Proposals for CF

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"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. Conservative Temperature is defined as part of the Thermodynamic Equation of Seawater 2010 (TEOS-10) which was adopted in 2010 by the International Oceanographic Commission (IOC). Conservative Temperature is specific potential enthalpy (which has the standard name sea_water_specific_potential_enthalpy) divided by a fixed value of the specific heat capacity of sea water, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative Temperature is a more accurate measure of the "heat content" of sea water, by a factor of one hundred, than is potential temperature. Because of this, it can be regarded as being proportional to the heat content of sea water per unit mass. Reference: www.teos-10.org; McDougall, 2003 doi: 10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"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. "Horizontal mixing" means any horizontal transport other than by advection and parameterized eddy advection, usually represented as horizontal diffusion in ocean models. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

In thermodynamics and fluid mechanics, stagnation temperature is the temperature at a stagnation point in a fluid flow. At a stagnation point the speed of the fluid is zero and all of the kinetic energy has been converted to internal energy and is added to the local static enthalpy. In both compressible and incompressible fluid flow, the stagnation temperature is equal to the total temperature at all points on the streamline leading to the stagnation point. In aviation, stagnation temperature is known as total air temperature and is measured by a temperature probe mounted on the surface of the aircraft. The probe is designed to bring the air to rest relative to the aircraft. As the air is brought to rest, kinetic energy is converted to internal energy. The air is compressed and experiences an adiabatic increase in temperature. Therefore, total air temperature is higher than the static (or ambient) air temperature. Total air temperature is an essential input to an air data computer in order to enable computation of static air temperature and hence true airspeed. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The surface called "surface" means the lower boundary of the atmosphere.The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The surface called "surface" means the lower boundary of the atmosphere. The surface temperature is the temperature at the interface, not the bulk temperature of the medium above or below. Unless indicated in the cell_methods attribute, a quantity is assumed to apply to the whole area of each horizontal grid box. Previously, the qualifier where_type was used to specify that the quantity applies only to the part of the grid box of the named type. Names containing the where_type qualifier are deprecated and newly created data should use the cell_methods attribute to indicate the horizontal area to which the quantity applies. In order to convert the units correctly, it is essential to know whether a temperature is on-scale or a difference. Therefore this standard strongly recommends that any variable whose units involve a temperature unit should also have a units_metadata attribute to make the distinction. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

"product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "Northward" indicates a vector component which is positive when directed northward (negative southward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

"product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. A velocity is a vector quantity. "Upward" indicates a vector component which is positive when directed upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: kg degree_C m-2 (DKM2)

Updated term description

The phrase "integral_wrt_X_of_Y" means int Y dX. To specify the limits of the integral the data variable should have an axis for X and associated coordinate bounds. If no axis for X is associated with the data variable, or no coordinate bounds are specified, it is assumed that the integral is calculated over the entire vertical extent of the medium, e.g, if the medium is air the integral is assumed to be calculated over the full depth of the atmosphere. The phrase "wrt" means "with respect to". Depth is the vertical distance below the surface. The phrase "product_of_X_and_Y" means X*Y. Conservative Temperature is defined as part of the Thermodynamic Equation of Seawater 2010 (TEOS-10) which was adopted in 2010 by the International Oceanographic Commission (IOC). Conservative Temperature is specific potential enthalpy (which has the standard name sea_water_specific_potential_enthalpy) divided by a fixed value of the specific heat capacity of sea water, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative Temperature is a more accurate measure of the "heat content" of sea water, by a factor of one hundred, than is potential temperature. Because of this, it can be regarded as being proportional to the heat content of sea water per unit mass. Reference: www.teos-10.org; McDougall, 2003 doi: 10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2. Sea water density is the in-situ density (not the potential density). For Boussinesq models, density is the constant Boussinesq reference density, a quantity which has the standard name reference_sea_water_density_for_boussinesq_approximation. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: kg degree_C m-2 (DKM2)

