IUPAC: chlorane, PubChem CID: 313, CAS Number: 7647-01-0, in gas phase
IUPAC: butane, PubChem CID: 7843, CAS Number: 106-97-8, in gas phase
IUPAC: ethyl formate, PubChem CID: 8025, CAS Number: 109-94-4, in gas phase
IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in particle phase, TSP
C6Hn, n={14, 12} (sum of 3-methylpentane and cyclohexane)
sum of 3-methylpentane and cyclohexane, in gas phase
Air temperature (at specified distance from reference surface)
IUPAC: cobalt-60, PubChem CID: 61492, CAS Number: 10198-40-0
IUPAC: 2-Methylbut-3-en-2-ol, PubChem CID: 8257, CAS Number: 115-18-4, in gas phase
The total time in one day during which the direct solar irradiance is equal to or more than the threshold value for bright sunshine (the threshold being 120 W m-2 of direct solar irradiance).
IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in particle phase, TSP
IUPAC: propane, PubChem CID: 6334, CAS Number: 74-98-6, in gas phase
Particle volume concentration as a function of size, typically equivalent spherical radius or diameter.
Total number of detected flashes in the corresponding time interval and space unit. Note: The space unit (grid box) should be equal to the horizontal resolution and the accumulation time to the observing cycle.
IUPAC: acetaldehyde, PubChem CID: 177, CAS Number: 75-07-0, in gas phase
IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, TSP
Hygroscopic growth factor, 110 μm equivalent
IUPAC: chloro(iodo)methane, PubChem CID: 11644, CAS Number: 593-71-5, in gas phase
IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, TSP
IUPAC: Prop-2-enenitrile, PubChem CID: 7855, CAS Number: 107-13-1, in gas phase
IUPAC: barium, PubChem CID: 5355457, CAS Number: 7440-39-3, in particle phase, TSP
C2H3Cl2F (1,1-dichloro-2-fluoroethane, HCFC-141a)
IUPAC: 1,1-dichloro-2-fluoroethane, PubChem CID: 67936, CAS Number: 430-53-5, in gas phase
IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in total deposition
Downward radiant power per area unit, per solid angle, and per wavelength or wavenumber interval.
Number of cloud hydrometeors (or cloud particles) per unit volume. Cloud hydrometeors refer to liquid and/or ice cloud particles.
Radiation effective in causing actinic erythema
Yew pollen
IUPAC: propanoate, PubChem CID: 104745, CAS Number: 72-03-7, in total deposition
The AOD is the effective depth of the aerosol over a specified distance, from the viewpoint of radiation propagation: Vertical integral of spectral aerosol extinction coefficient AOD = exp(-K. Δz) where K is the extinction coefficient [km-1 ] and Δz the vertical path [km].
Sweet chestnut pollen
IUPAC: tellurium-132, PubChem CID: 6336614, CAS Number: 14234-28-7
Particle number concentration as a function of size, typically equivalent spherical radius or diameter. Size range: PM10
IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in total deposition
CCl2F2 (dichlorodifluoromethane, CFC-12)
IUPAC: dichloro(difluoro)methane, PubChem CID: 6391, CAS Number: 75-71-8, in gas phase
IUPAC: lanthanum-140, PubChem CID: 104882, CAS Number: 13981-28-7
C4H5F5 (1,1,1,3,3-pentafluorobutane, HFC-365mfc)
IUPAC: 1,1,1,3,3-pentafluorobutane, PubChem CID: 67884, CAS Number: 406-58-6, in gas phase
Metastable (excited) state of technetium-99 isotope, IUPAC: technetium-99, PubChem CID: 26476, CAS Number: 14133-76-7
IUPAC: mercury, PubChem CID: 23931, CAS Number: 7439-97-6, in particle phase, TSP
IUPAC: chloroform, PubChem CID: 6212, CAS Number: 67-66-3, in gas phase
C5H10 (sum of 1-pentene and 2-methyl-2-butene)
Temperature of an air parcel. Note, temperature is a fundamental property of matter as defined in the SI system.
IUPAC: molecular hydrogen, PubChem CID: 783, CAS Number: 1333-74-0, in gas phase
Humidity (at specified distance from reference surface)
IUPAC: barium, PubChem CID: 5355457, CAS Number: 7440-39-3, in particle phase, PM2.5
IUPAC: 3,7,7-trimethylbicyclo[4.1.0]hept-3-ene, PubChem CID: 26049, CAS Number: 13466-78-9, in gas phase
Upward radiant power per area unit, per solid angle, and per wavelength or wavenumber interval.
IUPAC: 2-methylpentane, PubChem CID: 7892, CAS Number: 107-83-5, in gas phase
IUPAC: manganese-56, PubChem CID: 114694, CAS Number: 14681-52-8
IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, TSP
IUPAC: Propan-2-yl nitrate, PubChem CID: 15575, CAS Number: 1712-64-7, in gas phase
IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in particle phase, TSP
IUPAC: prop-2-enal, PubChem CID: 7847, CAS Number: 107-02-8, in gas phase
IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM10
IUPAC: n/a, PubChem CID: 10129882, CAS Number: 1111-72-4, in gas phase
Cedar family pollen
Other chemical components, fine
Normalised radar cross section (NRCS) backscatter coefficient, also called sigma-0 ('sigma-nought'). The normalised measure of the radar return, measured in dB.
IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in gas phase
Olive pollen
C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, gamma-lindane, gamma-HCH), in air
IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in gas phase
IUPAC: Propan-1-ol, PubChem CID: 1031, CAS Number: 71-23-8, in gas phase
C3HF7 (1,1,1,2,3,3,3-Heptafluoropropane, HFC-227ea)
IUPAC: 1,1,1,2,3,3,3-heptafluoropropane, PubChem CID: 67940, CAS Number: 431-89-0, in gas phase
Plantain pollen
IUPAC: uranium-234, PubChem CID: 61704, CAS Number: 13966-29-5
Flux density of downwelling short-wave solar radiation, at the top of the atmosphere or a specified level within the atmosphere, including the Earth surface. [The term 'global (downward) shortwave irradiance' is sometimes used to specify that this flux is the sum of direct and diffuse components.]
IUPAC: indium-111, PubChem CID: 5462099, CAS Number: 15750-15-9
IUPAC: iodide, PubChem CID: 30165, CAS Number: 20461-54-5, in total deposition
IUPAC: thorium, PubChem CID: 23960, CAS Number: 7440-29-1, in particle phase, TSP
Pressure tendency is the character and amount of atmospheric pressure change for a three-hour or other specified period ending at the time of observation. Pressure tendency is composed of two parts, namely the characteristic of pressure tendency and amount of pressure tendency.
IUPAC: manganese-53, PubChem CID: 167227, CAS Number: 14999-33-8
IUPAC: prop-1-yne, PubChem CID: 6335, CAS Number: 74-99-7, in gas phase
Ångström exponent for particle light extinction
A measure of dependence of the particle light extinction coefficient on wavelength expressed in power law relationship.
IUPAC: 1,2-xylene, PubChem CID: 7237, CAS Number: 95-47-6, in gas phase
IUPAC: yttrium-88, PubChem CID: 105173, CAS Number: 13982-36-0
C2H2Cl2 ((E)-1,2-dichloroethene, trans-1,2-dichloroethene)
IUPAC: (E)-1,2-dichloroethene, PubChem CID: 638186, CAS Number: 156-60-5, in gas phase
IUPAC: pent-1-ene, PubChem CID: 8004, CAS Number: 109-67-1, in gas phase
The area weighted mean diameter of the aerosol particles.
IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in particle phase, TSP
CF4 (tetrafluoromethane, carbon tetrafluoride, perfluoromethane, PFC-14)
IUPAC: tetrafluoromethane, PubChem CID: 6393, CAS Number: 75-73-0, in gas phase
A 2D array of backscatter coefficients as a function of Doppler shift and signal delay, derived from GNSS reflectometry.
Brassica pollen
IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, PM2.5
Pine pollen
Mass of particles per unit volume of air, size range: PM1
Melandrium pollen
The product of the total volume backscatter coefficient and the atmospheric two-way transmission of the layers between the instrument and the observed volume. The total volume backscatter coefficient is the sum of all backscatter coefficients from the atmosphere (including from molecules and particles) accounting for all polarizations. The atmospheric two-way transmission accounts for the total volume (molecular and particulate and all polarizations) extinction along the path from the instrument to the observed volume and back.
