Update for CF Version:48

northward_ocean_heat_transport_due_to_parameterized_submesoscale_eddy_advection

Unit: W
Unit ref: WATT
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection.

ocean_meridional_overturning_mass_streamfunction_due_to_parameterized_mesoscale_eddy_advection

Unit: kg s-1
Unit ref: KGPS
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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

northward_ocean_heat_transport_due_to_parameterized_mesoscale_eddy_diffusion

Unit: W
Unit ref: WATT
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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 mesoscale eddy diffusive processes include diffusion along neutral directions in the interior of the ocean and horizontal diffusion in the surface boundary layer. The processes occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_residual_mean_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. 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 phrase "residual_mean_advection" refers to the sum of the model's resolved advective transport plus any parameterized advective transport. Parameterized advective transport includes processes such as parameterized mesoscale and submesoscale transport, as well as any other advectively parameterized transport. When the parameterized advective transport is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic, since the convergence of skew-fluxes are identical (in the continuous formulation) to the convergence of advective fluxes.

sea_water_salinity_at_sea_floor

Unit: 1e-3
Unit ref: UUUU
The salinity at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. Sea water salinity is the salt concentration of sea water, often on the Practical Salinity Scale of 1978. However, the unqualified term 'salinity' is generic and does not necessarily imply any particular method of calculation. The units of salinity are dimensionless and the units attribute should normally be given as 1e-3 or 0.001 i.e. parts per thousand. There are standard names for the more precisely defined salinity quantities sea_water_knudsen_salinity, S_K (used for salinity observations between 1901 and 1966), sea_water_cox_salinity, S_C (used for salinity observations between 1967 and 1977), sea_water_practical_salinity, S_P (used for salinity observations from 1978 to the present day), sea_water_absolute_salinity, S_A, sea_water_preformed_salinity, S_*, and sea_water_reference_salinity. Practical Salinity is reported on the Practical Salinity Scale of 1978 (PSS-78), and is usually based on the electrical conductivity of sea water in observations since the 1960s. Conversion of data between the observed scales follows S_P = (S_K - 0.03) * (1.80655 / 1.805) and S_P = S_C, however the accuracy of the latter is dependent on whether chlorinity or conductivity was used to determine the S_C value, with this inconsistency driving the development of PSS-78. The more precise standard names should be used where appropriate for both modelled and observed salinities. In particular, the use of sea_water_salinity to describe salinity observations made from 1978 onwards is now deprecated in favor of the term sea_water_practical_salinity which is the salinity quantity stored by national data centers for post-1978 observations. The only exception to this is where the observed salinities are definitely known not to be recorded on the Practical Salinity Scale. Practical salinity units are dimensionless. The unit "parts per thousand" was used for sea_water_knudsen_salinity and sea_water_cox_salinity.

ocean_tracer_diffusivity_due_to_parameterized_mesoscale_eddy_advection

Unit: m2 s-1
Unit ref: SQMS
Diffusivity is also sometimes known as the coefficient of diffusion. Diffusion occurs as a result of a gradient in the spatial distribution of mass concentration, temperature or momentum. The diffusivity may be very different in the vertical and horizontal directions. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_residual_mean_advection

Unit: W m-2
Unit ref: UFAA
"tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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 phrase "residual_mean_advection" refers to the sum of the model's resolved advective transport plus any parameterized advective transport. Parameterized advective transport includes processes such as parameterized mesoscale and submesoscale transport, as well as any other advectively parameterized transport. When the parameterized advective transport is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic, since the convergence of skew-fluxes are identical (in the continuous formulation) to the convergence of advective fluxes.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_parameterized_eddy_dianeutral_mixing

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. 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. "Eddy dianeutral mixing" means dianeutral mixing, i.e. mixing across neutral directions caused by the unresolved turbulent motion of eddies of all types (e.g., breaking gravity waves, boundary layer turbulence, etc.).

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_parameterized_eddy_dianeutral_mixing

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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. "Eddy dianeutral mixing" means dianeutral mixing, i.e. mixing across neutral directions caused by the unresolved turbulent motion of eddies of all types (e.g., breaking gravity waves, boundary layer turbulence, etc.).

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content

Unit: W m-2
Unit ref: UFAA
"Content" indicates a quantity per unit area. The phrase "tendency_of_X" means derivative of X with respect to time. This tendency encompasses all processes that impact on the time changes for the heat content within a grid cell. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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.