Updated term description

The phrase "integral_wrt_X_of_Y" means int Y dX. To specify the limits of the integral the data variable should have an axis for X and associated coordinate bounds. If no axis for X is associated with the data variable, or no coordinate bounds are specified, it is assumed that the integral is calculated over the entire vertical extent of the medium, e.g, if the medium is air the integral is assumed to be calculated over the full depth of the atmosphere. The phrase "wrt" means "with respect to". The phrase "product_of_X_and_Y" means X*Y. Depth is the vertical distance below the surface. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. Sea water density is the in-situ density (not the potential density). For Boussinesq models, density is the constant Boussinesq reference density, a quantity which has the standard name reference_sea_water_density_for_boussinesq_approximation. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m (KMTX)

Updated term description

The phrase "integral_wrt_X_of_Y" means int Y dX. To specify the limits of the integral the data variable should have an axis for X and associated coordinate bounds. If no axis for X is associated with the data variable, or no coordinate bounds are specified, it is assumed that the integral is calculated over the entire vertical extent of the medium, e.g, if the medium is air the integral is assumed to be calculated over the full depth of the atmosphere. "wrt" means with respect to. Depth is the vertical distance below the surface. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

cloud_top refers to the top of the highest cloud. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s (KSXX)

Updated term description

The phrase "integral_wrt_X_of_Y" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The air temperature deficit is the air temperature threshold minus the air temperature, where only positive values are included in the integral. Its integral with respect to time is often called after its units of "degree-days". The air_temperature variable, which is the data variable of the integral should have a scalar coordinate variable or a size-one coordinate variable with the standard name of air_temperature_threshold, to indicate the threshold. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The "effective cloud top defined by infrared radiation" is (approximately) the geometric height above the surface that is one optical depth at infrared wavelengths (in the region of 11 micrometers) below the cloud top that would be detected by visible and lidar techniques. Reference: Minnis, P. et al 2011 CERES Edition-2 Cloud Property Retrievals Using TRMM VIRS and Terra and Aqua MODIS Data x2014; Part I: Algorithms IEEE Transactions on Geoscience and Remote Sensing, 49(11), 4374-4400. doi: http://dx.doi.org/10.1109/TGRS.2011.2144601. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s (KSXX)

Updated term description

The phrase "integral_wrt_X_of_Y" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The air temperature excess is the air temperature minus the air temperature threshold, where only positive values are included in the integral. Its integral with respect to time is often called after its units of "degree-days". The air_temperature variable, which is the data variable of the integral should have a scalar coordinate variable or a size-one coordinate variable with the standard name of air_temperature_threshold, to indicate the threshold. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. Air temperature excess and deficit are calculated relative to the air temperature threshold. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: on-scale", meaning that the temperature is relative to the origin of the scale indicated by the units, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The atmosphere_stability_showalter_index is an index used to determine convective and thunderstorm potential and is often referred to as simply the showalter index. The index is defined as the temperature difference between a parcel of air lifted from 850 to 500 hPa (wet adiabatically) and the ambient air temperature at 500 hPa. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: degree_C (UPAA)

Updated term description

The quantity with standard name sea_water_added_conservative_temperature is a passive tracer in an ocean model whose surface flux does not come from the atmosphere but is imposed externally upon the simulated climate system. The surface flux is expressed as a heat flux and converted to a passive tracer increment as if it were a heat flux being added to conservative temperature. The passive tracer is transported within the ocean as if it were conservative temperature. The passive tracer is zero in the control climate of the model. The passive tracer records added heat, as described for the CMIP6 FAFMIP experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas. Conservative Temperature is defined as part of the Thermodynamic Equation of Seawater 2010 (TEOS-10) which was adopted in 2010 by the International Oceanographic Commission (IOC). Conservative Temperature is specific potential enthalpy (which has the standard name sea_water_specific_potential_enthalpy) divided by a fixed value of the specific heat capacity of sea water, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative Temperature is a more accurate measure of the "heat content" of sea water, by a factor of one hundred, than is potential temperature. Because of this, it can be regarded as being proportional to the heat content of sea water per unit mass. Reference: www.teos-10.org; McDougall, 2003 doi: 10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: degree_C (UPAA)