CBrF3 (bromotrifluoromethane, Halon 1301)
IUPAC: bromo(trifluoro)methane, PubChem CID: 6384, CAS Number: 75-63-8, in gas phase
Amaranth family pollen
A part of cloud optical depth which results from a vertical integral of light extinction by cloud particles between the bottom and top of a cloud layer.
IUPAC: cesium-137, PubChem CID: 5486527, CAS Number: 10045-97-3
C2H2F4 (1,1,1,2-tetrafluoroethane, HFC-134a)
IUPAC: 1,1,1,2-tetrafluoroethane, PubChem CID: 13129, CAS Number: 811-97-2, in gas phase
Field of total column mass of volcanic ash
IUPAC: lead-212, PubChem CID: 6335491, CAS Number: 15092-94-1
IUPAC: dibromomethane, PubChem CID: 3024, CAS Number: 74-95-3, in gas phase
IUPAC: 2-methylprop-1-ene, PubChem CID: 8255, CAS Number: 115-11-7, in gas phase
IUPAC: 1,7,7-trimethyltricyclo[2.2.1.02,6]heptane, PubChem CID: 79035, CAS Number: 508-32-7, in gas phase
IUPAC: strontium, PubChem CID: 5359327, CAS Number: 7440-24-6, in particle phase, PM2.5
C5Hn, n=10 (sum of 3-methyl-1-butene and cyclopentene)
Sum of 3-methyl-1-butene and cyclopentane, in gas phase
Occurrence of precipitation during last period (yes/no)
IUPAC: n/a, PubChem CID: 167013, CAS Number: 14158-34-0
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, TSP
IUPAC: acetylene, PubChem CID: 6326, CAS Number: 74-86-2, in gas phase
IUPAC: ethyl acetate, PubChem CID: 8857, CAS Number: 141-78-6, in gas phase
IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in total deposition
Sum of HNO3 (nitric acid) and NO3- (nitrate)
C4H6O ((E)-crotonaldehyde, trans-2-butenal)
IUPAC: (2E)-but-2-enal, PubChem CID: 447466, CAS Number: 123-73-9, in gas phase
Carbonaceous fraction of particulate matter that is thermally stable in an inert atmosphere to high temperatures near 4000 K and can only be gasified by oxidation starting at temperatures above 340 degC. It is assumed to be inert and non-volatile under atmospheric conditions and insoluble in any solvent. Size range: PM10
C12H8Cl6 (aldrin), in total precipitation
IUPAC: (1R,4S,4aS,5S,8R,8aR)-1,2,3,4,10,10-Hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene, PubChem CID: 2087, CAS Number: 309-00-2, in total precipitation
IUPAC: nitrogen trifluoride, PubChem CID: 24553, CAS Number: 7783-54-2, in gas phase
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in total deposition
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in particle phase, PM10
Maize pollen
IUPAC: bismuth-213, PubChem CID: 6337093, CAS Number: 15776-20-2
IUPAC: chloro nitrate, PubChem CID: 114934, CAS Number: 14545-72-3, in gas phase
Flux density of upwelling long-wave radiation, at the top of the atmosphere or at a specified level within the atmosphere, including the Earth surface.
Vertical column integral of spectral aerosol absorption coefficient: AAOD = exp(-K.Δz) where K is the absorption coefficient [km-1] and Δz the vertical path [km]
All pollen taxa
C2H3ClF2 (1-chloro-1,1-difluoroethane, HCFC-142b)
IUPAC: 1-chloro-1,1-difluoroethane, PubChem CID: 6388, CAS Number: 75-68-3, in gas phase
C2H2Cl2F2 (1,2-dichloro-1,1-difluoroethane, HCFC-132b)
IUPAC: 1,2-dichloro-1,1-difluoroethane, PubChem CID: 15442, CAS Number: 1649-08-7, in gas phase
IUPAC: heptane, PubChem CID: 8900, CAS Number: 142-82-5, in gas phase
IUPAC: n/a, PubChem CID: 104966, CAS Number: 14683-16-0
Polarity of the charge effectively lowered to ground during a lightning discharge.
IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in particle phase, TSP
C6Hn, n={14, 12} (sum of 2,3-dimethylbutane and methylcyclopentane)
sum of 2,3-dimethylbutane and methylcyclopentane, in gas phase
IUPAC: gallium-67, PubChem CID: 5464084, CAS Number: 14119-09-6
Extreme temperature (min, max) (at specified distance from reference surface)
IUPAC: 2,2,4-Trimethylpentane, PubChem CID: 10907, CAS Number: 540-84-1, in gas phase
C4H6O (2-methylprop-2-enal, methacrolein)
IUPAC: 2-methylprop-2-enal, PubChem CID: 6562, CAS Number: 78-85-3, in gas phase
A scaling factor describing the particle equivalent spherical size change as a function of relative humidity due to absorbing or evaporating water.
IUPAC: methanol, PubChem CID: 887, CAS Number: 67-56-1, in gas phase
IUPAC: methanesulfonate, PubChem CID: 85257, CAS Number: 16053-58-0, in particle phase, TSP
Hygroscopic growth factor, 35 μm equivalent
IUPAC: furan-2-carbaldehyde, PubChem CID: 7362, CAS Number: 98-01-1, in gas phase
C5H12 & C4H8 (sum of 2,2-dimethylpropane & c-2-butene)
IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, PM2.5
C4H5N (2-methyl-2-propenenitrile, methylacrylonitrile)
IUPAC: 2-Methylprop-2-enenitrile, PubChem CID: 31368, CAS Number: 126-98-7, in gas phase
IUPAC: bismuth, PubChem CID: 5359367, CAS Number: 7440-69-9, in particle phase, TSP
IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in total deposition
Spectrally integrated flux density of radiation received from the sun at the top of the atmosphere. Also called 'Total solar irradiance (TSI)'.
UV radiation measured at a higher spectral resolution (e.g. 1 nm) than multiband UV radiation
Holly pollen
IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, PM10
Atmospheric water in the solid phase (precipitating or not).
Oak pollen
Atmospheric water in the liquid phase (precipitating or not).
Sweetgum pollen
IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in total deposition
CCl4 (tetrachloromethane, carbon tetrachloride)
IUPAC: tetrachloromethane, PubChem CID: 5943, CAS Number: 56-23-5, in gas phase
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in gas phase
IUPAC: europium-152, PubChem CID: 104907, CAS Number: 14683-23-9
IUPAC: fluoroform, PubChem CID: 6373, CAS Number: 75-46-7, in gas phase
IUPAC: nickel, PubChem CID: 935, CAS Number: 7440-02-0, in particle phase, TSP
COF2 (difluoromethanal, carbonyl fluoride)
IUPAC: carbonyl difluoride, PubChem CID: 9623, CAS Number: 353-50-4, in gas phase
IUPAC: n/a, PubChem CID: 139859, CAS Number: 14940-63-7, in gas phase
Height of the surface above ground separating the planetary boundary layer (PBL) from the free atmosphere.
The ratio of the mass of water vapor in a sample of air and the mass of the dry air in that same air parcel. Note, mixing ratio is related to the concept of specific humidity, which is the fraction of water vapour in the air.
COS (OCS, carbon oxide sulfide, carbonyl sulfide)
IUPAC: carbonyl sulfide, PubChem CID: 10039, CAS Number: 463-58-1, in gas phase
IUPAC: methyl formate, PubChem CID: 7865, CAS Number: 107-31-3, in gas phase
IUPAC: hexane, PubChem CID: 8058, CAS Number: 110-54-3, in gas phase
IUPAC: cobalt-56, PubChem CID: 166998, CAS Number: 14093-03-9
IUPAC: krypton-85, PubChem CID: 104816, CAS Number: 13983-27-2
IUPAC: ammonium nitrate, PubChem CID: 22985, CAS Number: 6484-52-2, in particle phase, PM1
IUPAC: 2-Methylpropyl nitrate, PubChem CID: 10974, CAS Number: 928-45-0, in gas phase
IUPAC: lanthanum, PubChem CID: 23926, CAS Number: 7439-91-0, in particle phase, PM2.5
IUPAC: prop-1-ene, PubChem CID: 8252, CAS Number: 115-07-1, in gas phase
Ångström exponent for aerosol optical depth
A measure of dependence of the aerosol optical depth on wavelength expressed in power law relationship.
IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, TSP
IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-0, in particle phase
Aster family pollen
IUPAC: Furan, PubChem CID: 8029, CAS Number: 110-00-9, in gas phase
Cl3CCF3 (1,1,1-trichloro-2,2,2-trifluoroethane, CFC-113a)
IUPAC: 1,1,1-trichloro-2,2,2-trifluoroethane, PubChem CID: 9635, CAS Number: 354-58-5, in gas phase
Rumex (dock, sorrel) pollen
IUPAC: uranium-238, PubChem CID: n/a, CAS Number: n/a
Particle light scattering coefficient, PM1
A measure of light attenuation due to absorption by aerosol particles expressed as the Beer-Lambert Law exponent at unit path distance. Size range: PM1
Plane tree pollen
IUPAC: antimony-122, PubChem CID: 6335836, CAS Number: 14374-79-9
IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in total deposition
The product of the total volume backscatter coefficient and the atmospheric two-way transmission of the layers between the instrument and the observed volume presented in arbitrary units. The total volume backscatter coefficient is the sum of all backscatter coefficients from the atmosphere (including from molecules and particles) accounting for all polarizations. The atmospheric two-way transmission accounts for the total volume (molecular and particulate and all polarizations) extinction along the path from the instrument to the observed volume and back. The value of this variable in presented in relative, arbitrary units to account for observations of attenuated backscatter lacking final absolute calibrations.
IUPAC: tin, PubChem CID: 5352426, CAS Number: 7440-31-5, in particle phase, TSP
Weather existing at the time of observation, or under certain conditions, during the hour preceding the time of observation. [Manual on Codes (WMO-No. 306), Volume I.1. 2011 edition updated in 2019.]
Ångström exponent for particle light absorption
A measure of dependence of the particle light absorption coefficient on wavelength expressed in power law relationship.
IUPAC: 1,2,4-trimethylbenzene, PubChem CID: 7247, CAS Number: 95-36-3, in gas phase
IUPAC: zirconium-95, PubChem CID: 91573, CAS Number: 13967-71-0
IUPAC: 1,1-Dichloroethane, PubChem CID: 6365, CAS Number: 75-34-3, in gas phase
IUPAC: lithium, PubChem CID: 3028194, CAS Number: 7439-93-2, in particle phase, TSP
IUPAC: chloromethane, PubChem CID: 6327, CAS Number: 74-87-3, in gas phase
IUPAC: 2-methylbut-2-ene, PubChem CID: 10553, CAS Number: 513-35-9, in gas phase
Height above the surface to which atmospheric properties (wind speed, etc) or atmospheric constituents (aerosol, gases) are dispersed by turbulent vertical mixing
IUPAC: antimony, PubChem CID: 5354495, CAS Number: 7440-36-0, in particle phase, TSP
IUPAC: 7-methyl-3-methylideneocta-1, PubChem CID: 31253, CAS Number: 123-35-3, in gas phase
Flux density of short-wave solar radiation, as the difference between downwelling and upwelling radiation (positive for net downward), at the top of the atmosphere or at a specified level within the atmosphere, including the Earth surface.
IUPAC: azane, PubChem CID: 222, CAS Number: 7664-41-7, in particle phase, PM2.5
IUPAC: chromium, PubChem CID: 23976, CAS Number: 7440-47-3, in particle phase, TSP
Palm family pollen
C3H2F6 (1,1,1,3,3,3-hexafluoropropane, HFC-236fa)
IUPAC: 1,1,1,3,3,3-hexafluoropropane, PubChem CID: 12722, CAS Number: 690-39-1, in gas phase
IUPAC: methane, PubChem CID: 297, CAS Number: 74-82-8, in gas phase
Particle mass concentration (size fractionated)
Mass of particles per unit volume of air, size fractionated
Celery, carrot or parsley family pollen
The radiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. It is a directional quantity. Note: 'spectral radiance' is also used for measurements by radiometers and spectrometers, where it means the spectral radiance incident on the instrument integrated over the normalised spectral response function of the instrument. Historically, spectral radiance was called spectral intensity.
IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in particle phase, PM10
Poplar pollen
IUPAC: barium-140, PubChem CID: 6335490, CAS Number: 14798-08-4
C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in aerosol
IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in particle phase
IUPAC: 1,1,1,2,2-pentafluoroethane, PubChem CID: 9633, CAS Number: 354-33-6, in gas phase
IUPAC: radium-226, PubChem CID: 9877911, CAS Number: 13982-63-3
IUPAC: bromomethane, PubChem CID: 6323, CAS Number: 74-83-9, in gas phase
IUPAC: nitrite, PubChem CID: 946, CAS Number: 14797-65-0, in total deposition
IUPAC: ruthenium-106, PubChem CID: 26359, CAS Number: 13967-48-1
IUPAC: thallium, PubChem CID: 5359464, CAS Number: 7440-28-0, in particle phase, PM2.5
IUPAC: cyclohexane, PubChem CID: 8078, CAS Number: 110-82-7, in gas phase
IUPAC: potassium-42, PubChem CID: 11607897, CAS Number: 14378-21-3
IUPAC: cerium, PubChem CID: 23974, CAS Number: 7440-45-1, in particle phase, TSP
IUPAC: ethene, PubChem CID: 6325, CAS Number: 74-85-1, in gas phase
IUPAC: 1,4-xylene, PubChem CID: 7809, CAS Number: 106-42-3, in gas phase
IUPAC: toluene, PubChem CID: 1140, CAS Number: 108-88-3, in gas phase
IUPAC: strontium-89, PubChem CID: 5388880, CAS Number: 14158-27-1
Major inorganic components, TSP
IUPAC: But-2-enal, PubChem CID: 20138, CAS Number: 4170-30-3, in gas phase
Carbonaceous fraction of particulate matter that is thermally stable in an inert atmosphere to high temperatures near 4000 K and can only be gasified by oxidation starting at temperatures above 340 degC. It is assumed to be inert and non-volatile under atmospheric conditions and insoluble in any solvent. Size range: PM2.5
IUPAC: chloro(trifluoro)methane, PubChem CID: 6392, CAS Number: 75-72-9, in gas phase
The refractive index (of air) minus one. Particularly used for GNSS radio occultation observations.
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in gas phase
Elm pollen
IUPAC: nitric acid, PubChem CID: 944, CAS Number: 7697-37-2, in gas phase
IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in total deposition
Particle light absorption coefficient, PM1
Fir pollen
The area weighted mean radius of the aerosol particles.
Sedge family pollen
IUPAC: chloro(difluoro)methane, PubChem CID: 6372, CAS Number: 75-45-6, in gas phase
Height of the atmospheric layer in cloud where liquid-solid states transform into each other
IUPAC: (E)-pent-2-ene, PubChem CID: 5326161, CAS Number: 109-68-2, in gas phase
IUPAC: xenon-133, PubChem CID: 66376, CAS Number: 14932-42-4
Type of clouds of genera Cirrus, Cirrocumulus, or Cirrostratus. These occur between 3-8 km (polar regions), 5-13 km (temperate regions) and 6-18 km (tropics) above ground [ref: WMO, International Cloud Atlas, 2017 ed.]
IUPAC: strontium-85, PubChem CID: 5464271, CAS Number: 13967-73-2
IUPAC: n/a, PubChem CID: 5460627, CAS Number: 15656-19-6, in gas phase
IUPAC: but-1-ene, PubChem CID: 7844, CAS Number: 106-98-9, in gas phase
Hygroscopic particle light extinction growth factor
A scaling factor describing the particle extinction coefficient change as a function of relative humidity due to absorbing or evaporating water.
IUPAC: (Z)-but-2-ene, PubChem CID: 5287573, CAS Number: 590-18-1, in gas phase
Hygroscopic growth factor, 75 μm equivalent
IUPAC: styrene, PubChem CID: 7501, CAS Number: 100-42-5, in gas phase
IUPAC: 2,3-dimethylbutane, PubChem CID: 6589, CAS Number: 79-29-8, in gas phase
IUPAC: n/a, PubChem CID: 26873, CAS Number: 14762-75-5
Precipitation that reaches the surface in a stated period, expressed in terms of the vertical depth of water (or water equivalent in the case of solid precipitation) to which it would cover a horizontal projection of the Earth’s surface. Modified from: WMO-No. 8. Note: Sometimes called 'accumulated precipitation'.
IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, PM10
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM10
Detection of the time and location (latitude, longitude) of lightning events. Accuracy expressed in terms of Hit Rate and False Alarm Rate, which requires predetermination of a specific distance and time tolerance.
IUPAC: mercury, PubChem CID: 23931, CAS Number: 7439-97-6, in total deposition
Earth surface spectral bidirectional reflectance
Reflectance of the Earth surface as a function of viewing angle, incidence angle and wavelength, spectrally resolved. [The distribution of this variable is represented by the Bidirectional Reflectance Distribution Function (BRDF)].
Depth of the atmospheric layer in cloud where liquid-solid states transform into each other.
Rush family pollen
IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, TSP
The area weighted mean radius of ice particles, assimilated to spheres of the same volume.
Alder pollen
IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, TSP
IUPAC: (1R,4S,4aS,5S,8R,8aR)-1,2,3,4,10,10-Hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene, PubChem CID: 2087, CAS Number: 309-00-2, in particle phase
Mulberry family pollen
Horizontal wind direction at specified distance from reference surface
The direction of horizontal wind expressed in degrees at which the wind originates. This scalar quantity can be used to represent a value at a given location and an instantaneous time or average over spatio-temporal extent or values as a function of spatio-temporal coordinates. Note: 1) Wind direction is coded as 00 under 'Calm' conditions at which the average wind speed is less than or equal to 0.2 m/s (< 1 kt). The direction in this case is coded as 00; 2) Wind direction at stations within 1 degree of the North Pole or 1 degree of the South Pole should be measured so that the azimuth ring should be aligned with its zero coinciding with the Greenwich 0 degree meridian.
C14H10 (phenanthrene), in wet deposition
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in wet deposition
Solidago (goldenrod) pollen
IUPAC: iridium-192, PubChem CID: 66373, CAS Number: 14694-69-0
Height of the top of the cloud (highest cloud in case of multi-layer clouds) above mean sea level.
IUPAC: americium-241, PubChem CID: 104726, CAS Number: 14596-10-2
IUPAC: phosphorus, PubChem CID: 5462309, CAS Number: 7723-14-0, in particle phase, TSP
IUPAC: hydrogen peroxide, PubChem CID: 784, CAS Number: 7722-84-1, in gas phase
IUPAC: 2-methylhexane, PubChem CID: 11582, CAS Number: 591-76-4, in gas phase
Partial pressure of water vapour in an air parcel
IUPAC: methyl acetate, PubChem CID: 6584, CAS Number: 79-20-9, in gas phase
IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in particle phase, PM2.5
IUPAC: benzene, PubChem CID: 241, CAS Number: 71-43-2, in gas phase
IUPAC: cobalt-58, PubChem CID: 104844, CAS Number: 13981-38-9
IUPAC: radon-222, PubChem CID: 61773, CAS Number: 14859-67-7
C4H9NO3 (2-butyl nitrate, sec-butyl nitrate)
IUPAC: Butan-2-yl nitrite, PubChem CID: 13544, CAS Number: 924-43-6, in gas phase
IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in particle phase, PM10
IUPAC: propanal, PubChem CID: 527, CAS Number: 123-38-6, in gas phase
Particle surface area concentration as a function of size, typically equivalent spherical radius or diameter.
IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase
v (v component of horizontal wind vector)
North-south component of the horizontal wind vector, positive value for northward moving or south-to-north wind. This scalar quantity can be used to represent a value at given location and an instantaneous time or average over spatio-temporal extent or values as a function of spatio-temporal coordinates.
IUPAC: ethanol, PubChem CID: 702, CAS Number: 64-17-5, in gas phase
IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, PM10
IUPAC: bromo(dichloro)methane, PubChem CID: 6359, CAS Number: 75-27-4, in gas phase
IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, PM2.5
IUPAC: 3-Methylfuran, PubChem CID: 13587, CAS Number: 930-27-8, in gas phase
C2Br2F4 (1,2-dibromo-1,1,2,2-tetrafluoroethane, Halon 2402)
IUPAC: 1,2-dibromo-1,1,2,2-tetrafluoroethane, PubChem CID: 31301, CAS Number: 124-73-2, in gas phase
IUPAC: cobalt, PubChem CID: 104730, CAS Number: 7440-48-4, in total deposition
The area weighted mean radius of liquid water drops, assimilated to spheres of the same volume.
Spectrally integrated UV radiation
Hop pollen
IUPAC: neptunium-239, PubChem CID: 104958, CAS Number: 13968-59-7
IUPAC: formate, PubChem CID: 283, CAS Number: 71-47-6, in total deposition
Particle light scattering coefficient, TSP
A measure of light attenuation due to absorption by aerosol particles expressed as the Beer-Lambert Law exponent at unit path distance. Size range: TSP
Nettle pollen
IUPAC: antimony-125, PubChem CID: 6335317, CAS Number: 14234-35-6
Particle number concentration as a function of size, typically equivalent spherical radius or diameter. Size range: TSP
IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in total deposition
Upper-air atmospheric pressure
C2ClF5 (1-chloro-1,1,2,2,2-pentafluoroethane, CFC-115)
IUPAC: 1-chloro-1,1,2,2,2-pentafluoroethane, PubChem CID: 6430, CAS Number: 76-15-3, in gas phase
IUPAC: cerium-144, PubChem CID: 26874, CAS Number: 14762-78-8
IUPAC: formaldehyde, PubChem CID: 712, CAS Number: 50-00-0, in gas phase
IUPAC: molybdenum-99, PubChem CID: 104976, CAS Number: 14119-15-4
IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in particle phase, TSP
IUPAC: dibromo(chloro)methane, PubChem CID: 31296, CAS Number: 124-48-1, in gas phase
IUPAC: bromoform, PubChem CID: 5558, CAS Number: 75-25-2, in gas phase
IUPAC: cyclopentane, PubChem CID: 9253, CAS Number: 287-92-3, in gas phase
IUPAC: sulfuryl difluoride, PubChem CID: 17607, CAS Number: 2699-79-8, in gas phase
Turbulence type (low levels and wake vortex)
IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in particle phase, TSP
IUPAC: (4R)-1-methyl-4-prop-1-en-2-ylcyclohexene, PubChem CID: 440917, CAS Number: 5989-27-5, in gas phase
Flux density of upwelling long-wave radiation, as the difference between downwelling and upwelling radiation (positive for net downward) at a specified level within or at the top of the atmosphere, including the Earth surface.
IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, PM2.5
IUPAC: Ethyl nitrate, PubChem CID: 12259, CAS Number: 625-58-1, in gas phase
IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in particle phase, PM10
IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM1
IUPAC: carbon dioxide, PubChem CID: 280, CAS Number: 124-38-9, in gas phase
Amount of particles per unit volume of air
Other chemical components, coarse
Hophornbeam pollen
Ratio of reflected to incident radiation as a function of incident angle, reflected angle and wavelength. For a satellite measurement, these angles are the zenith and azimuth angles of the sun and the zenith and azimuth angle of the viewing instrument at the feature (surface and/or atmospheric column) being observed.
IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in aerosol
Olive family pollen
C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in wet precipitation
IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in wet deposition
IUPAC: 1,1,2,2,3,3,4,4-octafluorocyclobutane, PubChem CID: 8263, CAS Number: 115-25-3, in gas phase
C3H3F5 (1,1,1,3,3-Pentafluoropropane, HFC-245fa)
IUPAC: 1,1,1,3,3-pentafluoropropane, PubChem CID: 68030, CAS Number: 460-73-1, in gas phase
C18H12 (benz(a)anthracene), in total precipitation
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in total precipitation
IUPAC: thorium-232, PubChem CID: 11817119, CAS Number: n/a
Flux density of direct downwelling short-wave solar radiation, at the top of the atmosphere or at a specified level within the atmosphere, including the Earth surface.