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_parameterized_mesoscale_eddy_diffusion

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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 mesoscale eddy diffusive processes include diffusion along neutral directions in the interior of the ocean and horizontal diffusion in the surface boundary layer. The processes occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell.

ocean_y_overturning_mass_streamfunction_due_to_parameterized_mesoscale_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

ocean_y_overturning_mass_streamfunction_due_to_parameterized_submesoscale_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_residual_mean_advection

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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 phrase "residual_mean_advection" refers to the sum of the model's resolved advective transport plus any parameterized advective transport. Parameterized advective transport includes processes such as parameterized mesoscale and submesoscale transport, as well as any other advectively parameterized transport. When the parameterized advective transport is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic, since the convergence of skew-fluxes are identical (in the continuous formulation) to the convergence of advective fluxes.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_parameterized_submesoscale_eddy_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. 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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_parameterized_submesoscale_eddy_advection

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

ocean_meridional_overturning_mass_streamfunction_due_to_parameterized_submesoscale_eddy_advection

Unit: kg s-1
Unit ref: KGPS
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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_parameterized_mesoscale_eddy_advection

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_parameterized_mesoscale_eddy_diffusion

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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 mesoscale eddy diffusive processes include diffusion along neutral directions in the interior of the ocean and horizontal diffusion in the surface boundary layer. The processes occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks.

tendency_of_sea_water_salinity_expressed_as_salt_content

Unit: kg m-2 s-1
Unit ref: KSP2
"Content" indicates a quantity per unit area. "tendency_of_X" means derivative of X with respect to time. This tendency encompasses all processes that impact on the time changes for the salt content within a grid cell.

x_wind_gust

Unit: m s-1
Unit ref: UVAA
"x" indicates a vector component along the grid x-axis, positive with increasing x. 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.) A gust is a sudden brief period of high wind speed. In an observed timeseries of wind speed, the gust wind speed can be indicated by a cell_methods of maximum for the time-interval. In an atmospheric model which has a parametrised calculation of gustiness, the gust wind speed may be separately diagnosed from the wind speed.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_parameterized_mesoscale_eddy_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_parameterized_eddy_dianeutral_mixing

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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. "Eddy dianeutral mixing" means dianeutral mixing, i.e. mixing across neutral directions caused by the unresolved turbulent motion of eddies of all types (e.g., breaking gravity waves, boundary layer turbulence, etc.).

volume_beam_attenuation_coefficient_of_radiative_flux_in_sea_water_corrected_for_pure_water_attenuance

Unit: m-1
Unit ref: UPRM
Radiative flux is the sum of shortwave and longwave radiative fluxes. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The volume scattering/absorption/attenuation coefficient is the fractional change of radiative flux per unit path length due to the stated process. The scattering/absorption/attenuation coefficient is assumed to be an integral over all wavelengths, unless a coordinate of radiation_wavelength is included to specify the wavelength. Attenuation is the sum of absorption and scattering. Attenuation is sometimes called "extinction". Beam attenuation refers to the decrease of radiative flux along the direction of the incident path. It is distinguished from attenuation of the downwelling component of radiative flux from any incident direction, also called "diffuse" attenuation. The phrase "corrected for pure water attenuance" means the attenuation coefficient has been adjusted/calibrated to remove the influence of absorption/scattering by the water itself. Coefficients with canonical units of m2 s-1 i.e. multiplied by density have standard names with specific_ instead of volume_.

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_parameterized_mesoscale_eddy_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

tendency_of_sea_water_salinity_expressed_as_salt_content_due_to_parameterized_eddy_advection

Unit: kg m-2 s-1
Unit ref: KSP2
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. 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. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_parameterized_submesoscale_eddy_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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 submesoscale eddy advection occurs on a spatial scale of the order of 1 km horizontally. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. There are also standard names for parameterized_mesoscale_eddy_advection which, along with parameterized_submesoscale_eddy_advection, contributes to the total parameterized eddy advection. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

northward_ocean_salt_transport_due_to_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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.