Updated term description

The quantity with standard name sea_water_added_potential_temperature is a passive tracer in an ocean model whose surface flux does not come from the atmosphere but is imposed externally upon the simulated climate system. The surface flux is expressed as a heat flux and converted to a passive tracer increment as if it were a heat flux being added to potential temperature. The passive tracer is transported within the ocean as if it were potential temperature. The passive tracer is zero in the control climate of the model. The passive tracer records added heat, as described for the CMIP6 FAFMIP experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: degree_C (UPAA)

Updated term description

The quantity with standard name sea_water_redistributed_conservative_temperature is a passive tracer in an ocean model which is subject to an externally imposed perturbative surface heat flux. The passive tracer is initialised to the conservative temperature in the control climate before the perturbation is imposed. Its surface flux is the heat flux from the atmosphere, not including the imposed perturbation, and is converted to a passive tracer increment as if it were being added to conservative temperature. The passive tracer is transported within the ocean as if it were conservative temperature. The passive tracer records redistributed heat, as described for the CMIP6 FAFMIP experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas. Conservative Temperature is defined as part of the Thermodynamic Equation of Seawater 2010 (TEOS-10) which was adopted in 2010 by the International Oceanographic Commission (IOC). Conservative Temperature is specific potential enthalpy (which has the standard name sea_water_specific_potential_enthalpy) divided by a fixed value of the specific heat capacity of sea water, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative Temperature is a more accurate measure of the "heat content" of sea water, by a factor of one hundred, than is potential temperature. Because of this, it can be regarded as being proportional to the heat content of sea water per unit mass. Reference: www.teos-10.org; McDougall, 2003 doi: 10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: degree_C (UPAA)

Updated term description

The quantity with standard name sea_water_redistributed_potential_temperature is a passive tracer in an ocean model which is subject to an externally imposed perturbative surface heat flux. The passive tracer is initialised to the potential temperature in the control climate before the perturbation is imposed. Its surface flux is the heat flux from the atmosphere, not including the imposed perturbation, and is converted to a passive tracer increment as if it were being added to potential temperature. The passive tracer is transported within the ocean as if it were potential temperature. The passive tracer records redistributed heat, as described for the CMIP6 FAFMIP experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: degree_C (UPAA)