Metastable (excited) state of silver-110 isotope, IUPAC: silver-110, PubChem CID: 104828, CAS Number: 14391-76-5
Kinetic energy density of turbulent motion of the air
IUPAC: fluoride, PubChem CID: 28179, CAS Number: 16984-48-8, in total deposition
IUPAC: thorium, PubChem CID: 23960, CAS Number: 7440-29-1, in particle phase, PM2.5
The pressure characteristic is an indication of how the pressure has changed during that period of time, for example, decreasing then increasing, or increasing and then increasing more rapidly.
IUPAC: chromium-51, PubChem CID: 104786, CAS Number: 14392-02-0
IUPAC: methylsulfanylmethane, PubChem CID: 1068, CAS Number: 75-18-3, in gas phase
Ratio of particle scattering coefficient to particle extinction coefficient or sum of particle absorption and scattering coefficients.
IUPAC: 1,3-xylene, PubChem CID: 7929, CAS Number: 108-38-3, in gas phase
IUPAC: strontium-91, PubChem CID: 6337043, CAS Number: 14331-91-0
Major inorganic components, fine
C2H2Cl2 ((Z)-1,2-dichloroethene, cis-1,2-dichloroethene)
IUPAC: (Z)-1,2-dichloroethene, PubChem CID: 643833, CAS Number: 156-59-2, in gas phase
Particle light hemispheric forward scattering coefficient
Incident radiative flux scattered into all forward angles, i.e. scattering_angle from zero to pi/2 radians.
IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in particle phase, PM2.5
IUPAC: 1,1,1,2,2,3,3,3-octafluoropropane, PubChem CID: 6432, CAS Number: 76-19-7, in gas phase
Observed variable - measurand (atmosphere)
The time delay of a GNSS radio signal passing along an atmospheric path from transmitter to receiver compared with the same path in vacuum, and scaled to refer to the equivalent vertical path.
IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, PM10
Aesculus pollen
IUPAC: n/a, PubChem CID: 3032552, CAS Number: 10102-44-0, in gas phase
Particle light absorption coefficient, TSP
Larch pollen
Mass of particles per unit volume of air, size range: PM10
Rose family pollen
IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in total deposition
IUPAC: neodymium-137
IUPAC: bromo-chloro-difluoromethane, PubChem CID: 9625, CAS Number: 353-59-3, in gas phase
Hazel pollen
The degree to which fog prevents light from passing through it. The term 'fog' refers to 'microscopic droplets [that] reduce horizontal visibility at the Earth’s surface to less than 1 km' [WMO, International Cloud Atlas, 2017 ed., https://cloudatlas.wmo.int/en/fog-compared-with-mist.html].
IUPAC: cesium-136, PubChem CID: 6335316, CAS Number: 14234-29-8
Type of clouds of genera Altocumulus, Altostratus, or Nimbostratus. These occur between 2-4 km (polar regions), 2-7 km (temperate regions) and 2-8 km (tropics) above ground [ref: WMO, International Cloud Atlas, 2017 ed.]
Volcanic ash particle mass concentration
3D field of mass mixing ratio of volcanic ash
IUPAC: 1,1,2-trichloroethene, PubChem CID: 6575, CAS Number: 79-01-6, in gas phase
The fraction of incident radiative flux scattered backward at 180 degrees.
IUPAC: 2-methylpropane, PubChem CID: 6360, CAS Number: 75-28-5, in gas phase
IUPAC: 1,1,1,2,2,2-hexafluoroethane, PubChem CID: 6431, CAS Number: 76-16-4, in gas phase
IUPAC: chlorobenzene, PubChem CID: 7964, CAS Number: 108-90-7, in gas phase
IUPAC: selenium, PubChem CID: 6326970, CAS Number: 7782-49-2, in particle phase, TSP
IUPAC: cyclopentene, PubChem CID: 8882, CAS Number: 142-29-0, in gas phase
IUPAC: sodium-24, PubChem CID: 6335498, CAS Number: 13982-04-2
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM2.5 - PM10
Lightning discharge distance from station
Distance of the lightning event from the corresponding station.
IUPAC: 1,3-dioxolane, PubChem CID: 12586, CAS Number: 646-06-0, in gas phase
IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in total deposition
Emissivity of the earth surface integrated over the thermal IR wavelength range and integrated hemispherically.
Polar Stratospheric Clouds occurrence. - Accuracy expressed as Hit Rate [HR] and False Alarm Rate [FAR]. Simplified: [FAR/HR]
Sum of NH3 (ammonia) and NH4+ (ammonium)
Hornbeam pollen
IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, PM2.5
The ratio of the amount of water vapour and the total amount of air including water vapour in an air parcel. Note, this concept is related to 'water vapour mass fraction'.
IUPAC: (1R,4S,4aS,5S,8R,8aR)-1,2,3,4,10,10-Hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene, PubChem CID: 2087, CAS Number: 309-00-2, in aerosol
Cladosporium spores
IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in total deposition
IUPAC: pyrene, PubChem CID: 31423, CAS Number: 129-00-0, in aerosol
Secale pollen
IUPAC: bismuth-212, PubChem CID: 6335500, CAS Number: 14913-49-6
IUPAC: nitro ethaneperoxoate, PubChem CID: 16782, CAS Number: 2278-22-0, in gas phase
Flux density of downwelling long-wave radiation, at a specified level within the atmosphere, including the Earth surface.
Atmospheric O2/N2 ratio
C2H3Cl2F (1,1-dichloro-1-fluoroethane, HCFC-141b)
IUPAC: 1,1-dichloro-1-fluoroethane, PubChem CID: 15586, CAS Number: 1717-00-6, in gas phase
IUPAC: gold-198, PubChem CID: 66274, CAS Number: 10043-49-9
IUPAC: rubidium, PubChem CID: 5357696, CAS Number: 7440-17-7, in particle phase, TSP
IUPAC: fluorane, PubChem CID: 14917, CAS Number: 7664-39-3, in gas phase
IUPAC: pentane, PubChem CID: 8003, CAS Number: 109-66-0, in gas phase
IUPAC: n/a, PubChem CID: 24855, CAS Number: 10043-66-0
Current incurred by the lightning discharge.
IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in particle phase, PM2.5
C6Hn, n={14, 12} (sum of 2,2-dimethylbutane and methylcyclopentane)
sum of 2,2-dimethylbutane and methylcyclopentane, in gas phase
Dew-point temperature (at specified distance from reference surface)
IUPAC: zinc-65, PubChem CID: 91574, CAS Number: 13982-39-3
IUPAC: Octane, PubChem CID: 356, CAS Number: 111-65-9, in gas phase
Hemispherically integrated reflectance of the Earth surface in the range 0.4-0.7 µm.
IUPAC: lithium, PubChem CID: 3028194, CAS Number: 7439-93-2, in particle phase, PM2.5
IUPAC: buta-1,3-diene, PubChem CID: 7845, CAS Number: 106-99-0, in gas phase
Particle mass concentration as a function of size, typically equivalent spherical radius or diameter.
Number of detected cloud-to-ground flashes in the corresponding time interval and space unit.
IUPAC: acetonitrile, PubChem CID: 6342, CAS Number: 75-05-8, in gas phase
IUPAC: methanesulfonate, PubChem CID: 85257, CAS Number: 16053-58-0, in particle phase, PM1
Hygroscopic growth factor, 165 μm equivalent
IUPAC: diiodomethane, PubChem CID: 6346, CAS Number: 75-11-6, in gas phase
IUPAC: pentanal, PubChem CID: 8063, CAS Number: 110-62-3, in gas phase
IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, PM10
IUPAC: Propanenitrile, PubChem CID: 7854, CAS Number: 107-12-0, in gas phase
IUPAC: bismuth, PubChem CID: 5359367, CAS Number: 7440-69-9, in particle phase, PM2.5
IUPAC: iron, PubChem CID: 23925, CAS Number: 7439-89-6, in total deposition
Spectrally resolved flux density of radiation received from the sun at the top of the atmosphere.
An ensemble mean size of cloud hydrometeors derived from size distribution. Cloud hydrometeors refer to liquid and/or ice cloud particles. For liquid phase clouds, the effective radius is defined as the area weighted mean radius of liquid water drops, assimilated to spheres of the same volume. The effective radius of cloud ice particles has been defined in the literature in different ways. Clear and detailed definition should be provided as how this parameter is derived.
