HCl (hydrochloric acid)
type: Concept
description: IUPAC: chlorane, PubChem CID: 313, CAS Number: 7647-01-0, in gas phase
notation: 288

n-C4H10 (n-butane)
type: Concept
description: IUPAC: butane, PubChem CID: 7843, CAS Number: 106-97-8, in gas phase
notation: 501

Watervapor profile
type: Concept
notation: 256

C3H6O2 (ethyl formate)
type: Concept
description: IUPAC: ethyl formate, PubChem CID: 8025, CAS Number: 109-94-4, in gas phase
notation: 12139

V (vanadium), TSP
type: Concept
description: IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in particle phase, TSP
notation: 722

C6Hn, n={14, 12} (sum of 3-methylpentane and cyclohexane)
type: Concept
description: sum of 3-methylpentane and cyclohexane, in gas phase
notation: 477

Air temperature (at specified distance from reference surface)
type: Concept
notation: 224

Cobalt [Co-60]
type: Concept
description: IUPAC: cobalt-60, PubChem CID: 61492, CAS Number: 10198-40-0
notation: 12185

C5H10O (2-methyl-3-buten-2-ol)
type: Concept
description: IUPAC: 2-Methylbut-3-en-2-ol, PubChem CID: 8257, CAS Number: 115-18-4, in gas phase
notation: 12107

Sunshine duration
type: Concept
description: 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).
notation: 270

Pb (lead), TSP
type: Concept
description: IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in particle phase, TSP
notation: 698

C3H8 (propane)
type: Concept
description: IUPAC: propane, PubChem CID: 6334, CAS Number: 74-98-6, in gas phase
notation: 445

Particle volume size distribution
type: Concept
description: Particle volume concentration as a function of size, typically equivalent spherical radius or diameter.
notation: 12153

Total lightning flash density
type: Concept
description: 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.
notation: 12328

CH3CHO (acetaldehyde, ethanal)
type: Concept
description: IUPAC: acetaldehyde, PubChem CID: 177, CAS Number: 75-07-0, in gas phase
notation: 491

C2O4= (oxalate, ethanedioate), TSP
type: Concept
description: IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, TSP
notation: 666

Hygroscopic growth factor, 110 μm equivalent
type: Concept
notation: 413

CH2ClI (chloroiodomethane)
type: Concept
description: IUPAC: chloro(iodo)methane, PubChem CID: 11644, CAS Number: 593-71-5, in gas phase
notation: 12121

Ca++ (calcium), TSP
type: Concept
description: IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, TSP
notation: 634

C3H3N (2-propenenitrile, acrylonitrile)
type: Concept
description: IUPAC: Prop-2-enenitrile, PubChem CID: 7855, CAS Number: 107-13-1, in gas phase
notation: 12097

Ba (barium), TSP
type: Concept
description: IUPAC: barium, PubChem CID: 5355457, CAS Number: 7440-39-3, in particle phase, TSP
notation: 680

C2H3Cl2F (1,1-dichloro-2-fluoroethane, HCFC-141a)
type: Concept
description: IUPAC: 1,1-dichloro-2-fluoroethane, PubChem CID: 67936, CAS Number: 430-53-5, in gas phase
notation: 12019

Cu (copper)
type: Concept
description: IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in total deposition
notation: 602

Downward spectral radiance
type: Concept
description: Downward radiant power per area unit, per solid angle, and per wavelength or wavenumber interval.
notation: 12310

Cloud hydrometeor concentration
type: Concept
description: Number of cloud hydrometeors (or cloud particles) per unit volume. Cloud hydrometeors refer to liquid and/or ice cloud particles.
notation: 182

UV Erythemal radiation
type: Concept
description: Radiation effective in causing actinic erythema
notation: 357

Taxus
type: Concept
description: Yew pollen
notation: 12065

C2H5COO- (propionate)
type: Concept
description: IUPAC: propanoate, PubChem CID: 104745, CAS Number: 72-03-7, in total deposition
notation: 578

Aerosol optical depth, TSP
type: Concept
description: 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].
notation: 325

Castanea
type: Concept
description: Sweet chestnut pollen
notation: 12033

Tellurium [Te-132]
type: Concept
description: IUPAC: tellurium-132, PubChem CID: 6336614, CAS Number: 14234-28-7
notation: 12208

Particle number size distribution, TSP
type: Concept
description: Particle number concentration as a function of size, typically equivalent spherical radius or diameter. Size range: PM10
notation: 371

Mg++ (magnesium)
type: Concept
description: IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in total deposition
notation: 546

Total lightning density
type: Concept
notation: 12001

CCl2F2 (dichlorodifluoromethane, CFC-12)
type: Concept
description: IUPAC: dichloro(difluoro)methane, PubChem CID: 6391, CAS Number: 75-71-8, in gas phase
notation: 592

Lanthanum [La-140]
type: Concept
description: IUPAC: lanthanum-140, PubChem CID: 104882, CAS Number: 13981-28-7
notation: 12222

C4H5F5 (1,1,1,3,3-pentafluorobutane, HFC-365mfc)
type: Concept
description: IUPAC: 1,1,1,3,3-pentafluorobutane, PubChem CID: 67884, CAS Number: 406-58-6, in gas phase
notation: 560

Technetium [Tc-99m]
type: Concept
description: Metastable (excited) state of technetium-99 isotope, IUPAC: technetium-99, PubChem CID: 26476, CAS Number: 14133-76-7
notation: 12198

Hg (mercury), TSP
type: Concept
description: IUPAC: mercury, PubChem CID: 23931, CAS Number: 7439-97-6, in particle phase, TSP
notation: 703

CHCl3 (trichloromethane, chloroform)
type: Concept
description: IUPAC: chloroform, PubChem CID: 6212, CAS Number: 67-66-3, in gas phase
notation: 283

C5H10 (sum of 1-pentene and 2-methyl-2-butene)
type: Concept
notation: 458

Air Temperature
type: Concept
description: Temperature of an air parcel. Note, temperature is a fundamental property of matter as defined in the SI system.
notation: 12166

H2 (hydrogen molecule)
type: Concept
description: IUPAC: molecular hydrogen, PubChem CID: 783, CAS Number: 1333-74-0, in gas phase
notation: 205

Humidity (at specified distance from reference surface)
type: Concept
notation: 251