Updated term description

Universal Thermal Comfort Index (UTCI) is an equivalent temperature of the actual thermal condition. Reference: utci.org. It is the air temperature of a reference condition causing the same dynamic physiological response in a human body considering its energy budget, physiology and clothing adaptation. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"Canopy temperature" is the bulk temperature of the canopy, not the surface (skin) temperature. "Canopy" means the vegetative covering over a surface. The canopy is often considered to be the outer surfaces of the vegetation. Plant height and the distribution, orientation and shape of plant leaves within a canopy influence the atmospheric environment and many plant processes within the canopy. Reference: AMS Glossary http://glossary.ametsoc.org/wiki/Canopy. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"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.Sea water temperature is the in situ temperature of the sea water. To specify the depth at which the temperature applies use a vertical coordinate variable or scalar coordinate variable. There are standard names for sea_surface_temperature, sea_surface_skin_temperature, sea_surface_subskin_temperature and sea_surface_foundation_temperature which can be used to describe data located at the specified surfaces. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Dew point depression is also called dew point deficit. It is the amount by which the air temperature exceeds its dew point temperature. Dew point temperature is the temperature at which a parcel of air reaches saturation upon being cooled at constant pressure and specific humidity. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Dew point temperature is the temperature at which a parcel of air reaches saturation upon being cooled at constant pressure and specific humidity. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea surface temperature is usually abbreviated as "SST". It is the temperature of sea water near the surface (including the part under sea-ice, if any), not the skin or interface temperature, whose standard names are sea_surface_skin_temperature and surface_temperature, respectively. For the temperature of sea water at a particular depth or layer, a data variable of "sea_water_temperature" with a vertical coordinate axis should be used. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The dynamical tropopause used in interpreting the dynamics of the upper troposphere and lower stratosphere. There are various definitions of dynamical tropopause in the scientific literature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. "tendency_of_X" means derivative of X with respect to time. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name heat_index_of_air_temperature is the perceived air temperature when relative humidity is taken into consideration (which makes it feel hotter than the actual air temperature). Heat index is only defined when the ambient air temperature is at or above 299.817 K. References: https://www.weather.gov/safety/heat-index; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/_0-0-12. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock and also includes ice-shelves. The standard name land_ice_basal_temperature means the temperature of the land ice at its lower boundary. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock and also includes ice-shelves. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. "longwave" means longwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. The standard name sea_ice_basal_temperature means the temperature of the sea ice at its lower boundary. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The surface temperature is the (skin) temperature at the interface, not the bulk temperature of the medium above or below. "Sea ice surface temperature" is the temperature that exists at the interface of sea ice and an overlying medium which may be air or snow. In areas of snow covered sea ice, sea_ice_surface_temperature is not the same as the quantity with standard name surface_temperature. "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea ice temperature is the bulk temperature of the sea ice, not the surface (skin) temperature. "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The sea surface skin temperature is the temperature measured by an infrared radiometer typically operating at wavelengths in the range 3.7 - 12 micrometers. It represents the temperature within the conductive diffusion-dominated sub-layer at a depth of approximately 10 - 20 micrometers below the air-sea interface. Measurements of this quantity are subject to a large potential diurnal cycle including cool skin layer effects (especially at night under clear skies and low wind speed conditions) and warm layer effects in the daytime. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The sea surface subskin temperature is the temperature at the base of the conductive laminar sub-layer of the ocean surface, that is, at a depth of approximately 1 - 1.5 millimeters below the air-sea interface. For practical purposes, this quantity can be well approximated to the measurement of surface temperature by a microwave radiometer operating in the 6 - 11 gigahertz frequency range, but the relationship is neither direct nor invariant to changing physical conditions or to the specific geometry of the microwave measurements. Measurements of this quantity are subject to a large potential diurnal cycle due to thermal stratification of the upper ocean layer in low wind speed high solar irradiance conditions. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "tendency_of_X" means derivative of X with respect to time. "shortwave" means shortwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. The term "shortwave" means shortwave radiation. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. "Ambient aerosol particles" are aerosol particles that have taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the particles. To specify the relative humidity and temperature at which the quantity described by the standard name applies, provide scalar coordinate variables with standard names of "relative_humidity" and "air_temperature". Volcanic aerosols include both volcanic ash and secondary products such as sulphate aerosols formed from gaseous emissions of volcanic eruptions. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). "Precipitation" in the earth's atmosphere means precipitation of water in all phases. A variable with the standard name tendency_of_air_temperature_due_to_stratiform_cloud_and_precipitation should contain net latent heating effects of all processes which convert stratiform clouds and precipitation between water vapor, liquid or ice phases. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). "Precipitation" in the earth's atmosphere means precipitation of water in all phases. "Boundary layer mixing" means turbulent motions that transport heat, water, momentum and chemical constituents within the atmospheric boundary layer and affect exchanges between the surface and the atmosphere. The atmospheric boundary layer is typically characterised by a well-mixed sub-cloud layer of order 500 metres, and by a more extended conditionally unstable layer with boundary-layer clouds up to 2 km. (Reference: IPCC Third Assessment Report, Working Group 1: The Scientific Basis, 7.2.2.3, https://archive.ipcc.ch/ipccreports/tar/wg1/273.htm). It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea water temperature is the in situ temperature of the sea water. To specify the depth at which the temperature applies use a vertical coordinate variable or scalar coordinate variable. There are standard names for sea_surface_temperature, sea_surface_skin_temperature, sea_surface_subskin_temperature and sea_surface_foundation_temperature which can be used to describe data located at the specified surfaces. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea water temperature is the in situ temperature of the sea water. The temperature at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model and within the benthic boundary layer for measurements. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"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. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The quantity with standard name temperature_at_base_of_ice_sheet_model is the lower boundary temperature that is used to force ice sheet models. Beneath ice shelves it is the temperature at the ice-ocean interface. Beneath grounded ice, it is the temperature at the ice-bedrock interface. In all instances the temperature is that of the interface itself and not that of the medium above or below the interface. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The quantity with standard name temperature_at_top_of_ice_sheet_model is the upper boundary temperature that is used to force ice sheet models. It is the temperature at the interface between the ice sheet and the overlying medium which may be snow or the atmosphere. In all instances the temperature is that of the interface itself and not that of the medium above or below the interface. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from a starting air pressure to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the starting air pressure to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air. Coordinate variables of original_air_pressure_of_lifted_parcel and final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressures at which the parcel lifting starts (starting air pressure) and the temperature difference is calculated at (finishing air pressure), respectively. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from the surface to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the surface to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The term "surface" means the lower boundary of the atmosphere. A coordinate variable of final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressure that the temperature difference is calculated at. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"Temperature in surface snow" is the bulk temperature of the snow, not the surface (skin) temperature. Surface snow refers to the snow on the solid ground or on surface ice cover, but excludes, for example, falling snowflakes and snow on plants. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