UV radiation measured across several discrete, narrow wavebands (e.g. 10 nm) within the UV range, providing coarse spectral information
Sea-buckthorn pollen
Beech pollen
IUPAC: n/a, PubChem CID: 161029, CAS Number: 14158-32-8
Ginkgo pollen
IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in total deposition
IUPAC: trichloro(fluoro)methane, PubChem CID: 6389, CAS Number: 75-69-4, in gas phase
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in particle phase
IUPAC: neodymium-147, PubChem CID: 114848, CAS Number: 14269-74-0
IUPAC: difluoromethane, PubChem CID: 6345, CAS Number: 75-10-5, in gas phase
IUPAC: ruthenium-103, PubChem CID: 104749, CAS Number: 13968-53-1
IUPAC: nickel, PubChem CID: 935, CAS Number: 7440-02-0, in particle phase, PM10
IUPAC: carbon monoxide, PubChem CID: 281, CAS Number: 630-08-0, in gas phase
IUPAC: oxidane, PubChem CID: 962, CAS Number: 7732-18-5, in gas phase
Aggregate state of cloud particles, either water droplets/drops, snowflakes, ice/snow crystals, or mixed.
Total amount of water vapour per unit area in a vertical column of air. Integrated water vapour (IWV) is also known as precipitable water vapour (PWV).
IUPAC: oxaldehyde, PubChem CID: 7860, CAS Number: 107-22-2, in gas phase
IUPAC: 3-methylpentane, PubChem CID: 7282, CAS Number: 96-14-0, in gas phase
IUPAC: iron-59, PubChem CID: 104784, CAS Number: 14596-12-4
CO2 with C-14 isotope
IUPAC: ammonium nitrate, PubChem CID: 22985, CAS Number: 6484-52-2, in particle phase, TSP
IUPAC: Butyl nitrate, PubChem CID: 13567, CAS Number: 928-45-0, in gas phase
IUPAC: iron, PubChem CID: 23925, CAS Number: 7439-89-6, in particle phase, TSP
IUPAC: 2-oxopropanal, PubChem CID: 880, CAS Number: 78-98-8, in gas phase
IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM2.5
CO2 with O-18 isotope
Box pollen
IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-0, in particle phase, PM1
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in particle phase, PM10
Ash pollen
C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, gamma-lindane, gamma-HCH), in wet precipitation
IUPAC: Propan-2-ol, PubChem CID: 3776, CAS Number: 67-63-0, in gas phase
Vertical component of the 3-D wind vector. positive value for upward wind. This scalar quantity can be used to represent a value at given location and an instantaneous time or average over spatio-temporal extent or values as a function of spatio-temporal coordinates.
Sambucus (elder) pollen
IUPAC: uranium-235, PubChem CID: 61784, CAS Number: 15117-96-1
Flux density of upwelling short-wave radiation, at the top of the atmosphere or a specified level within the atmosphere, including the Earth surface.
Light backscattering coefficient, total aerosol
IUPAC: tin-113, PubChem CID: 6335514, CAS Number: 13966-06-8
IUPAC: phosphate, PubChem CID: 1061, CAS Number: 14265-44-2, in total deposition
The ratio of the mass of water vapour in the air to the mass of a moist air parcel, where the mass of the moist air parcel is the sum of the mass of water vapour and the dry air. Synonym: Moisture content. [Based on definition of M1750 in International Vocabulary of Meteorology (WMO-No. 182). 1992.]
IUPAC: tin, PubChem CID: 5352426, CAS Number: 7440-31-5, in particle phase, PM2.5
IUPAC: beryllium-7, PubChem CID: 6335489, CAS Number: 13966-02-4
Predominant characteristic of weather which had existed at the station during a given period of time. [Manual on Codes (WMO-No. 306), Volume I.1. 2011 edition updated in 2019.]
Ångström exponent for particle light scattering
A measure of dependence of the particle light scattering coefficient on wavelength expressed in power law relationship.
C8H10 (Sum of p-xylene and m-xylene, 1,3- and 1,4-dimethylbenzene)
Metastable (excited) state of yttrium-90 isotope, IUPAC: yttrium-90, PubChem CID: 104760, CAS Number: 10098-91-6
IUPAC: 1,2-dichloroethene, PubChem CID: 10900, CAS Number: 540-9-0, in gas phase
IUPAC: 2-methylbut-1-ene, PubChem CID: 11240, CAS Number: 563-46-2, in gas phase
IUPAC: nitrous oxide, PubChem CID: 948, CAS Number: 10024-97-2, in gas phase
Height of vertically localized aerosol layer above sea level
IUPAC: antimony, PubChem CID: 5354495, CAS Number: 7440-36-0, in particle phase, PM2.5
IUPAC: 6,6-dimethyl-2-methylidenebicyclo[3.1.1]heptane, PubChem CID: 14896, CAS Number: 127-91-3, in gas phase
Minimum distance between the direction vector of the ray (prior to bending) and the centre of the curvature of the ellipsoid describing the Earth, used particularly for GNSS radio occultation observations.
IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, TSP
Cypress family pollen
Mass of particles per unit volume of air, size range: PM2.5
Buttercup family pollen
Relative humidity (with respect to water)
The ratio of the amount fraction of the water vapour in the air to the corresponding amount fraction if the air were saturated with respect to water at a particular pressure and temperature. Relative humidity is typically reported in percent (%). [Based on definition of R1490 in International Vocabulary of Meteorology (WMO-No. 182). 1992.]
The radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. It is a directional quantity. Note: Historically, radiance was called 'intensity'.
IUPAC: 9H-fluorene, PubChem CID: 6853, CAS Number: 86-73-7, in gas phase
Chenopodium (goosefoot) pollen
Reflectance of the solar radiation from clouds
IUPAC: barium-133, PubChem CID: 5491664, CAS Number: 13981-41-4
IUPAC: 1,2,3,4,5,6-hexachlorobenzene, PubChem CID: 8370, CAS Number: 118-74-1, in gas phase
IUPAC: 1,1-difluoroethane, PubChem CID: 6368, CAS Number: 75-37-6, in gas phase
IUPAC: sulfur, PubChem CID: n/a, CAS Number: 7704-34-9, in total deposition
IUPAC: lead-214, PubChem CID: 6328551, CAS Number: 15067-28-4
IUPAC: dichloromethane, PubChem CID: 6344, CAS Number: 75-09-2, in gas phase
IUPAC: 2-methylbutane, PubChem CID: 6556, CAS Number: 78-78-4, in gas phase
IUPAC: 2,6,6-trimethylbicyclo[3.1.1]hept-2-ene, PubChem CID: 6654, CAS Number: 80-56-8, in gas phase
IUPAC: strontium, PubChem CID: 5359327, CAS Number: 7440-24-6, in particle phase, TSP
C5Hn, n={12, 10} (sum of n-pentane and cyclopentane)
Sum of n-pentane and cyclopentane, in gas phase
IUPAC: potassium-40, PubChem CID: 6328542, CAS Number: 13966-00-2
Lightning discharge type (cloud to cloud, cloud to surface)
Lightning discharge type, defined by the path of the lightning discharge: between two clouds or within the same cloud (intra-cloud) or between cloud and ground (cloud-to-ground).
IUPAC: cerium, PubChem CID: 23974, CAS Number: 7440-45-1, in particle phase, PM2.5
IUPAC: methyl propanoate, PubChem CID: 11124, CAS Number: 554-12-1, in gas phase
Major chemical components
C4H6O ((Z)-crotonaldehyde, cis-2-butenal)
IUPAC: (Z)-but-2-enal, PubChem CID: 673950, CAS Number: 15798-64-8, in gas phase
Carbonaceous fraction of particulate matter that is thermally stable in an inert atmosphere to high temperatures near 4000 K and can only be gasified by oxidation starting at temperatures above 340 degC. It is assumed to be inert and non-volatile under atmospheric conditions and insoluble in any solvent. Size range: PM1
IUPAC: (1R,4S,4aS,5S,8R,8aR)-1,2,3,4,10,10-Hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene, PubChem CID: 2087, CAS Number: 309-00-2, in wet precipitation
CH3D (monodeuterated methane, methane-d1)
IUPAC: deuteriomethane, PubChem CID: 12669, CAS Number: 676-49-3, in gas phase
The angle through which an electromagnetic wave is refracted when passing along an atmospheric path, used particularly for GNSS radio occultation observations.