Ba (barium), PM2.5
type: Concept
description: IUPAC: barium, PubChem CID: 5355457, CAS Number: 7440-39-3, in particle phase, PM2.5
notation: 679

C10H16 (3-carene)
type: Concept
description: IUPAC: 3,7,7-trimethylbicyclo[4.1.0]hept-3-ene, PubChem CID: 26049, CAS Number: 13466-78-9, in gas phase
notation: 12134

Upward spectral radiance
type: Concept
description: Upward radiant power per area unit, per solid angle, and per wavelength or wavenumber interval.
notation: 12309

C6H14 (2-methylpentane)
type: Concept
description: IUPAC: 2-methylpentane, PubChem CID: 7892, CAS Number: 107-83-5, in gas phase
notation: 472

Manganese [Mn-56]
type: Concept
description: IUPAC: manganese-56, PubChem CID: 114694, CAS Number: 14681-52-8
notation: 12180

NH4+ (ammonium), TSP
type: Concept
description: IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, TSP
notation: 647

C3H7NO3 (isopropyl nitrate)
type: Concept
description: IUPAC: Propan-2-yl nitrate, PubChem CID: 15575, CAS Number: 1712-64-7, in gas phase
notation: 12102

Cu (copper), TSP
type: Concept
description: IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in particle phase, TSP
notation: 693

C3H4O (prop-2-enal, acrolein)
type: Concept
description: IUPAC: prop-2-enal, PubChem CID: 7847, CAS Number: 107-02-8, in gas phase
notation: 440

Cl- (chloride), PM10
type: Concept
description: IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM10
notation: 615

CO2 (carbon dioxide, C-13)
type: Concept
description: IUPAC: n/a, PubChem CID: 10129882, CAS Number: 1111-72-4, in gas phase
notation: 195

Cedrus
type: Concept
description: Cedar family pollen
notation: 12078

Other chemical components, fine
type: Concept
description: Other chemical components, fine
notation: 661

Radar backscatter coefficient
type: Concept
description: Normalised radar cross section (NRCS) backscatter coefficient, also called sigma-0 ('sigma-nought'). The normalised measure of the radar return, measured in dB.
notation: 12299

C14H10 (anthracene), in air
type: Concept
description: IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in gas phase
notation: 338

Olea
type: Concept
description: Olive pollen
notation: 12046

C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, gamma-lindane, gamma-HCH), in air
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in gas phase
notation: 384

C3H8O (1-propanol)
type: Concept
description: IUPAC: Propan-1-ol, PubChem CID: 1031, CAS Number: 71-23-8, in gas phase
notation: 12092

C3HF7 (1,1,1,2,3,3,3-Heptafluoropropane, HFC-227ea)
type: Concept
description: IUPAC: 1,1,1,2,3,3,3-heptafluoropropane, PubChem CID: 67940, CAS Number: 431-89-0, in gas phase
notation: 559

Plantago
type: Concept
description: Plantain pollen
notation: 12060

Uranium [U-234]
type: Concept
description: IUPAC: uranium-234, PubChem CID: 61704, CAS Number: 13966-29-5
notation: 12235

Downward short-wave irradiance
type: Concept
description: 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.]
notation: 573

Light backscattering coefficient, PM10
type: Concept
notation: 320

Indium [In-111]
type: Concept
description: IUPAC: indium-111, PubChem CID: 5462099, CAS Number: 15750-15-9
notation: 12203

I- (iodide)
type: Concept
description: IUPAC: iodide, PubChem CID: 30165, CAS Number: 20461-54-5, in total deposition
notation: 541

Th (thorium), TSP
type: Concept
description: IUPAC: thorium, PubChem CID: 23960, CAS Number: 7440-29-1, in particle phase, TSP
notation: 716

Hydrogen ion (H+) or pH
type: Concept
notation: 296

Pressure tendency
type: Concept
description: 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.
notation: 218

Manganese [Mn-53]
type: Concept
description: IUPAC: manganese-53, PubChem CID: 167227, CAS Number: 14999-33-8
notation: 12179

Vertical ozone profile
type: Concept
notation: 264

C3H4 (propyne)
type: Concept
description: IUPAC: prop-1-yne, PubChem CID: 6335, CAS Number: 74-99-7, in gas phase
notation: 439

Ångström exponent for particle light extinction
type: Concept
description: A measure of dependence of the particle light extinction coefficient on wavelength expressed in power law relationship.
notation: 12147

C8H10 (o-xylene)
type: Concept
description: IUPAC: 1,2-xylene, PubChem CID: 7237, CAS Number: 95-47-6, in gas phase
notation: 485

Yttrium [Y-88]
type: Concept
description: IUPAC: yttrium-88, PubChem CID: 105173, CAS Number: 13982-36-0
notation: 12193

C2H2Cl2 ((E)-1,2-dichloroethene, trans-1,2-dichloroethene)
type: Concept
description: IUPAC: (E)-1,2-dichloroethene, PubChem CID: 638186, CAS Number: 156-60-5, in gas phase
notation: 12115

C5H10 (1-pentene)
type: Concept
description: IUPAC: pent-1-ene, PubChem CID: 8004, CAS Number: 109-67-1, in gas phase
notation: 453

Particle effective diameter
type: Concept
description: The area weighted mean diameter of the aerosol particles.
notation: 12161

Al (aluminium), TSP
type: Concept
description: IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in particle phase, TSP
notation: 674

CF4 (tetrafluoromethane, carbon tetrafluoride, perfluoromethane, PFC-14)
type: Concept
description: IUPAC: tetrafluoromethane, PubChem CID: 6393, CAS Number: 75-73-0, in gas phase
notation: 421

Delay Doppler map
type: Concept
description: A 2D array of backscatter coefficients as a function of Doppler shift and signal delay, derived from GNSS reflectometry.
notation: 12304

Brassica
type: Concept
description: Brassica pollen
notation: 12059

Na+ (sodium), PM2.5
type: Concept
description: IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, PM2.5
notation: 642

NOx
type: Concept
notation: 397

Light backscattering coefficient, PM1
type: Concept
notation: 319

Pinus
type: Concept
description: Pine pollen
notation: 12027

Particle mass concentration, PM1
type: Concept
description: Mass of particles per unit volume of air, size range: PM1
notation: 365