toa_brightness_temperature_bias_at_standard_scene_due_to_intercalibration is the difference between top-of-atmosphere (TOA) brightness temperatureof the reference sensor and TOA brightness temperature of themonitored sensor. This TOA brightness temperature difference is a measure of the calibration difference between the monitored and reference sensors. The standard scene is a target area with typical Earth surface and atmospheric conditions that is accepted as a reference. Brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area at a given wavenumber. TOA brightness temperature of the standard scene is calculated using a radiative transfer simulation for a given viewing geometry. The resultant top-of-atmosphere spectral radiance is then integrated with each sensor's spectral response function and converted to equivalent brightness temperature. 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. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"toa" means top of atmosphere. The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area at a given wavenumber. The standard scene is a target area with typical Earth surface and atmospheric conditions that is accepted as a reference. The toa radiance of the standard scene is calculated using a radiative transfer model for a given viewing geometry. The resultant toa spectral radiance is then integrated with a sensor's spectral response function and converted to equivalent brightness temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The quantity with standard name tropical_cyclone_eye_brightness_temperature is the warmest brightness temperature value in the eye region of a tropical cyclone (0 - 24 km from the storm center) derived using the Advanced Dvorak Technique, based on satellite observations. Reference: Olander, T. L., & Velden, C. S., The Advanced Dvorak Technique: Continued Development of an Objective Scheme to Estimate Tropical Cyclone Intensity Using Geostationary Infrared Satellite Imagery (2007). American Meteorological Society Weather and Forecasting, 22, 287-298. The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The virtual temperature of air is the temperature at which the dry air constituent of a parcel of moist air would have the same density as the moist air at the same pressure. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Wet bulb potential temperature is the temperature a parcel of air would have if moved dry adiabatically until it reaches saturation and thereafter moist adiabatically to sea level pressure. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m-1 (DKPM)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. A lapse rate is the negative derivative of a quantity with respect to increasing height above the surface, or the (positive) derivative with respect to increasing depth. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

Covariance refers to the sample covariance rather than the population covariance. The quantity with standard name covariance_over_longitude_of_northward_wind_and_air_temperature is the covariance of the deviations of meridional air velocity and air temperature about their respective zonal mean values. The data variable must be accompanied by a vertical coordinate variable or scalar coordinate variable and is calculated on an isosurface of that vertical coordinate. "Northward" indicates a vector component which is positive when directed northward (negative southward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name "upward_air_velocity"). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

