@@ -119,7 +119,7 @@ The units of this parameter are geopotential metres. A geopotential metre is app
198|128|198|src|Skin reservoir content|m of water equivalent|This parameter is the amount of water in the vegetation canopy and/or in a thin layer on the soil. It represents the amount of rain intercepted by foliage, and water from dew. The maximum amount of 'skin reservoir content' a grid box can hold depends on the type of vegetation, and may be zero. Water leaves the 'skin reservoir' by evaporation. [ See further information.](https://www.ecmwf.int/sites/default/files/elibrary/2016/17117-part- iv-physical-processes.pdf#subsection.H.6.1) |sfc_an,sfc_an_land|INST|redGG-N320,redGG-N1280|0|src|lwe_thickness_of_canopy_water_amount|||m|1|||Skin Reservoir Content|mon|atmos|gr|sf00
201|128|201|mx2t|Maximum temperature at 2 metres since previous post-processing|K|This parameter is the highest temperature of air at 2m above the surface of land, sea or in-land waters since the parameter was last archived in a particular forecast. 2m temperature is calculated by interpolating between the lowest model level and the Earth's surface, taking account of the atmospheric conditions.[ See further information ](https://www.ecmwf.int/sites/default/files/elibrary/2016/17117-part-iv- physical-processes.pdf#subsection.3.10.3). This parameter has units of kelvin (K). Temperature measured in kelvin can be converted to degrees Celsius (°C) by subtracting 273.15. |sfc_fc|MAX|redGG-N320|6|tasmax|air_temperature||time: max|K|1|||Maximum Near-Surface Air Temperature|Amon|atmos|gr|sf12
202|128|202|mn2t|Minimum temperature at 2 metres since previous post-processing|K|This parameter is the lowest temperature of air at 2m above the surface of land, sea or in-land waters since the parameter was last archived in a particular forecast. 2m temperature is calculated by interpolating between the lowest model level and the Earth's surface, taking account of the atmospheric conditions.[ See further information ](https://www.ecmwf.int/sites/default/files/elibrary/2016/17117-part-iv- physical-processes.pdf#subsection.3.10.3). This parameter has units of kelvin (K). Temperature measured in kelvin can be converted to degrees Celsius (°C) by subtracting 273.15. |sfc_fc|MIN|redGG-N320|6|tasmin|air_temperature||time: min|K|1|||Minimum Near-Surface Air Temperature|Amon|atmos|gr|sf12
203|128|203|o3|Ozone mass mixing ratio|kg kg-1|This parameter is the mass of ozone per kilogram of air. In the ECMWF Integrated Forecasting System (IFS), there is a simplified representation of ozone chemistry (including representation of the chemistry which has caused the ozone hole). Ozone is also transported around in the atmosphere through the motion of air.[ See further documentation](https://www.ecmwf.int/sites/default/files/elibrary/2016/16648-part- iv-physical-processes.pdf#chapter.10). Naturally occurring ozone in the stratosphere helps protect organisms at the surface of the Earth from the harmful effects of ultraviolet (UV) radiation from the Sun. Ozone near the surface, often produced because of pollution, is harmful to organisms. Most of the IFS chemical species are archived as mass mixing ratios [kg kg-1].[ This link](https://confluence.ecmwf.int/pages/viewpage.action?pageId=153391710) explains how to convert to concentration in terms of mass per unit volume. |ml_an,pl_an|INST|redGG-N320,redGG-N320|1|o3|mass_fraction_of_ozone_in_air|||kg kg-1|1|||Ozone Mass Mixing Ratio|mon|atmos|gr|pl00
203|128|203|o3|Ozone mass mixing ratio|kg kg-1|This parameter is the mass of ozone per kilogram of air. In the ECMWF Integrated Forecasting System (IFS), there is a simplified representation of ozone chemistry (including representation of the chemistry which has caused the ozone hole). Ozone is also transported around in the atmosphere through the motion of air.[ See further documentation](https://www.ecmwf.int/sites/default/files/elibrary/2016/16648-part- iv-physical-processes.pdf#chapter.10). Naturally occurring ozone in the stratosphere helps protect organisms at the surface of the Earth from the harmful effects of ultraviolet (UV) radiation from the Sun. Ozone near the surface, often produced because of pollution, is harmful to organisms. Most of the IFS chemical species are archived as mass mixing ratios [kg kg-1].[ This link](https://confluence.ecmwf.int/pages/viewpage.action?pageId=153391710) explains how to convert to concentration in terms of mass per unit volume. |ml_an,pl_an|INST|redGG-N320,redGG-N320|6|o3|mass_fraction_of_ozone_in_air|||kg kg-1|1|||Ozone Mass Mixing Ratio|mon|atmos|gr|pl00