Silene
type: Concept
description: Melandrium pollen
notation: 12073

Attenuated backscatter
type: Concept
description: 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.
notation: 12248

CBrF3 (bromotrifluoromethane, Halon 1301)
type: Concept
description: IUPAC: bromo(trifluoro)methane, PubChem CID: 6384, CAS Number: 75-63-8, in gas phase
notation: 333

Total Amaranthaceae
type: Concept
description: Amaranth family pollen
notation: 12041

Optical depth within a cloud layer
type: Concept
description: 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.
notation: 508

Caesium [Cs-137]
type: Concept
description: IUPAC: cesium-137, PubChem CID: 5486527, CAS Number: 10045-97-3
notation: 12216

C2H2F4 (1,1,1,2-tetrafluoroethane, HFC-134a)
type: Concept
description: IUPAC: 1,1,1,2-tetrafluoroethane, PubChem CID: 13129, CAS Number: 811-97-2, in gas phase
notation: 554

Aerosol volcanic ash (Total column)
type: Concept
description: Field of total column mass of volcanic ash
notation: 729

Hydrometeor radius
type: Concept
notation: 522

Lead [Pb-212]
type: Concept
description: IUPAC: lead-212, PubChem CID: 6335491, CAS Number: 15092-94-1
notation: 12230

CH2Br2 (dibromomethane)
type: Concept
description: IUPAC: dibromomethane, PubChem CID: 3024, CAS Number: 74-95-3, in gas phase
notation: 277

i-C4H8 (2-methylpropene, iso-butene)
type: Concept
description: IUPAC: 2-methylprop-1-ene, PubChem CID: 8255, CAS Number: 115-11-7, in gas phase
notation: 498

C10H16 (tricyclene)
type: Concept
description: IUPAC: 1,7,7-trimethyltricyclo[2.2.1.02,6]heptane, PubChem CID: 79035, CAS Number: 508-32-7, in gas phase
notation: 12128

Sr (strontium), PM2.5
type: Concept
description: IUPAC: strontium, PubChem CID: 5359327, CAS Number: 7440-24-6, in particle phase, PM2.5
notation: 711

ROOH
type: Concept
notation: 291

C5Hn, n=10 (sum of 3-methyl-1-butene and cyclopentene)
type: Concept
description: Sum of 3-methyl-1-butene and cyclopentane, in gas phase
notation: 466

Occurrence of precipitation during last period (yes/no)
type: Concept
notation: 213

Chlorine [Cl-38]
type: Concept
description: IUPAC: n/a, PubChem CID: 167013, CAS Number: 14158-34-0
notation: 12174

Cd (cadmium), TSP
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, TSP
notation: 687

C2H2 (ethyne, acetylene)
type: Concept
description: IUPAC: acetylene, PubChem CID: 6326, CAS Number: 74-86-2, in gas phase
notation: 434

C4H8O2 (ethyl acetate)
type: Concept
description: IUPAC: ethyl acetate, PubChem CID: 8857, CAS Number: 141-78-6, in gas phase
notation: 12142

Zn (zinc)
type: Concept
description: IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in total deposition
notation: 609

C7H16 (sum of methylhexanes)
type: Concept
notation: 480

Sum of HNO3 (nitric acid) and NO3- (nitrate)
type: Concept
description: Sum of HNO3 (nitric acid) and NO3- (nitrate)
notation: 655

C4H6O ((E)-crotonaldehyde, trans-2-butenal)
type: Concept
description: IUPAC: (2E)-but-2-enal, PubChem CID: 447466, CAS Number: 123-73-9, in gas phase
notation: 12110

Elemental carbon, PM10
type: Concept
description: 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
notation: 623

C12H8Cl6 (aldrin), in total precipitation
type: Concept
description: 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
notation: 378

NF3 (nitrogen trifluoride)
type: Concept
description: IUPAC: nitrogen trifluoride, PubChem CID: 24553, CAS Number: 7783-54-2, in gas phase
notation: 12086

Cd (cadmium)
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in total deposition
notation: 599

C18H12 (benz(a)anthracene), PM10
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in particle phase, PM10
notation: 346

Zea mays
type: Concept
description: Maize pollen
notation: 12054

bismuth [Bi-213]
type: Concept
description: IUPAC: bismuth-213, PubChem CID: 6337093, CAS Number: 15776-20-2
notation: 12229

ClONO2 (chlorine nitrate)
type: Concept
description: IUPAC: chloro nitrate, PubChem CID: 114934, CAS Number: 14545-72-3, in gas phase
notation: 392

Upward long-wave irradiance
type: Concept
description: 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.
notation: 567

Aerosol Absorption Optical Depth
type: Concept
description: 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]
notation: 314

Total pollen
type: Concept
description: All pollen taxa
notation: 12022

C2H3ClF2 (1-chloro-1,1-difluoroethane, HCFC-142b)
type: Concept
description: IUPAC: 1-chloro-1,1-difluoroethane, PubChem CID: 6388, CAS Number: 75-68-3, in gas phase
notation: 535

C2H2Cl2F2 (1,2-dichloro-1,1-difluoroethane, HCFC-132b)
type: Concept
description: IUPAC: 1,2-dichloro-1,1-difluoroethane, PubChem CID: 15442, CAS Number: 1649-08-7, in gas phase
notation: 12243

n-C7H16 (n-heptane)
type: Concept
description: IUPAC: heptane, PubChem CID: 8900, CAS Number: 142-82-5, in gas phase
notation: 503

Iodine [I-132], elementary
type: Concept
description: IUPAC: n/a, PubChem CID: 104966, CAS Number: 14683-16-0
notation: 12211

Lightning discharge polarity
type: Concept
description: Polarity of the charge effectively lowered to ground during a lightning discharge.
notation: 258

Zn (zinc), TSP
type: Concept
description: IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in particle phase, TSP
notation: 724

Integrated air samples
type: Concept
notation: 44

C6Hn, n={14, 12} (sum of 2,3-dimethylbutane and methylcyclopentane)
type: Concept
description: sum of 2,3-dimethylbutane and methylcyclopentane, in gas phase
notation: 479

Gallium [Ga-67]
type: Concept
description: IUPAC: gallium-67, PubChem CID: 5464084, CAS Number: 14119-09-6
notation: 12187

