CEOS EO HANDBOOK – MEASUREMENTS
Measurements > Atmosphere >
Trace gases (excluding ozone)


Trace gases other than ozone may be divided into three categories: greenhouse gases affecting climate change; chemically aggressive gases affecting the environment (including the biosphere); and, gases and radicals impacting on the ozone cycle, thereby affecting both climate and environment. Measurements include the concentration of trace gasses, column totals and integrated column measurements, and profiles of gas concentration.
Detailed MeasurementDescription*InstrumentsTimeline
BrO (column/profile)BrO = Bromine monoxide. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].7 instruments
C2H2 (column/profile)C2H2 = Acetylene. Requested in the troposphere (layers: LT, HT) - Physical unit: [ ppm ] - Accuracy unit: [ % ].1 instrument
C2H6 (column/profile)C2H6 = Ethane. Requested in the troposphere (layers: LT, HT) - Physical unit: [ ppm ] - Accuracy unit: [ % ].1 instrument
CFC-11 (column/profile)CFC-11 = Trichlorofluoromethane = Freon-11. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
CFC-12 (column/profile)CFC-12 = Dichlorodifluoromethane = Freon-12. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
CH3Br (column/profile)CH3BR = Methyl Bromide. Physical unit: [ ppm ] - Accuracy unit: [ % ].0 instruments
CH4 Mole Fraction
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3D field of amount of CH4 (Methane, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles) - Resolution Units km, Measuring Units molecules.cm-2, Uncertainty Units %40 instruments
CH4 Total Column
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2D field of total amount of CH4 molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
CH4 Tropospheric Column
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2D field of total amount of CH4 molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
CHOCHO (column/profile)CHOCHO = Physical unit: [ ppm ] - Accuracy unit: [ % ].3 instruments
ClO (column/profile)ClO = Chlorine monoxide = Hypochlorite. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].3 instruments
ClONO2 (column/profile)ClONO2 = Chlorine nitrate. Requested from mid-troposphere to TOA (layers: HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
CO Mole Fraction
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3D field of amount of CO (Carbon monoxide, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles) - Resolution Units km14 instruments
CO Total Column2D field of total amount of CO molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %1 instrument
CO Tropospheric Column
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2D field of total amount of CO molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause. CO = Carbon monoxide. Requested from surface to low stratosphere (layers: LT, HT, LS) + Total column - Measuring Units molecules.cm-2, Uncertainty Units %, Physical unit [ ppm ], Accuracy unit [ % ]0 instruments
CO2 Mole Fraction
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3D field of amount of CO2 (Carbon dioxide, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles) - Resolution Units km, Measuring Units molecules.cm-2, Uncertainty Units %34 instruments
CO2 Total Column
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2D field of total amount of CO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %2 instruments
CO2 Tropospheric Column
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2D field of total amount of CO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
COS (column/profile)COS = Carbonyl sulfide. Requested from surface to low stratosphere (layers: LT, HT, LS) - Physical unit: [ ppm ] - Accuracy unit: [ % ].0 instruments
HCFC-22 (column/profile)HCFC-22 = Chlorodifluoromethane or difluoromonochloromethane . Physical unit: [ ppm ] - Accuracy unit: [ % ].1 instrument
HCHO Mole Fraction3D field of amount of HCHO (Formaldehyde, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles).7 instruments
HCHO Total Column2D field of total amount of HCHO molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %1 instrument
HCHO Tropospheric Column
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2D field of total amount of HCHO molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
HCl (column/profile)HCl = Hydrogen chloride. Requested from mid-troposphere to TOA (layers: HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
HDO (column/profile)
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HDO = Water vapour (with one hydrogen nucleus replaced by its deuterium isotope). Requested from low stratosphere to TOA (layers: LS and HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].4 instruments
HNO3 (column/profile)HNO3 = Nitric acid. Requested from surface to TOA (layers: LT, HT, LS, HS&M) + Total column - Physical unit: [ ppm ] - Accuracy unit: [ % ].9 instruments
HNO3 Mole Fraction3D field of amount of HNO3 (Nitric acid, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles)1 instrument
N2O (column/profile)N2O = Nitrous oxide. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].10 instruments
N2O5 (column/profile)N2O5 = Nitrogen pentoxide. Requested in the troposphere (layers: LT, HT) - Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
NH3 Total Column2D field of total amount of NH3 molecules (Ammonia) per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere.1 instrument
NO (column/profile)NO = Nitric oxide. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].3 instruments
NO2 Mole Fraction3D field of amount of NO2 (Nitrogen peroxide, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles) - Resolution Units km CO2 = Carbon dioxide. Requested from surface to TOA (layers: LT, HT, LS, HS&M) + Total column - Measuring Units molecules.cm-2, Uncertainty Units %, Physical unit [ ppm ], Accuracy unit: [ % ]20 instruments
NO2 Total Column2D field of total amount of NO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %2 instruments
NO2 Tropospheric Column
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2D field of total amount of NO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
OClO (column/profile)OClO = chlorate. Physical unit: [ ppm ] - Accuracy unit: [ % ].2 instruments
OH (column/profile)OH = Hydroxil radical. Requested from surface to TOA (layers: LT, HT, LS, HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].1 instrument
PAN (column/profile)PAN = Peroxy Acetyl Nitrate. Requested in the troposphere (layers: LT, HT) - Physical unit: [ ppm ] - Accuracy unit: [ % ].0 instruments
pCO2
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Partial pressure of carbon dioxide at the surface of the sea - Measuring and Uncertainty Units microatm0 instruments
PSC (column/profile)PSC = Polar Stratospheric Clouds. Requested in the lower stratosphere (layer: LS) - Accuracy expressed as Hit Rate [ HR ] and False Alarm Rate [ FAR ].0 instruments
SF6 (column/profile)SF6 = Sulfur exafluoride. Requested from low stratosphere to TOA (layers: LS and HS&M) - Physical unit: [ ppm ] - Accuracy unit: [ % ].1 instrument
SO2 Mole Fraction3D field of amount of SO2 (Sulfur dioxide, expressed in moles) divided by the total amount of all constituents in dry air (also expressed in moles) - Measuring Units molecules.cm-2, Uncertainty Units %10 instruments
SO2 Total Column2D field of total amount of SO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the upper edge of the atmosphere - Measuring Units molecules.cm-2, Uncertainty Units %4 instruments
SO2 Tropospheric Column
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2D field of total amount of SO2 molecules per unit area in an atmospheric column extending from the Earth’s surface to the tropopause - Measuring Units molecules.cm-2, Uncertainty Units %0 instruments
* Description adapted from WMO.