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in particle phase
Walnut tree pollen
IUPAC: formonitrile, PubChem CID: 768, CAS Number: 74-90-8, in gas phase
IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in total deposition
Spectral volumetric extinction cross-section of aerosol particles.
Pine family pollen
2D field of the column burden of condensed particles in the atmosphere
C2H3F3 (1,1,1-trifluoroethane, HFC-143a)
IUPAC: 1,1,1-trifluoroethane, PubChem CID: 9868, CAS Number: 420-46-2, in gas phase
C2H2ClF3 (2-chloro-1,1,1-trifluoroethane, HCFC-133a)
IUPAC: 2-chloro-1,1,1-trifluoroethane, PubChem CID: 6408, CAS Number: 75-88-7, in gas phase
IUPAC: (E)-but-2-ene, PubChem CID: 62695, CAS Number: 107-01-7, in gas phase
IUPAC: n/a, PubChem CID: 167176, CAS Number: 14834-67-4
Number of lightning discharges per unit time in a given region (e.g. world-wide) or for a given storm system (e.g. a thunderstorm cell).
Result of cloud type classification - Accuracy expressed as inverse of number of classes, so that smaller figures correspond to better performance.
IUPAC: selenium-75, PubChem CID: 6328176, CAS Number: 14265-71-5
Ultraviolet radiation covering the range 280-315 nm.
C4H6O (but-3-en-2-one, methylvinylketone)
IUPAC: but-3-en-2-one, PubChem CID: 6570, CAS Number: 78-94-4, in gas phase
Hygroscopic particle light scattering growth factor
A scaling factor describing the particle scattering coefficient change as a function of relative humidity due to absorbing or evaporating water.
IUPAC: formate, PubChem CID: 283, CAS Number: 71-47-6, in particle phase
Hygroscopic growth factor, 50 μm equivalent
IUPAC: furan-3-carbaldehyde, PubChem CID: 10351, CAS Number: 498-60-2, in gas phase
IUPAC: 2,2-dimethylpropane, PubChem CID: 10041, CAS Number: 463-82-1, in gas phase
IUPAC: n/a, PubChem CID: 24824, CAS Number: 10028-17-8
IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, TSP
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM1
IUPAC: sulfur dioxide, PubChem CID: 1119, CAS Number: 7446 09-5, in gas phase
IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in total deposition
Earth surface short-wave bidirectional reflectance
Reflectance of the Earth surface as a function of the viewing angle and the illumination angle averaged over the range 0.4-0.7 µm.
Privet pollen
IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, PM2.5
Field of atmospheric water in the solid phase (precipitating or not) as total column.
Birch family pollen
Field of atmospheric water in the liquid phase (precipitating or not).
Mercuries pollen
CH3CCl3 (1,1,1-trichloroethane, methyl chloroform)
IUPAC: 1,1,1-trichloroethane, PubChem CID: 6278, CAS Number: 71-55-6, in gas phase
C14H10 (phenanthrene), in air and aerosol
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in aerosol
Mugwort pollen
IUPAC: tantalum-182, PubChem CID: 161013, CAS Number: 13982-00-8
Upper wind (X, Y components, horizontal)
Horizontal component of wind as a vector in an orthogonal coordinate system.
For surface observations, height of the cloud base above ground level; for aircraft observations, altitude of the cloud base above mean sea level.
IUPAC: phosphorus, PubChem CID: 5462309, CAS Number: 7723-14-0, in particle phase, PM2.5
IUPAC: n/a, PubChem CID: 166686, CAS Number: 14989-30-1, in gas phase
Selection, out of a pre-defined set of aerosol classes, that best fits an input data set (observed or modeled). The pre-defined set of aerosol classes includes specification of the particle composition, mixing state, complex refractive index, and shape as a function of particle size. The definition of aerosol type includes specification of all the classes as well as the algorithm used to choose the best fit to the input data.
IUPAC: methanedithione, PubChem CID: 6348, CAS Number: 75-15-0, in gas phase
IUPAC: uranium, PubChem CID: 23989, CAS Number: 7440-61-1, in particle phase, TSP
IUPAC: 2-hydroxyacetaldehyde, PubChem CID: 756, CAS Number: 141-46-8, in gas phase
IUPAC: cobalt-57, PubChem CID: 104851, CAS Number: 13981-50-5
IUPAC: lead-210, PubChem CID: 6328175, CAS Number: 14255-04-0
IUPAC: tert-Butyl nitrite, PubChem CID: 10906, CAS Number: 540-80-7, in gas phase
IUPAC: lanthanum, PubChem CID: 23926, CAS Number: 7439-91-0, in particle phase, TSP
IUPAC: propan-2-one, PubChem CID: 180, CAS Number: 67-64-1, in gas phase
Ångström exponent for aerosol absorption optical depth
A measure of dependence of the aerosol absorption optical depth on wavelength expressed in power law relationship.
IUPAC: fluoride, PubChem CID: 28179, CAS Number: 16984-48-8, in particle phase, TSP
u (u component of horizontal wind vector)
East-west component of the horizontal wind vector, positive value for eastward moving or west-to-east wind. This scalar quantity can be used to represent a value at given location and an instantaneous time or average over spatio-temporal extent or values as a function of spatio-temporal coordinates.
IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, PM1
CCN concentration at single supersaturation
Ragweed pollen
IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, PM10
IUPAC: 2-Methylfuran, PubChem CID: 10797, CAS Number: 534-22-5, in gas phase
Wind (surface wind direction and speed, horizontal) - deprecated
Horizontal component of wind as speed and direction.
IUPAC: chromium, PubChem CID: 23976, CAS Number: 7440-47-3, in total deposition
CBr2F2 (dibromodifluoromethane, Halon 1202)
IUPAC: dibromo(difluoro)methane, PubChem CID: 6382, CAS Number: 75-61-6, in gas phase
The amount of sky estimated to be covered by a specified cloud type (partial cloud amount), or by all cloud types (total cloud amount). In either case, the estimate is made to the nearest okta (eighth) and is reported on a scale which is essentially one of the nearest eighth, except that figures 0 and 8 on the scale signify a completely clear and cloudy sky, respectively, with consequent adjustment to the adjacent 1 and 7 okta intervals.
Linden pollen
IUPAC: plutonium-238, PubChem CID: 61709, CAS Number: 13981-16-3
IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-1, in total deposition
Particle light scattering coefficient, PM10
A measure of light attenuation due to absorption by aerosol particles expressed as the Beer-Lambert Law exponent at unit path distance. Size range: PM10
Pellitory pollen
IUPAC: antimony-124, PubChem CID: 6335510, CAS Number: 14683-10-4
IUPAC: uranium, PubChem CID: 23989, CAS Number: 7440-61-1, in particle phase, PM2.5
Density of the atmosphere.
C2Cl3F3 (1,1,2-trichloro-1,2,2-trifluoroethane, CFC-113)
IUPAC: 1,1,2-trichloro-1,2,2-trifluoroethane, PubChem CID: 6428, CAS Number: 76-13-1, in gas phase
IUPAC: cerium-141, PubChem CID: 104814, CAS Number: 13967-74-3
Luminous flux received from the background per unit solid angle and per unit area. Note: Luminous flux is a quantity derived from radiant flux by evaluating the radiation according to its action upon the International Commission on Illumination standard photometric observer.
IUPAC: 1,3,5-trimethylbenzene, PubChem CID: 7947, CAS Number: 108-67-8, in gas phase
IUPAC: niobium-95, PubChem CID: 104776, CAS Number: 13967-76-5
IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in particle phase, PM10
IUPAC: 1,2-Dichloroethane, PubChem CID: 11, CAS Number: 107-06-2, in gas phase
IUPAC: iodomethane, PubChem CID: 6328, CAS Number: 74-88-4, in gas phase
IUPAC: 3-methylbut-1-ene, PubChem CID: 11239, CAS Number: 563-45-1, in gas phase
IUPAC: ozone, PubChem CID: 24823, CAS Number: 10028-15-6, in gas phase
IUPAC: hexafluoro-λ6-sulfane, PubChem CID: 17358, CAS Number: 2551-62-4, in gas phase
IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in particle phase, PM10
IUPAC: 2,2-dimethyl-3-methylidenebicyclo[2.2.1]heptane, PubChem CID: 6616, CAS Number: 79-92-5, in gas phase
Short-wave irradiance (direction unspecified)
Flux density of short-wave radiation (direction unspecified) at a specified level within the atmosphere, including the Earth surface. Short-wave radiation includes most of the solar radiation spectrum in the atmosphere from 280 nm to 3000 nm (3 μm).