Extreme temperature (min, max) (at specified distance from reference surface)
type: Concept
notation: 226

C8H18 (2,2,4-trimethylpentane)
type: Concept
description: IUPAC: 2,2,4-Trimethylpentane, PubChem CID: 10907, CAS Number: 540-84-1, in gas phase
notation: 12109

C4H6O (2-methylprop-2-enal, methacrolein)
type: Concept
description: IUPAC: 2-methylprop-2-enal, PubChem CID: 6562, CAS Number: 78-85-3, in gas phase
notation: 447

Hygroscopic particle size growth factor
type: Concept
description: A scaling factor describing the particle equivalent spherical size change as a function of relative humidity due to absorbing or evaporating water.
notation: 12155

CH3OH (methanol)
type: Concept
description: IUPAC: methanol, PubChem CID: 887, CAS Number: 67-56-1, in gas phase
notation: 493

CH3O3S- (methanesulfonate), TSP
type: Concept
description: IUPAC: methanesulfonate, PubChem CID: 85257, CAS Number: 16053-58-0, in particle phase, TSP
notation: 668

Hygroscopic growth factor, 35 μm equivalent
type: Concept
notation: 415

C5H4O2 (furfural)
type: Concept
description: IUPAC: furan-2-carbaldehyde, PubChem CID: 7362, CAS Number: 98-01-1, in gas phase
notation: 12123

C5H12 & C4H8 (sum of 2,2-dimethylpropane & c-2-butene)
type: Concept
notation: 461

Mg++ (magnesium), PM2.5
type: Concept
description: IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, PM2.5
notation: 636

C4H5N (2-methyl-2-propenenitrile, methylacrylonitrile)
type: Concept
description: IUPAC: 2-Methylprop-2-enenitrile, PubChem CID: 31368, CAS Number: 126-98-7, in gas phase
notation: 12099

Bi (bismuth), TSP
type: Concept
description: IUPAC: bismuth, PubChem CID: 5359367, CAS Number: 7440-69-9, in particle phase, TSP
notation: 682

Pb (lead)
type: Concept
description: IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in total deposition
notation: 604

Solar total irradiance
type: Concept
description: Spectrally integrated flux density of radiation received from the sun at the top of the atmosphere. Also called 'Total solar irradiance (TSI)'.
notation: 12312

UV Spectral radiation
type: Concept
description: UV radiation measured at a higher spectral resolution (e.g. 1 nm) than multiband UV radiation
notation: 359

Ilex
type: Concept
description: Holly pollen
notation: 12067

NO3- (nitrate), PM10
type: Concept
description: IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, PM10
notation: 650

Cloud ice
type: Concept
description: Atmospheric water in the solid phase (precipitating or not).
notation: 327

Quercus
type: Concept
description: Oak pollen
notation: 12035

Cloud liquid water (CLW)
type: Concept
description: Atmospheric water in the liquid phase (precipitating or not).
notation: 373

Liquidambar
type: Concept
description: Sweetgum pollen
notation: 12081

Na+ (sodium)
type: Concept
description: IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in total deposition
notation: 548

CCl4 (tetrachloromethane, carbon tetrachloride)
type: Concept
description: IUPAC: tetrachloromethane, PubChem CID: 5943, CAS Number: 56-23-5, in gas phase
notation: 594

C14H10 (phenanthrene), in air
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in gas phase
notation: 341

Europium [Eu-152]
type: Concept
description: IUPAC: europium-152, PubChem CID: 104907, CAS Number: 14683-23-9
notation: 12224

CHF3 (trifluoromethane, HFC-23)
type: Concept
description: IUPAC: fluoroform, PubChem CID: 6373, CAS Number: 75-46-7, in gas phase
notation: 562

State of ground
type: Concept
notation: 57

Ni (nickel), TSP
type: Concept
description: IUPAC: nickel, PubChem CID: 935, CAS Number: 7440-02-0, in particle phase, TSP
notation: 705

COF2 (difluoromethanal, carbonyl fluoride)
type: Concept
description: IUPAC: carbonyl difluoride, PubChem CID: 9623, CAS Number: 353-50-4, in gas phase
notation: 285

HDO (as a chemical species)
type: Concept
description: IUPAC: n/a, PubChem CID: 139859, CAS Number: 14940-63-7, in gas phase
notation: 207

Height of the top of the PBL
type: Concept
description: Height of the surface above ground separating the planetary boundary layer (PBL) from the free atmosphere.
notation: 12168

Mixing ratio
type: Concept
description: 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.
notation: 253

COS (OCS, carbon oxide sulfide, carbonyl sulfide)
type: Concept
description: IUPAC: carbonyl sulfide, PubChem CID: 10039, CAS Number: 463-58-1, in gas phase
notation: 428

C2H4O2 (methyl formate)
type: Concept
description: IUPAC: methyl formate, PubChem CID: 7865, CAS Number: 107-31-3, in gas phase
notation: 12136

C6H14 (n-hexane)
type: Concept
description: IUPAC: hexane, PubChem CID: 8058, CAS Number: 110-54-3, in gas phase
notation: 474

Cobalt [Co-56]
type: Concept
description: IUPAC: cobalt-56, PubChem CID: 166998, CAS Number: 14093-03-9
notation: 12182

Krypton [Kr-85]
type: Concept
description: IUPAC: krypton-85, PubChem CID: 104816, CAS Number: 13983-27-2
notation: 221

NH4NO3 (ammonium nitrate), PM1
type: Concept
description: IUPAC: ammonium nitrate, PubChem CID: 22985, CAS Number: 6484-52-2, in particle phase, PM1
notation: 649

C4H9NO3 (isobutyl nitrate)
type: Concept
description: IUPAC: 2-Methylpropyl nitrate, PubChem CID: 10974, CAS Number: 928-45-0, in gas phase
notation: 12104

La (lanthanum), PM2.5
type: Concept
description: IUPAC: lanthanum, PubChem CID: 23926, CAS Number: 7439-91-0, in particle phase, PM2.5
notation: 695

C3H6 (propene)
type: Concept
description: IUPAC: prop-1-ene, PubChem CID: 8252, CAS Number: 115-07-1, in gas phase
notation: 442

Ångström exponent for aerosol optical depth
type: Concept
description: A measure of dependence of the aerosol optical depth on wavelength expressed in power law relationship.
notation: 12150