integral_wrt_time_of_surface_downward_sensible_heat_flux

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). The surface sensible heat flux, also called "turbulent" heat flux, is the exchange of heat between the surface and the air by motion of air. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

tendency_of_sea_water_salinity_due_to_parameterized_eddy_advection

Unit: 1e-3 s-1
Unit ref: PRSC
"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 salinity is the salt content of sea water, often on the Practical Salinity Scale of 1978. However, the unqualified term 'salinity' is generic and does not necessarily imply any particular method of calculation. The units of salinity are dimensionless and normally given as 1e-3 or 0.001 i.e. parts per thousand. There are standard names for the more precisely defined salinity quantities: sea_water_knudsen_salinity, S_K (used for salinity observations between 1901 and 1966), sea_water_cox_salinity, S_C (used for salinity observations between 1967 and 1977), sea_water_practical_salinity, S_P (used for salinity observations from 1978 to the present day), sea_water_absolute_salinity, S_A, sea_water_preformed_salinity, S_*, and sea_water_reference_salinity. Practical Salinity is reported on the Practical Salinity Scale of 1978 (PSS-78), and is usually based on the electrical conductivity of sea water in observations since the 1960s. Conversion of data between the observed scales follows: S_P = (S_K - 0.03) * (1.80655 / 1.805) and S_P = S_C, however the accuracy of the latter is dependent on whether chlorinity or conductivity was used to determine the S_C value, with this inconsistency driving the development of PSS-78. The more precise standard names should be used where appropriate for both modelled and observed salinities. In particular, the use of sea_water_salinity to describe salinity observations made from 1978 onwards is now deprecated in favor of the term sea_water_practical_salinity which is the salinity quantity stored by national data centers for post-1978 observations. The only exception to this is where the observed salinities are definitely known not to be recorded on the Practical Salinity Scale. The unit "parts per thousand" was used for sea_water_knudsen_salinity and sea_water_cox_salinity.

northward_sea_water_velocity_due_to_parameterized_mesoscale_eddies

Unit: m s-1
Unit ref: UVAA
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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 mesoscale eddies occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddies are represented in ocean models using schemes such as the Gent-McWilliams scheme.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content

Unit: W m-2
Unit ref: UFAA
"Content" indicates a quantity per unit area. The phrase "tendency_of_X" means derivative of X with respect to time. This tendency encompasses all processes that impact on the time changes for the heat content within a grid cell. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.

integral_wrt_depth_of_sea_water_potential_temperature_expressed_as_heat_content

Unit: J m-2
Unit ref: JMSQ
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. "expressed_as_heat_content" means that this quantity is calculated as the (assumed constant) specific heat capacity times density of sea water multiplied by the integral, over the specified layer of the ocean, of the sea water potential temperature wrt depth. "Content" indicates a quantity per unit area. 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.

tendency_of_ocean_eddy_kinetic_energy_content_due_to_parameterized_eddy_advection

Unit: W m-2
Unit ref: UFAA
"tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. 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.

ocean_mass_y_transport_due_to_advection_and_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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.

ocean_tracer_biharmonic_diffusivity_due_to_parameterized_mesoscale_eddy_advection

Unit: m4 s-1
Unit ref: M4S1
Diffusivity is also sometimes known as the coefficient of diffusion. Diffusion occurs as a result of a gradient in the spatial distribution of mass concentration, temperature or momentum. The diffusivity may be very different in the vertical and horizontal directions. "biharmonicdiffusivity" means diffusivity for use with a biharmonic diffusion operator. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

wind_gust_from_direction

Unit: degree
Unit ref: UAAA
The phrase "from_direction" is used in the construction X_from_direction and indicates the direction from which the velocity vector of X is coming. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. A gust is a sudden brief period of high wind speed. In an observed time series of wind speed, the gust wind speed can be indicated by a cell_methods of "maximum" for the time-interval. In an atmospheric model which has a parametrised calculation of gustiness, the gust wind speed may be separately diagnosed from the wind speed. 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".) In meteorological reports, the direction of the wind vector is usually (but not always) given as the direction from which it is blowing ("wind_from_direction") (westerly, northerly, etc.). In other contexts, such as atmospheric modelling, it is often natural to give the direction in the usual manner of vectors as the heading or the direction to which it is blowing ("wind_to_direction") (eastward, southward, etc.).

