherm. Above this isotherm T > 0o, and below this line T < 0o.
When the surface temperature is above 0K and there is frozen soil at some point beneath the surface, thawed_soil_depth is the distance from the surface to the first 0K isotherm. When there is no thawed soil layer, the parameter should be reported as missing.
+ Proposed: thawed_soil_depth
regards,
Martin
_______________________________________________
CF-metadata mailing list
CF-metadata at cgd.ucar.edu
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Received on Thu May 24 2018 - 04:52:30 BST