Cl- (chloride), TSP
type: Concept
description: IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, TSP
notation: 617

C2H3O2- (CH3COO-, acetate)
type: Concept
description: IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-0, in particle phase
notation: 663

Total Asteraceae
type: Concept
description: Aster family pollen
notation: 12048

C4H4O (furan)
type: Concept
description: IUPAC: Furan, PubChem CID: 8029, CAS Number: 110-00-9, in gas phase
notation: 12094

Cl3CCF3 (1,1,1-trichloro-2,2,2-trifluoroethane, CFC-113a)
type: Concept
description: IUPAC: 1,1,1-trichloro-2,2,2-trifluoroethane, PubChem CID: 9635, CAS Number: 354-58-5, in gas phase
notation: 12016

Rumex
type: Concept
description: Rumex (dock, sorrel) pollen
notation: 12062

Strong acids
type: Concept
notation: 529

Uranium [U-238]
type: Concept
description: IUPAC: uranium-238, PubChem CID: n/a, CAS Number: n/a
notation: 12237

Particle light scattering coefficient, PM1
type: Concept
description: 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
notation: 322

Platanus
type: Concept
description: Plane tree pollen
notation: 12030

Antimony [Sb-122]
type: Concept
description: IUPAC: antimony-122, PubChem CID: 6335836, CAS Number: 14374-79-9
notation: 12205

SO4= (sulfate), corrected
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in total deposition
notation: 543

Relative attenuated backscatter
type: Concept
description: 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.
notation: 12251

Sn (tin), TSP
type: Concept
description: IUPAC: tin, PubChem CID: 5352426, CAS Number: 7440-31-5, in particle phase, TSP
notation: 718

Present weather
type: Concept
description: 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.]
notation: 266

Ångström exponent for particle light absorption
type: Concept
description: A measure of dependence of the particle light absorption coefficient on wavelength expressed in power law relationship.
notation: 12149

C9H12 (1,2,4-trimethylbenzene)
type: Concept
description: IUPAC: 1,2,4-trimethylbenzene, PubChem CID: 7247, CAS Number: 95-36-3, in gas phase
notation: 487

Zirconium [Zr-95]
type: Concept
description: IUPAC: zirconium-95, PubChem CID: 91573, CAS Number: 13967-71-0
notation: 12195

C2H4Cl2 (1,1-dichloroethane)
type: Concept
description: IUPAC: 1,1-Dichloroethane, PubChem CID: 6365, CAS Number: 75-34-3, in gas phase
notation: 12117

Li (lithium), TSP
type: Concept
description: IUPAC: lithium, PubChem CID: 3028194, CAS Number: 7439-93-2, in particle phase, TSP
notation: 700

CH3Cl (chloromethane)
type: Concept
description: IUPAC: chloromethane, PubChem CID: 6327, CAS Number: 74-87-3, in gas phase
notation: 280

C5H10 (2-methyl-2-butene)
type: Concept
description: IUPAC: 2-methylbut-2-ene, PubChem CID: 10553, CAS Number: 513-35-9, in gas phase
notation: 455

Mixed layer height
type: Concept
description: Height above the surface to which atmospheric properties (wind speed, etc) or atmospheric constituents (aerosol, gases) are dispersed by turbulent vertical mixing
notation: 12163

Sb (antimony), TSP
type: Concept
description: IUPAC: antimony, PubChem CID: 5354495, CAS Number: 7440-36-0, in particle phase, TSP
notation: 676

C10H16 (myrcene)
type: Concept
description: IUPAC: 7-methyl-3-methylideneocta-1, PubChem CID: 31253, CAS Number: 123-35-3, in gas phase
notation: 12131

Net short-wave irradiance
type: Concept
description: 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.
notation: 12306

NH3 (ammonia), PM2.5
type: Concept
description: IUPAC: azane, PubChem CID: 222, CAS Number: 7664-41-7, in particle phase, PM2.5
notation: 644

Cr (chromium), TSP
type: Concept
description: IUPAC: chromium, PubChem CID: 23976, CAS Number: 7440-47-3, in particle phase, TSP
notation: 690

Total Arecaceae
type: Concept
description: Palm family pollen
notation: 12029

C3H2F6 (1,1,1,3,3,3-hexafluoropropane, HFC-236fa)
type: Concept
description: IUPAC: 1,1,1,3,3,3-hexafluoropropane, PubChem CID: 12722, CAS Number: 690-39-1, in gas phase
notation: 12320

CH4 (methane)
type: Concept
description: IUPAC: methane, PubChem CID: 297, CAS Number: 74-82-8, in gas phase
notation: 192

Particle mass concentration (size fractionated)
type: Concept
description: Mass of particles per unit volume of air, size fractionated
notation: 367

Total Umbelliferae
type: Concept
description: Celery, carrot or parsley family pollen
notation: 12075

Spectral radiance
type: Concept
description: 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.
notation: 12296

C14H10 (anthracene), PM10
type: Concept
description: IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in particle phase, PM10
notation: 335

Populus
type: Concept
description: Poplar pollen
notation: 12043

barium [Ba-140]
type: Concept
description: IUPAC: barium-140, PubChem CID: 6335490, CAS Number: 14798-08-4
notation: 12218

C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in aerosol
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in particle phase
notation: 381

C2HF5 (pentafluoroethane, HFC-125)
type: Concept
description: IUPAC: 1,1,1,2,2-pentafluoroethane, PubChem CID: 9633, CAS Number: 354-33-6, in gas phase
notation: 556

Lithometeor type
type: Concept
notation: 524

Radium [Ra-226]
type: Concept
description: IUPAC: radium-226, PubChem CID: 9877911, CAS Number: 13982-63-3
notation: 12232

CH3Br (bromomethane)
type: Concept
description: IUPAC: bromomethane, PubChem CID: 6323, CAS Number: 74-83-9, in gas phase
notation: 279

NO2- (nitrite)
type: Concept
description: IUPAC: nitrite, PubChem CID: 946, CAS Number: 14797-65-0, in total deposition
notation: 570

Ruthenium [Ru-106]
type: Concept
description: IUPAC: ruthenium-106, PubChem CID: 26359, CAS Number: 13967-48-1
notation: 12200

