Dear Alison These all look fine to me. Thanks very much
Jonathan ----- Forwarded message from Alison Pamment - UKRI STFC <[email protected]> ----- > Date: Fri, 29 Jun 2018 09:16:51 +0000 > From: Alison Pamment - UKRI STFC <[email protected]> > To: "[email protected]" <[email protected]> > Cc: Hyungjun Kim <[email protected]> > Subject: Re: [CF-metadata] Standard names for LS3MIP: 8 temporal changes + 1 > feature depth > > Dear Martin and Jonathan, > > Just picking up on this thread again - this is the 3rd (and final) group of > LS3MIP names remaining to be resolved. > > We have now received clarification of how various parts of the land liquid > water and ice budget are calculated, which I copy below so that we have a > record in this public discussion: > > 1) If we preferentially focus on mass balance, it would be straightforward > > to have: > > + soil moisture : total water in soil column > > + water table depth : depth of saturation > > + groundwater recharge : water flux at water table (which should be > > base flow if water table depth is lower than model soil depth) > > > > 2) In terrestrial hydrology, cold processes and associated storage are > > treated with liquid phase processes in general. > > Therefore, it would be more useful to have them in separated variables. > > > > 3) I mostly agree with you suggestion, but because of reason 2), it would > > be better to be defined as (although it is same to yours > > physically) summation of: > > + liquid phase surface water (water in rivers, wetlands, lakes, > > vegetation, reservoirs, canopy interception) > > + snow (&canopy interception), and ice, including grounded ice sheets > > and ice on lakes etc, but excluding ice shelves floating in sea water > > + liquid subsurface water > > + solid subsurface water > Many thanks to Hyungjun Kim for clarifying these important questions. > > I have used this explanation to finish writing definitions for these names. I > think most of the terms could now be accepted if you are happy with the > definitions. I have a question as to whether proposals 1.5 and 1.8 should > really include floating ice shelves, which seem to be explicitly excluded in > Hyungjun's text. > > > 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) > > From Hyungjun's description I have defined groundwater as 'Groundwater is > subsurface water below the depth of the water table.' This then gives us the > following definition for the proposed term: > '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. "Amount" means mass per unit area.' > > Okay? > > > 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)". > > For the river flow names, we decided that they include water in all phases > (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020241.html, proposal > 5), therefore I assume this one does too. Hence the definition would be: > '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.' > > Okay? > > > 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) > > The 'ice_and_snow_on_land' definition we agreed in > http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020250.html for the > nudging standard name and area_type seems a better fit to the proposed > quantity than land_ice because it includes river and lake ice, as well as > snow. > Hence I am changing my suggestion for this name to be: > change_over_time_in_amount_of_ice_and_snow_on_land (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. > "Amount" means mass per unit area. The phrase "ice_and_snow_on_land" means > ice in glaciers, ice caps, ice sheets & shelves, river and lake ice, any > other ice on a land surface, such as frozen flood water, and snow lying on > such ice or on the land surface.' > > This name and definition agree with the original proposal, but I note that > Hyungjun's text says 'excluding ice shelves floating in sea water' in the > second bullet of point (3). Are we sure that this CMIP dsn variable should > include ice shelves? > > > 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) > > Hyungjun's description of all land water components says: > > + liquid phase surface water (water in rivers, wetlands, lakes, > > vegetation, reservoirs, canopy interception) > > + snow (&canopy interception), and ice, including grounded ice sheets > > and ice on lakes etc, but excluding ice shelves floating in sea water > > + liquid subsurface water > > + solid subsurface water > > Hence, I would write the definition of land_water_amount (proposed for PMIP) > as: > ' "Amount" means mass per unit area. "Water" means water in all phases. The > quantity with standard name land_water_amount, often known as "Terrestrial > Water Storage", includes surface liquid water (water in rivers, wetlands, > lakes, reservoirs, rainfall intercepted by the canopy), surface ice and snow > (glaciers, ice caps, grounded ice sheets, river and lake ice and other > surface ice such as frozen flood water, snow lying on the surface and > intercepted by the canopy) and subsurface water (liquid and frozen soil > water, groundwater).' > > (This PMIP name can now also be accepted if you are happy with the > definition. N.B. It excludes floating ice shelves). > > Following on from this, the proposed name would be: > change_over_time_in_land_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. > "Amount" means mass per unit area. "Water" means water in all phases. The > quantity with standard name land_water_amount, often known as "Terrestrial > Water Storage", includes surface liquid water (water in rivers, wetlands, > lakes, reservoirs, rainfall intercepted by the canopy), surface ice and snow > (glaciers, ice caps, grounded ice sheets, river and lake ice and other > surface ice such as frozen flood water, snow lying on the surface and > intercepted by the canopy) and subsurface water (liquid and frozen soil > water, groundwater).' > > Okay? > > > 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 1.5 I am changing my suggestion to use the newly defined > 'ice_and_snow_on_land': > change_over_time_in_thermal_energy_content_of_ice_and_snow_on_land (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. > The surface called "surface" means the lower boundary of the atmosphere. > "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. The phrase "ice_and_snow_on_land" means ice in glaciers, ice > caps, ice sheets & shelves, river and lake ice, any other ice on a land > surface, such as frozen flood water, and snow lying on such ice or on the > land surface. > > Okay? As with 1.5, I'd like to double check that we should include floating > ice shelves, because this seems to differ from Hyungjun's description. > > > 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 > > For this one I previously suggested: > depth_at_shallowest_isotherm_defined_by_soil_temperature (m) > '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 or scalar > coordinate variable with standard name soil_temperature.' > > We already have soil_temperature as a standard name. Following discussion > (off list) with Martin, I think we also need to add a new area type of > 'unfrozen_soil' because this quantity should only be reported where the soil > at the surface is thawed. > > Okay? > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/Centre for Environmental Data Archival Email: > [email protected] > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > -----Original Message----- > From: CF-metadata <[email protected]> On Behalf Of Martin > Juckes - UKRI STFC > Sent: 17 May 2018 16:50 > To: [email protected] > Cc: Hyungjun Kim <[email protected]> > 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_an > + d_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 > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/Centre for Environmental Data Archival Email: > [email protected] > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