"product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

"product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K m s-1 (KMTS)

Updated term description

"product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K2 (KLSQ)

Updated term description

"square_of_X" means X*X. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. "toa" means top of atmosphere. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. "shortwave" means shortwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. The term "longwave" means longwave radiation. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. "Ambient_aerosol" means that the aerosol is measured or modelled at the ambient state of pressure, temperature and relative humidity that exists in its immediate environment. "Ambient aerosol particles" are aerosol particles that have taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the particles. To specify the relative humidity and temperature at which the quantity described by the standard name applies, provide scalar coordinate variables with standard names of "relative_humidity" and "air_temperature". Volcanic aerosols include both volcanic ash and secondary products such as sulphate aerosols formed from gaseous emissions of volcanic eruptions. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. "tendency_of_X" means derivative of X with respect to time. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The temperature at any given depth (or in a layer) below the surface of the ground, excluding surficial snow and ice (but not permafrost or soil). For temperatures in surface lying snow and ice, the more specific standard names temperature_in_surface_snow and land_ice_temperature should be used. For temperatures measured or modelled specifically for the soil layer (the near-surface layer where plants sink their roots) the standard name soil_temperature should be used. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "tendency_of_X" means derivative of X with respect to time. "longwave" means longwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The atmosphere_stability_total_totals_index indicates thelikelihood of severe convection and is often referred to as simply thetotal totals index. The index is derived from the difference in airtemperature between 850 and 500 hPa (the vertical totals) and thedifference between the dew point temperature at 850 hPa and the airtemperature at 500 hPa (the cross totals). The vertical totals and crosstotals are summed to obtain the index. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units)..

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"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. "Vertical mixing" means any vertical transport other than by advection and parameterized eddy advection, represented by a combination of vertical diffusion, turbulent mixing and convection in ocean models. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. "Boundary layer mixing" means turbulent motions that transport heat, water, momentum and chemical constituents within the atmospheric boundary layer and affect exchanges between the surface and the atmosphere. The atmospheric boundary layer is typically characterised by a well-mixed sub-cloud layer of order 500 metres, and by a more extended conditionally unstable layer with boundary-layer clouds up to 2 km. (Reference: IPCC Third Assessment Report, Working Group 1: The Scientific Basis, 7.2.2.3, https://archive.ipcc.ch/ipccreports/tar/wg1/273.htm). It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Conservative Temperature is defined as part of the Thermodynamic Equation of Seawater 2010 (TEOS-10) which was adopted in 2010 by the International Oceanographic Commission (IOC). Conservative Temperature is specific potential enthalpy (which has the standard name sea_water_specific_potential_enthalpy) divided by a fixed value of the specific heat capacity of sea water, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative Temperature is a more accurate measure of the "heat content" of sea water, by a factor of one hundred, than is potential temperature. Because of this, it can be regarded as being proportional to the heat content of sea water per unit mass. Reference: www.teos-10.org; McDougall, 2003 doi: 10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: W m-1 K-1 (WAPK)