sea_water_x_velocity_due_to_parameterized_mesoscale_eddies

Unit: m s-1
Unit ref: UVAA
A velocity is a vector quantity. "x" indicates a vector component along the grid x-axis, positive with increasing x. 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 mesoscale eddies occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddies are represented in ocean models using schemes such as the Gent-McWilliams scheme. sea_water_x_velocity_due_to_parameterized_mesoscale_eddies is used in some parameterisations of lateral diffusion in the ocean.

integral_wrt_time_of_toa_outgoing_longwave_flux

Unit: W s m-2
Unit ref: WSMM
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. "toa" means top of atmosphere. "Longwave" means longwave radiation. The TOA outgoing longwave flux is the upwelling thermal radiative flux, often called the "outgoing longwave radiation" or "OLR". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

northward_ocean_freshwater_transport_due_to_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_parameterized_eddy_advection

Unit: W m-2
Unit ref: UFAA
"tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. 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. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

ocean_heat_x_transport_due_to_parameterized_eddy_advection

Unit: W
Unit ref: WATT
"x" indicates a vector component along the grid x-axis, positive with increasing x. 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.

integral_wrt_time_of_surface_downwelling_longwave_flux_in_air

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "longwave" means longwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

tendency_of_sea_water_temperature_due_to_parameterized_eddy_advection

Unit: K s-1
Unit ref: KPRS
The phrase "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.

ocean_tracer_laplacian_diffusivity_due_to_parameterized_mesoscale_eddy_advection

Unit: m2 s-1
Unit ref: SQMS
Diffusivity is also sometimes known as the coefficient of diffusion. Diffusion occurs as a result of a gradient in the spatial distribution of mass concentration, temperature or momentum. The diffusivity may be very different in the vertical and horizontal directions. "laplacian diffusivity" means diffusivity for use with a Laplacian diffusion operator. 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

integral_wrt_depth_of_sea_ice_temperature_expressed_as_heat_content

Unit: J m-2
Unit ref: JMSQ
The quantity with standard name integral_wrt_depth_of_sea_ice_temperature_expressed_as_heat_content is calculated relative to the heat content of ice at zero degrees Celsius, which is assumed to have a heat content of zero Joules. 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. "Content" indicates a quantity per unit area. Depth is the vertical distance below the surface.

integral_wrt_time_of_surface_net_downward_shortwave_flux

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). "Shortwave" means shortwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

ocean_heat_y_transport_due_to_parameterized_eddy_advection

Unit: W
Unit ref: WATT
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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.

northward_ocean_heat_transport_due_to_parameterized_eddy_advection

Unit: W
Unit ref: WATT
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. 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.

ocean_y_overturning_mass_streamfunction_due_to_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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.

integral_wrt_time_of_air_temperature_excess

Unit: K s
Unit ref: KSXX
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.

ocean_mass_x_transport_due_to_advection_and_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
"x" indicates a vector component along the grid x-axis, positive with increasing x. 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.

integral_wrt_depth_of_product_of_sea_water_density_and_potential_temperature

Unit: kg degree_C m-2
Unit ref: DKM2
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. 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. 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. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.

sea_water_y_velocity_due_to_parameterized_mesoscale_eddies

Unit: m s-1
Unit ref: UVAA
A velocity is a vector quantity. "y" indicates a vector component along the grid y-axis, positive with increasing y. 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 mesoscale eddies occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddies are represented in ocean models using schemes such as the Gent-McWilliams scheme. sea_water_y_velocity_due_to_parameterized_mesoscale_eddies is used in some parameterisations of lateral diffusion in the ocean.

integral_wrt_height_of_product_of_eastward_wind_and_specific_humidity

Unit: m2 s-1
Unit ref: SQMS
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. The phrase "wrt" means "with respect to". Height is the vertical distance above the surface. The phrase "product_of_X_and_Y" means X*Y. 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".) "Eastward" indicates a vector component which is positive when directed eastward (negative westward). Specific humidity is the mass fraction of water vapor in (moist) air.

graupel_fall_amount

Unit: kg m-2
Unit ref: KMP2
"Amount" means mass per unit area. Graupel consists of heavily rimed snow particles, often called snow pellets; often indistinguishable from very small soft hail except for the size convention that hail must have a diameter greater than 5 mm. Reference: American Meteorological Society Glossary http://glossary.ametsoc.org/wiki/Graupel.