Tl (thallium), PM2.5
type: Concept
description: IUPAC: thallium, PubChem CID: 5359464, CAS Number: 7440-28-0, in particle phase, PM2.5
notation: 713

C6H12 (cyclohexane)
type: Concept
description: IUPAC: cyclohexane, PubChem CID: 8078, CAS Number: 110-82-7, in gas phase
notation: 468

Potassium [K-42]
type: Concept
description: IUPAC: potassium-42, PubChem CID: 11607897, CAS Number: 14378-21-3
notation: 12176

Type of precipitation
type: Concept
notation: 215

Ce (cerium), TSP
type: Concept
description: IUPAC: cerium, PubChem CID: 23974, CAS Number: 7440-45-1, in particle phase, TSP
notation: 689

C2H4 (ethene)
type: Concept
description: IUPAC: ethene, PubChem CID: 6325, CAS Number: 74-85-1, in gas phase
notation: 436

C8H10 (p-xylene)
type: Concept
description: IUPAC: 1,4-xylene, PubChem CID: 7809, CAS Number: 106-42-3, in gas phase
notation: 12144

C7H8 (toluene)
type: Concept
description: IUPAC: toluene, PubChem CID: 1140, CAS Number: 108-88-3, in gas phase
notation: 482

Strontium [Sr-89]
type: Concept
description: IUPAC: strontium-89, PubChem CID: 5388880, CAS Number: 14158-27-1
notation: 12190

Major inorganic components, TSP
type: Concept
description: Major inorganic components, TSP
notation: 657

C4H6O (crotonaldehyde, 2-butenal)
type: Concept
description: IUPAC: But-2-enal, PubChem CID: 20138, CAS Number: 4170-30-3, in gas phase
notation: 12112

C4H8 (sum of butenes)
type: Concept
notation: 450

Elemental carbon, PM2.5
type: Concept
description: 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
notation: 625

Carbonaceous-organic material, fine
type: Concept
notation: 671

CClF3 (chlorotrifluoromethane, CFC-13)
type: Concept
description: IUPAC: chloro(trifluoro)methane, PubChem CID: 6392, CAS Number: 75-72-9, in gas phase
notation: 12088

Refractivity
type: Concept
description: The refractive index (of air) minus one. Particularly used for GNSS radio occultation observations.
notation: 12301

C18H12 (benz(a)anthracene), in air
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in gas phase
notation: 348

Ulmus
type: Concept
description: Elm pollen
notation: 12056

HNO3 (nitric acid)
type: Concept
description: IUPAC: nitric acid, PubChem CID: 944, CAS Number: 7697-37-2, in gas phase
notation: 394

NO3- (nitrate)
type: Concept
description: IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in total deposition
notation: 569

Particle light absorption coefficient, PM1
type: Concept
description: 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
notation: 316

Abies
type: Concept
description: Fir pollen
notation: 12024

Particle effective radius
type: Concept
description: The area weighted mean radius of the aerosol particles.
notation: 362

Total Cyperaceae
type: Concept
description: Sedge family pollen
notation: 12070

CHClF2 (chlorodifluoromethane, HCFC-22)
type: Concept
description: IUPAC: chloro(difluoro)methane, PubChem CID: 6372, CAS Number: 75-45-6, in gas phase
notation: 537

C3H2F6 (1,1,1,3,3,3-hexafluoropropane, HFC-236fa)
type: Concept
description: IUPAC: 1,1,1,3,3,3-hexafluoropropane, PubChem CID: 12722, CAS Number: 690-39-1, in gas phase
notation: 12245

Freezing level height in clouds
type: Concept
description: Height of the atmospheric layer in cloud where liquid-solid states transform into each other
notation: 330

t-C5H10 (trans-2-pentene)
type: Concept
description: IUPAC: (E)-pent-2-ene, PubChem CID: 5326161, CAS Number: 109-68-2, in gas phase
notation: 505

Xenon [Xe-133]
type: Concept
description: IUPAC: xenon-133, PubChem CID: 66376, CAS Number: 14932-42-4
notation: 12213

Type of high clouds
type: Concept
description: 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.]
notation: 551

Strontium [Sr-85]
type: Concept
description: IUPAC: strontium-85, PubChem CID: 5464271, CAS Number: 13967-73-2
notation: 12189

BrO (bromine monoxide)
type: Concept
description: IUPAC: n/a, PubChem CID: 5460627, CAS Number: 15656-19-6, in gas phase
notation: 274

C4H8 (1-butene)
type: Concept
description: IUPAC: but-1-ene, PubChem CID: 7844, CAS Number: 106-98-9, in gas phase
notation: 449

Hygroscopic particle light extinction growth factor
type: Concept
description: A scaling factor describing the particle extinction coefficient change as a function of relative humidity due to absorbing or evaporating water.
notation: 12157

c-C4H8 (cis-2-butene)
type: Concept
description: IUPAC: (Z)-but-2-ene, PubChem CID: 5287573, CAS Number: 590-18-1, in gas phase
notation: 495

Hygroscopic growth factor, 75 μm equivalent
type: Concept
notation: 417

C8H8 (styrene)
type: Concept
description: IUPAC: styrene, PubChem CID: 7501, CAS Number: 100-42-5, in gas phase
notation: 12125

C5H14 (2,3-dimethylbutane)
type: Concept
description: IUPAC: 2,3-dimethylbutane, PubChem CID: 6589, CAS Number: 79-29-8, in gas phase
notation: 463

Carbon [C-14]
type: Concept
description: IUPAC: n/a, PubChem CID: 26873, CAS Number: 14762-75-5
notation: 12171

Amount of precipitation
type: Concept
description: 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'.
notation: 210

K+ (potassium), PM10
type: Concept
description: IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, PM10
notation: 638

Cd (cadmium), PM10
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM10
notation: 684

Lightning detection (time and location)
type: Concept
description: 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.
notation: 431

Hg (mercury)
type: Concept
description: IUPAC: mercury, PubChem CID: 23931, CAS Number: 7439-97-6, in total deposition
notation: 606

Earth surface spectral bidirectional reflectance
type: Concept
description: 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)].
notation: 12314

Melting layer depth in clouds
type: Concept
description: Depth of the atmospheric layer in cloud where liquid-solid states transform into each other.
notation: 186

Total Juncaceae
type: Concept
description: Rush family pollen
notation: 12069

NO3- (nitrate), TSP
type: Concept
description: IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, TSP
notation: 652