Updated term description

Thermal conductivity is the constant k in the formula q = -k grad T where q is the heat transfer per unit time per unit area of a surface normal to the direction of transfer and grad T is the temperature gradient. Thermal conductivity is a property of the material. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The sea surface foundation temperature is the water temperature that is not influenced by a thermally stratified layer of diurnal temperature variability (either by daytime warming or nocturnal cooling). The foundation temperature is named to indicate that it is the temperature from which the growth of the diurnal thermocline develops each day, noting that on some occasions with a deep mixed layer there is no clear foundation temperature in the surface layer. In general, sea surface foundation temperature will be similar to a night time minimum or pre-dawn value at depths of between approximately 1 and 5 meters. In the absence of any diurnal signal, the foundation temperature is considered equivalent to the quantity with standard name sea_surface_subskin_temperature. The sea surface foundation temperature defines a level in the upper water column that varies in depth, space, and time depending on the local balance between thermal stratification and turbulent energy and is expected to change slowly over the course of a day. If possible, a data variable with the standard name sea_surface_foundation_temperature should be used with a scalar vertical coordinate variable to specify the depth of the foundation level. Sea surface foundation temperature is measured at the base of the diurnal thermocline or as close to the water surface as possible in the absence of thermal stratification. Only in situ contact thermometry is able to measure the sea surface foundation temperature. Analysis procedures must be used to estimate sea surface foundation temperature value from radiometric satellite measurements of the quantities with standard names sea_surface_skin_temperature and sea_surface_subskin_temperature. Sea surface foundation temperature provides a connection with the historical concept of a "bulk" sea surface temperature considered representative of the oceanic mixed layer temperature that is typically represented by any sea temperature measurement within the upper ocean over a depth range of 1 to approximately 20 meters. The general term, "bulk" sea surface temperature, has the standard name sea_surface_temperature with no associated vertical coordinate axis. Sea surface foundation temperature provides a more precise, well defined quantity than "bulk" sea surface temperature and, consequently, is more representative of the mixed layer temperature. The temperature of sea water at a particular depth (other than the foundation level) should be reported using the standard name sea_water_temperature and, wherever possible, supplying a vertical coordinate axis or scalar coordinate variable. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. The potential temperature at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model and within the benthic boundary layer for measurements. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

"product_of_X_and_Y" means X*Y. "specific" means per unit mass. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. Specific humidity is the mass fraction of water vapor in (moist) air. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K2 (KLSQ)

Updated term description

Sea surface temperature is usually abbreviated as "SST". It is the temperature of sea water near the surface (including the part under sea-ice, if any), and not the skin temperature, whose standard name is surface_temperature. For the temperature of sea water at a particular depth or layer, a data variable of sea_water_temperature with a vertical coordinate axis should be used. "square_of_X" means X*X. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: J kg-1 K-1 (JKGK)

Updated term description

The specific heat capacity of sea water, Cp(ocean), is used in ocean models to convert between model prognostic temperature (potential or conservative temperature) and model heat content. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"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. Parameterized eddy advection in an ocean model means the part due to a scheme representing parameterized eddy-induced advective effects not included in the resolved model velocity field. Parameterized eddy advection can be represented on various spatial scales and there are standard names for parameterized_mesoscale_eddy_advection and parameterized_submesoscale_eddy_advection which both contribute to the total parameterized eddy advection. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea water temperature is the in situ temperature of the sea water. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). "Precipitation" in the earth's atmosphere means precipitation of water in all phases. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: J kg-1 K-1 (JKGK)

Updated term description

Thermal capacity, or heat capacity, is the amount of heat energy required to increase the temperature of 1 kg of material by 1 K. It is a property of the material. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The overall temperature of a fire area due to contributions from smoldering and flaming biomass. A data variable containing the area affected by fire should be given the standard name fire_area. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Sea surface temperature is usually abbreviated as "SST". It is the temperature of sea water near the surface (including the part under sea-ice, if any). More specific terms, namely sea_surface_skin_temperature, sea_surface_subskin_temperature, and surface_temperature are available for the skin, subskin, and interface temperature. respectively. For the temperature of sea water at a particular depth or layer, a data variable of sea_water_temperature with a vertical coordinate axis should be used. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name wind_chill_of_air_temperature is the perceived air temperature when wind is factored in with the ambient air temperature (which makes it feel colder than the actual air temperature). Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. Wind chill temperature is only defined for ambient temperatures at or below 283.1 K and wind speeds above 1.34 m s-1. References: https://www.weather.gov/safety/cold-wind-chill-chart; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/0-0-13. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K Pa s-1 (KPAS)