integral_wrt_time_of_surface_net_downward_longwave_flux

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). "longwave" means longwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

eastward_sea_water_velocity_due_to_parameterized_mesoscale_eddies

Unit: m s-1
Unit ref: UVAA
"Eastward" indicates a vector component which is positive when directed eastward (negative westward). 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 mesoscale eddies occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddies are represented in ocean models using schemes such as the Gent-McWilliams scheme.

integral_wrt_time_of_surface_downward_eastward_stress

Unit: Pa s
Unit ref: PASS
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. The surface called "surface" means the lower boundary of the atmosphere. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward eastward" indicates the ZX component of a tensor. A downward eastward stress is a downward flux of eastward momentum, which accelerates the lower medium eastward and the upper medium westward. The surface downward stress is the wind stress on the surface.

tendency_of_sea_water_potential_temperature_expressed_as_heat_content_due_to_parameterized_mesoscale_eddy_diffusion

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the potential temperature of the sea water in the grid cell. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. 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 mesoscale eddy diffusive processes include diffusion along neutral directions in the interior of the ocean and horizontal diffusion in the surface boundary layer. The processes occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks.

y_wind_gust

Unit: m s-1
Unit ref: UVAA
"y" indicates a vector component along the grid y-axis, positive with increasing y. 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.) A gust is a sudden brief period of high wind speed. In an observed time series of wind speed, the gust wind speed can be indicated by a cell_methods of maximum for the time-interval. In an atmospheric model which has a parametrised calculation of gustiness, the gust wind speed may be separately diagnosed from the wind speed.

ocean_meridional_overturning_mass_streamfunction_due_to_parameterized_eddy_advection

Unit: kg s-1
Unit ref: KGPS
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.

tendency_of_sea_water_conservative_temperature_expressed_as_heat_content_due_to_parameterized_eddy_advection

Unit: W m-2
Unit ref: UFAA
The phrase "tendency_of_X" means derivative of X with respect to time. "Content" indicates a quantity per unit area. The phrase "expressed_as_heat_content" means that this quantity is calculated as the specific heat capacity times density of sea water multiplied by the conservative temperature of the sea water in the grid cell. 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. 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. Additionally, when the parameterized advective process is represented in the model as a skew-diffusion rather than an advection, then the parameterized skew diffusion should be included in this diagnostic. The convergence of a skew-flux is identical (in the continuous formulation) to the convergence of an advective flux, making their tendencies the same.

integral_wrt_time_of_surface_downwelling_shortwave_flux_in_air

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "shortwave" means shortwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". Surface downwelling shortwave is the sum of direct and diffuse solar radiation incident on the surface, and is sometimes called "global radiation". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

integral_wrt_height_of_product_of_northward_wind_and_specific_humidity

Unit: m2 s-1
Unit ref: SQMS
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. The phrase "wrt" means "with respect to". Height is the vertical distance above the surface. The phrase "product_of_X_and_Y" means X*Y. 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".) "Northward" indicates a vector component which is positive when directed northward (negative southward). Specific humidity is the mass fraction of water vapor in (moist) air.

integral_wrt_time_of_surface_downward_latent_heat_flux

Unit: W s m-2
Unit ref: WSMM
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. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). The surface latent heat flux is the exchange of heat between the surface and the air on account of evaporation (including sublimation). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

integral_wrt_depth_of_product_of_sea_water_density_and_salinity

Unit: 1e-3 kg m-2
Unit ref: KMP2
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. 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. 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. Sea water salinity is the salt content of sea water, often on the Practical Salinity Scale of 1978. However, the unqualified term 'salinity' is generic and does not necessarily imply any particular method of calculation. The units of salinity are dimensionless and the units attribute should normally be given as 1e-3 or 0.001 i.e. parts per thousand. There are standard names for the more precisely defined salinity quantities sea_water_knudsen_salinity, S_K (used for salinity observations between 1901 and 1966), sea_water_cox_salinity, S_C (used for salinity observations between 1967 and 1977), sea_water_practical_salinity, S_P (used for salinity observations from 1978 to the present day), sea_water_absolute_salinity, S_A, sea_water_preformed_salinity, S_*, and sea_water_reference_salinity. Practical Salinity is reported on the Practical Salinity Scale of 1978 (PSS-78), and is usually based on the electrical conductivity of sea water in observations since the 1960s. Conversion of data between the observed scales follows S_P = (S_K - 0.03) * (1.80655 / 1.805) and S_P = S_C, however the accuracy of the latter is dependent on whether chlorinity or conductivity was used to determine the S_C value, with this inconsistency driving the development of PSS-78. The more precise standard names should be used where appropriate for both modelled and observed salinities. In particular, the use of sea_water_salinity to describe salinity observations made from 1978 onwards is now deprecated in favor of the term sea_water_practical_salinity which is the salinity quantity stored by national data centers for post-1978 observations. The only exception to this is where the observed salinities are definitely known not to be recorded on the Practical Salinity Scale. Practical salinity units are dimensionless. The unit "parts per thousand" was used for sea_water_knudsen_salinity and sea_water_cox_salinity.