205|128|205|ro|Runoff|m|Some water from rainfall, melting snow, or deep in the soil, stays stored in the soil. Otherwise, the water drains away, either over the surface (surface runoff), or under the ground (sub-surface runoff) and the sum of these two is simply called 'runoff'. This parameter is the total amount of water accumulated over a [particular time period which depends on the data extracted](https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation#ERA5:datadocumentation- Meanrates/fluxesandaccumulations).The units of runoff are depth in metres. This is the depth the water would have if it were spread evenly over the [grid box](https://confluence.ecmwf.int/display/CKB/Model+grid+box+and+time+step). Care should be taken when comparing model parameters with observations, because observations are often local to a particular point rather than averaged over a grid square area. Observations are also often taken in different units, such as mm/day, rather than the accumulated metres produced here. Runoff is a measure of the availability of water in the soil, and can, for example, be used as an indicator of drought or flood. More information about how runoff is calculated is given in the [ IFS Physical Processes documentation](https://www.ecmwf.int/sites/default/files/elibrary/2016/17117-part- iv-physical-processes.pdf#subsection.H.6.3). |sfc_fc,sfc_fc_land|ACC|redGG-N320|6|mrro|runoff_flux|runoff_amount||kg m-2 s-1|1.0/3.6||derived from the hourly accumulated quantity and assuming a constant density of water of 1 kg m-3|Total Runoff|Lmon|land|gr|sf12
206|128|206|tco3|Total column ozone|kg m-2|This parameter is the total amount of ozone in a column of air extending from the surface of the Earth to the top of the atmosphere. This parameter can also be referred to as total ozone, or vertically integrated ozone. The values are dominated by ozone within the stratosphere. In the ECMWF Integrated Forecasting System (IFS), there is a simplified representation of ozone chemistry (including representation of the chemistry which has caused the ozone hole). Ozone is also transported around in the atmosphere through the motion of air.[ See further documentation ](https://www.ecmwf.int/sites/default/files/elibrary/2016/16648-part-iv- physical-processes.pdf#chapter.10). Naturally occurring ozone in the stratosphere helps protect organisms at the surface of the Earth from the harmful effects of ultraviolet (UV) radiation from the Sun. Ozone near the surface, often produced because of pollution, is harmful to organisms. In the IFS, the units for total ozone are kilograms per square metre, but before 12/06/2001 dobson units were used. Dobson units (DU) are still used extensively for total column ozone. 1 DU = 2.1415E-5 kg m-2 |sfc_an|INST|redGG-N320|1|tco3|atmosphere_mass_content_of_ozone|||kg m-2|1|||Total Column Ozone|mon|atmos|gr|sf00
208|128|208|tsrc|Top net solar radiation, clear sky|J m-2|This parameter is the incoming solar radiation (also known as shortwave radiation) minus the outgoing solar radiation at the top of the atmosphere, assuming clear-sky (cloudless) conditions. It is the amount of radiation passing through a horizontal plane. The incoming solar radiation is the amount received from the Sun. The outgoing solar radiation is the amount reflected and scattered by the Earth's atmosphere and surface, assuming clear-sky (cloudless) conditions. [See further documentation](https://www.ecmwf.int/sites/default/files/elibrary/2015/18490-radiation- quantities-ecmwf-model-and-mars.pdf). Clear-sky radiation quantities are computed for exactly the same atmospheric conditions of temperature, humidity, ozone, trace gases and aerosol as the total-sky (clouds included) quantities, but assuming that the clouds are not there. This parameter is [accumulated over a particular time period](https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation#ERA5:datadocumentation- Meanrates/fluxesandaccumulations) which depends on the data extracted. The units are joules per square metre (J m-2). To convert to watts per square metre (W m-2), the accumulated values should be divided by the accumulation period expressed in seconds. The ECMWF convention for vertical fluxes is positive downwards. |sfc_fc|ACC|redGG-N320|1|rstcs|toa_net_downward_shortwave_flux_assuming_clear_sky|||W m-2|1.0/3600|down||TOA Net Downward Shortwave Flux Assuming Clear Sky|mon|atmos|gr|sf12