Updated term description

The phrase "product_of_X_and_Y" means X*Y. The phrase "tendency_of_X" means derivative of X with respect to time. The Lagrangian tendency of a quantity is its rate of change following the motion of the fluid, also called the "material derivative" or "convective derivative". The Lagrangian tendency of air pressure, often called "omega", plays the role of the upward component of air velocity when air pressure is being used as the vertical coordinate. If the vertical air velocity is upwards, it is negative when expressed as a tendency of air pressure; downwards is positive. Air pressure is the force per unit area which would be exerted when the moving gas molecules of which the air is composed strike a theoretical surface of any orientation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. "Orographic gravity waves" refer to gravity waves which are generated by flow over orography. The dissipation of gravity waves generates heating through an eddy heat flux convergence and through a viscous stress term. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

"tendency_of_X" means derivative of X with respect to time. Sea water temperature is the in situ temperature of the sea water. For observed data, depending on the period during which the observation was made, the measured in situ temperature was recorded against standard "scales". These historical scales include the International Practical Temperature Scale of 1948 (IPTS-48; 1948-1967), the International Practical Temperature Scale of 1968 (IPTS-68, Barber, 1969; 1968-1989) and the International Temperature Scale of 1990 (ITS-90, Saunders 1990; 1990 onwards). Conversion of data between these scales follows t68 = t48 - (4.4 x 10e-6) * t48(100 - t - 48); t90 = 0.99976 * t68. Observations made prior to 1948 (IPTS-48) have not been documented and therefore a conversion cannot be certain. Differences between t90 and t68 can be up to 0.01 at temperatures of 40 C and above; differences of 0.002-0.007 occur across the standard range of ocean temperatures (-10 - 30 C). The International Equation of State of Seawater 1980 (EOS-80, UNESCO, 1981) and the Practical Salinity Scale (PSS-78) were both based on IPTS-68, while the Thermodynamic Equation of Seawater 2010 (TEOS-10) is based on ITS-90. References: Barber, 1969, doi: 10.1088/0026-1394/5/2/001; UNESCO, 1981; Saunders, 1990, WOCE Newsletter, 10, September 1990. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Soil temperature is the bulk temperature of the soil, not the surface (skin) temperature. "Soil" means the near-surface layer where plants sink their roots. For subsurface temperatures that extend beneath the soil layer or in areas where there is no surface soil layer, the standard name temperature_in_ground should be used. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. "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. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

cloud_top refers to the top of the highest cloud. brightness_temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. A coordinate variable of radiation_wavelength, sensor_band_central_radiation_wavelength, or radiation_frequency may be specified to indicate that the brightness temperature applies at specific wavelengths or frequencies. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K s-1 (KPRS)

Updated term description

The phrase "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 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. "Nonorographic" gravity waves refer to gravity waves which are not generated by flow over orography. The dissipation of gravity waves generates heating through an eddy heat flux convergence and through a viscous stress term. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory & Lars Barring

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Classification of existing standard names for units_metadata

Units: K (UPKA)

Updated term description

The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "toa" means top of atmosphere. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory

Proposed Date: Jan. 10, 2024

Comments: #270

CF mailing list link: Modify description of atmosphere_stability_k_index

Units: K (UPKA)

Updated term description

The atmosphere_stability_k_index is an index that indicates the potential of severe convection and is often referred to as simply the k index. The index is calculated as A + B - C, where A is the difference in air temperature between 850 and 500 hPa, B is the dew point temperature at 850 hPa, and C is the dew point depression (i.e. the amount by which the air temperature exceeds its dew point temperature) at 700 hPa. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).

Proposer: Jonathan Gregory

Proposed Date: March 9, 2023

Comments:

CF mailing list link: Standard names: Virtual potential temperature

Units: K (UPKA)

The virtual temperature of air is the temperature at which the dry air constituent of a parcel of moist air would have the same density as the moist air at the same pressure.