northward_ocean_heat_transport_due_to_parameterized_mesoscale_eddy_advection

Unit: W
Unit ref: WATT
"Northward" indicates a vector component which is positive when directed northward (negative southward). 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 mesoscale eddy advection occurs on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddy advection is represented in ocean models using schemes such as the Gent-McWilliams scheme. There are also standard names for parameterized_submesoscale_eddy_advection which, along with parameterized_mesoscale_eddy_advection, contributes to the total parameterized eddy advection.

integral_wrt_depth_of_sea_water_practical_salinity

Unit: m
Unit ref: ULAA
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. Depth is the vertical distance below the surface. Practical Salinity, S_P, is a determination of the salinity of sea water, based on its electrical conductance. The measured conductance, corrected for temperature and pressure, is compared to the conductance of a standard potassium chloride solution, producing a value on the Practical Salinity Scale of 1978 (PSS-78). This name should not be used to describe salinity observations made before 1978, or ones not based on conductance measurements. Conversion of Practical Salinity to other precisely defined salinity measures should use the appropriate formulas specified by TEOS-10. Other standard names for precisely defined salinity quantities are sea_water_absolute_salinity (S_A); sea_water_preformed_salinity (S_*), sea_water_reference_salinity (S_R); sea_water_cox_salinity (S_C), used for salinity observations between 1967 and 1977; and sea_water_knudsen_salinity (S_K), used for salinity observations between 1901 and 1966. Salinity quantities that do not match any of the precise definitions should be given the more general standard name of sea_water_salinity. Reference: www.teos-10.org; Lewis, 1980 doi:10.1109/JOE.1980.1145448.

integral_wrt_depth_of_sea_water_temperature_in_ocean_layer

Unit: K m
Unit ref: KMTX
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. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. 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.

integral_wrt_time_of_surface_downward_northward_stress

Unit: Pa s
Unit ref: PASS
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. The surface called "surface" means the lower boundary of the atmosphere. "Northward" indicates a vector component which is positive when directed northward (negative southward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward northward" indicates the ZY component of a tensor. A downward northward stress is a downward flux of northward momentum, which accelerates the lower medium northward and the upper medium southward. The surface downward stress is the wind stress on the surface.

integral_wrt_time_of_toa_net_downward_shortwave_flux

Unit: W s m-2
Unit ref: WSMM
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. "toa" means top of atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). "Shortwave" means shortwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.

integral_wrt_depth_of_product_of_sea_water_density_and_conservative_temperature

Unit: kg degree_C m-2
Unit ref: DKM2
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. 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. 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. 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.

integral_wrt_time_of_air_temperature_deficit

Unit: K s
Unit ref: KSXX
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.

upward_sea_water_velocity_due_to_parameterized_mesoscale_eddies

Unit: m s-1
Unit ref: UVAA
A velocity is a vector quantity. "Upward" indicates a vector component which is positive when directed upward (negative downward). 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 mesoscale eddies occur on a spatial scale of many tens of kilometres and an evolutionary time of weeks. Reference: James C. McWilliams 2016, Submesoscale currents in the ocean, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 472, issue 2189. DOI: 10.1098/rspa.2016.0117. Parameterized mesoscale eddies are represented in ocean models using schemes such as the Gent-McWilliams scheme.

ocean_integral_of_sea_water_temperature_wrt_depth

Unit: K m
Unit ref: http://vocab.ndg.nerc.ac.uk/term/P061/40/KMTX
"integral_of_Y_wrt_X" 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. 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.