Cloud ice effective radius
type: Concept
description: The area weighted mean radius of ice particles, assimilated to spheres of the same volume.
notation: 329

Alnus
type: Concept
description: Alder pollen
notation: 12037

SO4= (sulfate), TSP
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, TSP
notation: 620

C12H8Cl6 (aldrin), in aerosol
type: Concept
description: 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
notation: 375

Total Moraceae
type: Concept
description: Mulberry family pollen
notation: 12083

Horizontal wind direction at specified distance from reference surface
type: Concept
description: 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.
notation: 12005

C14H10 (phenanthrene), in wet deposition
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in wet deposition
notation: 343

Solidago
type: Concept
description: Solidago (goldenrod) pollen
notation: 12051

Iridium [Ir-192]
type: Concept
description: IUPAC: iridium-192, PubChem CID: 66373, CAS Number: 14694-69-0
notation: 12226

Cloud top height
type: Concept
description: Height of the top of the cloud (highest cloud in case of multi-layer clouds) above mean sea level.
notation: 532

Americium [Am-241]
type: Concept
description: IUPAC: americium-241, PubChem CID: 104726, CAS Number: 14596-10-2
notation: 12240

P (phosphorous), TSP
type: Concept
description: IUPAC: phosphorus, PubChem CID: 5462309, CAS Number: 7723-14-0, in particle phase, TSP
notation: 707

H2O2 (hydrogen peroxide)
type: Concept
description: IUPAC: hydrogen peroxide, PubChem CID: 784, CAS Number: 7722-84-1, in gas phase
notation: 287

i-C7H16 (2-methylhexane, isoheptane)
type: Concept
description: IUPAC: 2-methylhexane, PubChem CID: 11582, CAS Number: 591-76-4, in gas phase
notation: 500

Water vapour pressure
type: Concept
description: Partial pressure of water vapour in an air parcel
notation: 255

C3H6O2 (methyl acetate)
type: Concept
description: IUPAC: methyl acetate, PubChem CID: 6584, CAS Number: 79-20-9, in gas phase
notation: 12138

V (vanadium), PM2.5
type: Concept
description: IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in particle phase, PM2.5
notation: 721

C6H6 (benzene)
type: Concept
description: IUPAC: benzene, PubChem CID: 241, CAS Number: 71-43-2, in gas phase
notation: 476

Cobalt [Co-58]
type: Concept
description: IUPAC: cobalt-58, PubChem CID: 104844, CAS Number: 13981-38-9
notation: 12184

Radon [Rn-222]
type: Concept
description: IUPAC: radon-222, PubChem CID: 61773, CAS Number: 14859-67-7
notation: 223

C4H9NO3 (2-butyl nitrate, sec-butyl nitrate)
type: Concept
description: IUPAC: Butan-2-yl nitrite, PubChem CID: 13544, CAS Number: 924-43-6, in gas phase
notation: 12106

Pb (lead), PM10
type: Concept
description: IUPAC: lead, PubChem CID: 5352425, CAS Number: 7439-92-1, in particle phase, PM10
notation: 697

C3H6O (propanal)
type: Concept
description: IUPAC: propanal, PubChem CID: 527, CAS Number: 123-38-6, in gas phase
notation: 444

Particle surface area size distribution
type: Concept
description: Particle surface area concentration as a function of size, typically equivalent spherical radius or diameter.
notation: 12152

SO4= (sulfate), corrected
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase
notation: 619

v (v component of horizontal wind vector)
type: Concept
description: 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.
notation: 12327

CH3CH2OH (ethanol)
type: Concept
description: IUPAC: ethanol, PubChem CID: 702, CAS Number: 64-17-5, in gas phase
notation: 490

C2O4= (oxalate, ethanedioate), PM10
type: Concept
description: IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, PM10
notation: 665

CCN concentration spectra
type: Concept
notation: 412

CHBrCl2 (bromodichloromethane)
type: Concept
description: IUPAC: bromo(dichloro)methane, PubChem CID: 6359, CAS Number: 75-27-4, in gas phase
notation: 12120

Ca++ (calcium), PM2.5
type: Concept
description: IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, PM2.5
notation: 633

C5H6O (3-methylfuran)
type: Concept
description: IUPAC: 3-Methylfuran, PubChem CID: 13587, CAS Number: 930-27-8, in gas phase
notation: 12096

C2Br2F4 (1,2-dibromo-1,1,2,2-tetrafluoroethane, Halon 2402)
type: Concept
description: IUPAC: 1,2-dibromo-1,1,2,2-tetrafluoroethane, PubChem CID: 31301, CAS Number: 124-73-2, in gas phase
notation: 12018

Co (cobalt)
type: Concept
description: IUPAC: cobalt, PubChem CID: 104730, CAS Number: 7440-48-4, in total deposition
notation: 601

Cloud drop effective radius
type: Concept
description: The area weighted mean radius of liquid water drops, assimilated to spheres of the same volume.
notation: 181

UV Broadband radiation
type: Concept
description: Spectrally integrated UV radiation
notation: 356

Humulus
type: Concept
description: Hop pollen
notation: 12064

Neptunium [Np-239]
type: Concept
description: IUPAC: neptunium-239, PubChem CID: 104958, CAS Number: 13968-59-7
notation: 12239

HCOO- (formate)
type: Concept
description: IUPAC: formate, PubChem CID: 283, CAS Number: 71-47-6, in total deposition
notation: 577

Particle light scattering coefficient, TSP
type: Concept
description: 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
notation: 324

Urtica
type: Concept
description: Nettle pollen
notation: 12032

Antimony [Sb-125]
type: Concept
description: IUPAC: antimony-125, PubChem CID: 6335317, CAS Number: 14234-35-6
notation: 12207

Particle number size distribution, PM10
type: Concept
description: Particle number concentration as a function of size, typically equivalent spherical radius or diameter. Size range: TSP
notation: 370

Ca++ (calcium)
type: Concept
description: IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in total deposition
notation: 545

Atmospheric pressure profile
type: Concept
description: Upper-air atmospheric pressure
notation: 12000