Fraction of the sky covered by clouds of a particular type or combination. It can refer to a genus, species, variety, layer, or a certain combination of clouds. Also, see 'cloud cover'.
IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, PM10
IUPAC: Methyl nitrate, PubChem CID: 11724, CAS Number: 598-58-3, in gas phase
IUPAC: cobalt, PubChem CID: 104730, CAS Number: 7440-48-4, in particle phase, TSP
IUPAC: tellurium-131, PubChem CID: 6337051, CAS Number: 14683-12-6
IUPAC: methane C-13, PubChem CID: 105026, CAS Number: 14762-74-4, in gas phase
Mass of particles per unit volume of air, size range: TSP
Cabbage family (mustards, crucifers) pollen
C2Cl2F4 (1,2-dichlorotetrafluoroethane, CFC-114)
IUPAC: 1,2-dichloro-1,1,2,2-tetrafluoroethane, PubChem CID: 6429, CAS Number: 76-14-2
Also called radiance temperature or equivalent black body temperature. The temperature of a black body emitting the spectral radiance equivalent to the observed spectral radiance at the observed frequency or wavelength.
IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in particle phase
Willow pollen
IUPAC: cerium-139, PubChem CID: 166969, CAS Number: 13982-30-4
C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in air
IUPAC: 1,1,1,2,2,3,4,5,5,5-decafluoropentane, PubChem CID: 86240, CAS Number: 138495-42-8, in gas phase
C3H2F6 (1,1,1,2,3,3-hexafluoropropane, HFC-236ea)
IUPAC: 1,1,1,2,3,3-hexafluoropropane, PubChem CID: 79009, CAS Number: 431-63-0, in gas phase
C18H12 (benz(a)anthracene), in precipitation
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in precipitation
IUPAC: actinium-228, PubChem CID: 105063, CAS Number: 14331-83-0
Flux density of diffuse short-wave solar radiation, at a specified level within the atmosphere, including the Earth surface.
Metastable (excited) state of silver-108 isotope, IUPAC: silver-108, PubChem CID: 167088, CAS Number: 14391-65-2
Transport calculations (e.g., trajectories)
IUPAC: thallium, PubChem CID: 5359464, CAS Number: 7440-28-0, in particle phase, TSP
IUPAC: methylcyclopentane, PubChem CID: 7296, CAS Number: 96-37-7, in gas phase
IUPAC: scandium-46, PubChem CID: 107673, CAS Number: 13967-63-0
IUPAC: ethane, PubChem CID: 6324, CAS Number: 74-84-0, in gas phase
A measure of light attenuation due to scattering and absorption by aerosol particles expressed as the Beer-Lambert Law exponent at unit path distance.
IUPAC: ethylbenzene, PubChem CID: 7500, CAS Number: 100-41-4, in gas phase
IUPAC: strontium-90, PubChem CID: 5486204, CAS Number: 10098-97-2
Major inorganic components, coarse
IUPAC: 1,1-Dichloroethene, PubChem CID: 6366, CAS Number: 75-35-4, in gas phase
IUPAC: butan-2-one, PubChem CID: 6569, CAS Number: 78-93-3, in gas phase
Sum of elemental and organic carbon. Includes inorganic carbon, which is operationally distributed between elemental and organic carbon. Size range: PM10
C2HClF4 (1-chloro-1,2,2,2-tetrafluoroethane, HCFC-124)
IUPAC: 2-chloro-1,1,1,2-tetrafluoroethane, PubChem CID: 17822, CAS Number: 2837-89-0, in gas phase
IUPAC: titanium, PubChem CID: 23963, CAS Number: 7440-32-6, in particle phase, TSP
The time delay of a GNSS radio signal passing along an atmospheric path from transmitter to receiver compared with the same path in vacuum.
C18H12 (benz(a)anthracene), in air and aerosol
IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in aerosol
Maple pollen
IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, TSP
IUPAC: nitric oxide, PubChem CID: 145068, CAS Number: 10102-43-9, in gas phase
Particle light absorption coefficient, PM10
Spruce pollen
Heather family pollen
IUPAC: bromide, PubChem CID: 259, CAS Number: 24959-67-9, in total deposition
3D field of super-cooled liquid water, enabling the formation of ice coating on an object.
Effective depth (thickness) of a cloud from the viewpoint of radiation propagation. Specifically, OD = exp(-K.Δz), where K is the extinction coefficient [km-1] and Δz the vertical path [km] between the base and the top of the cloud. The WMO Cloud Atlas (https://cloudatlas.wmo.int/en/optical-thickness.html) defines cloud optical thickness as 'The optical thickness of a cloud is the degree to which the cloud prevents light from passing through it.'
IUPAC: cesium-134, PubChem CID: 6335485, CAS Number: 13967-70-9
Type of clouds of genera Stratus, Stratocumulus, Cumulus, or Cumulonimbus. These occur between 0-2 km above ground [ref: WMO, International Cloud Atlas, 2017 ed.]
Concentration of dust or sand in the atmosphere
IUPAC: 1,1,2,2-tetrachloroethene, PubChem CID: 31373, CAS Number: 127-18-4, in gas phase
Particle light hemispheric backscatter coefficient
The fraction of incident radiative flux scattered into all backward angles, i.e. scattering_angle exceeding pi/2 radians.
IUPAC: (Z)-pent-2-ene, PubChem CID: 5326160, CAS Number: 627-20-3, in gas phase
Hygroscopic growth factor, total aerosol
IUPAC: ethynylbenzene, PubChem CID: 10821, CAS Number: 536-74-3, in gas phase
IUPAC: 2-methylbuta-1,3-diene, PubChem CID: 6557, CAS Number: 78-79-5, in gas phase
IUPAC: sodium-22, PubChem CID: 6328543, CAS Number: 13966-32-0
IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, PM2.5
IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM2.5
Lightning discharge direction from station
Azimuth of the lightning event with respect to the corresponding station.
IUPAC: 1-hydroxypropan-2-one, PubChem CID: 8299, CAS Number: 116-09-6, in gas phase
IUPAC: nickel, PubChem CID: 936, CAS Number: 7440-02-1, in total deposition
Emissivity of the Earth surface as a function of wavelength and viewing angle.
IUPAC: nitrite, PubChem CID: 946, CAS Number: 14797-65-0, in particle phase, TSP
Birch pollen
IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, PM10
IUPAC: (1R,4S,4aS,5S,8R,8aR)-1,2,3,4,10,10-Hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene, PubChem CID: 2087, CAS Number: 309-00-2, in gas phase
Alternaria spores
Horizontal wind speed at specified distance from reference surface
Commonly refers to the speed of horizontal wind, a ratio of the horizontal distance covered by the air to the time taken to cover that distance. This scalar quantity can be used to represent a value at a given location and an instantaneous time or average over spatio-temporal extent or values as a function of spatio-temporal coordinates.
IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in total deposition
C14H10 (phenanthrene), in total precipitation
IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in total precipitation
Grasses pollen
IUPAC: mercury-203, PubChem CID: 104771, CAS Number: 13982-78-0
IUPAC: azane, PubChem CID: 222, CAS Number: 7664-41-7, in gas phase
Long-wave irradiance (direction unspecified)
Flux density of long-wave radiation (direction unspecified) at a specified level within the atmosphere, including the Earth surface. Long-wave radiation is the radiation at wavelengths greater than 3 μm (3000 nm), including most of the spectrum emitted by sources at terrestrial temperatures.
Height of a stable layer of air with an increased temperature.
Sum of Plutonium isotopes: Pu-239 and Pu-240, IUPAC: plutonium-239, PubChem CID: 61782, CAS Number: 15117-48-3 and IUPAC: plutonium-239, PubChem CID: 61782, CAS Number: 15117-48-3
IUPAC: rubidium, PubChem CID: 5357696, CAS Number: 7440-17-7, in particle phase, PM2.5