C2ClF5 (1-chloro-1,1,2,2,2-pentafluoroethane, CFC-115)
type: Concept
description: IUPAC: 1-chloro-1,1,2,2,2-pentafluoroethane, PubChem CID: 6430, CAS Number: 76-15-3, in gas phase
notation: 591

cerium [Ce-144]
type: Concept
description: IUPAC: cerium-144, PubChem CID: 26874, CAS Number: 14762-78-8
notation: 12221

CH2O (methanal, formaldehyde)
type: Concept
description: IUPAC: formaldehyde, PubChem CID: 712, CAS Number: 50-00-0, in gas phase
notation: 489

Molybdenum [Mo-99]
type: Concept
description: IUPAC: molybdenum-99, PubChem CID: 104976, CAS Number: 14119-15-4
notation: 12197

Mn (manganese), TSP
type: Concept
description: IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in particle phase, TSP
notation: 702

CHBr2Cl (dibromochloromethane)
type: Concept
description: IUPAC: dibromo(chloro)methane, PubChem CID: 31296, CAS Number: 124-48-1, in gas phase
notation: 12119

CHBr3 (bromoform)
type: Concept
description: IUPAC: bromoform, PubChem CID: 5558, CAS Number: 75-25-2, in gas phase
notation: 282

C5H10 (cyclopentane)
type: Concept
description: IUPAC: cyclopentane, PubChem CID: 9253, CAS Number: 287-92-3, in gas phase
notation: 457

Water vapour
type: Concept
notation: 12165

SO2F2 (sulfuryl fluoride)
type: Concept
description: IUPAC: sulfuryl difluoride, PubChem CID: 17607, CAS Number: 2699-79-8, in gas phase
notation: 204

Turbulence type (low levels and wake vortex)
type: Concept
notation: 250

As (arsenic), TSP
type: Concept
description: IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in particle phase, TSP
notation: 678

C10H16 (D-limonene)
type: Concept
description: IUPAC: (4R)-1-methyl-4-prop-1-en-2-ylcyclohexene, PubChem CID: 440917, CAS Number: 5989-27-5, in gas phase
notation: 12133

Net long-wave irradiance
type: Concept
description: 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.
notation: 12308

C6H14 (2,2-dimethylbutane)
type: Concept
notation: 471

NH4+ (ammonium), PM2.5
type: Concept
description: IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, PM2.5
notation: 646

C2H5NO3 (ethyl nitrate)
type: Concept
description: IUPAC: Ethyl nitrate, PubChem CID: 12259, CAS Number: 625-58-1, in gas phase
notation: 12101

Cu (copper), PM10
type: Concept
description: IUPAC: copper, PubChem CID: 23978, CAS Number: 7440-50-8, in particle phase, PM10
notation: 692

Cl- (chloride), PM1
type: Concept
description: IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM1
notation: 614

CO2 (carbon dioxide)
type: Concept
description: IUPAC: carbon dioxide, PubChem CID: 280, CAS Number: 124-38-9, in gas phase
notation: 194

Particle number concentration
type: Concept
description: Amount of particles per unit volume of air
notation: 369

Other chemical components, coarse
type: Concept
description: Other chemical components, coarse
notation: 660

Ostrya
type: Concept
description: Hophornbeam pollen
notation: 12077

Spectral bidirectional reflectance
type: Concept
description: 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.
notation: 12298

C14H10 (anthracene), in air and aerosol
type: Concept
description: IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in aerosol
notation: 337

Total Oleaceae
type: Concept
description: Olive family pollen
notation: 12045

C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in wet precipitation
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in wet deposition
notation: 383

C4F8 (octafluorocyclobutane, PFC-318)
type: Concept
description: IUPAC: 1,1,2,2,3,3,4,4-octafluorocyclobutane, PubChem CID: 8263, CAS Number: 115-25-3, in gas phase
notation: 12091

C3H3F5 (1,1,1,3,3-Pentafluoropropane, HFC-245fa)
type: Concept
description: IUPAC: 1,1,1,3,3-pentafluoropropane, PubChem CID: 68030, CAS Number: 460-73-1, in gas phase
notation: 558

Gust Speed
type: Concept
notation: 305

C18H12 (benz(a)anthracene), in total precipitation
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in total precipitation
notation: 351

Obscuration type
type: Concept
notation: 526

Thorium [Th-232]
type: Concept
description: IUPAC: thorium-232, PubChem CID: 11817119, CAS Number: n/a
notation: 12234

Direct downward short-wave irradiance
type: Concept
description: 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.
notation: 572

Silver [Ag-110m]
type: Concept
description: Metastable (excited) state of silver-110 isotope, IUPAC: silver-110, PubChem CID: 104828, CAS Number: 14391-76-5
notation: 12202

Turbulence
type: Concept
description: Kinetic energy density of turbulent motion of the air
notation: 249

F- (fluoride)
type: Concept
description: IUPAC: fluoride, PubChem CID: 28179, CAS Number: 16984-48-8, in total deposition
notation: 540

Th (thorium), PM2.5
type: Concept
description: IUPAC: thorium, PubChem CID: 23960, CAS Number: 7440-29-1, in particle phase, PM2.5
notation: 715

Electric conductivity
type: Concept
notation: 295

Characteristic of pressure tendency
type: Concept
description: 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.
notation: 217

Chromium [Cr-51]
type: Concept
description: IUPAC: chromium-51, PubChem CID: 104786, CAS Number: 14392-02-0
notation: 12178

Total column ozone
type: Concept
notation: 263

C2H6S (dimethylsulfide, DMS)
type: Concept
description: IUPAC: methylsulfanylmethane, PubChem CID: 1068, CAS Number: 75-18-3, in gas phase
notation: 438

Particle single scattering albedo
type: Concept
description: Ratio of particle scattering coefficient to particle extinction coefficient or sum of particle absorption and scattering coefficients.
notation: 12146

C8H10 (m-xylene)
type: Concept
description: IUPAC: 1,3-xylene, PubChem CID: 7929, CAS Number: 108-38-3, in gas phase
notation: 484

Strontium [Sr-91]
type: Concept
description: IUPAC: strontium-91, PubChem CID: 6337043, CAS Number: 14331-91-0
notation: 12192

Major inorganic components, fine
type: Concept
description: Major inorganic components, fine
notation: 659

C2H2Cl2 ((Z)-1,2-dichloroethene, cis-1,2-dichloroethene)
type: Concept
description: IUPAC: (Z)-1,2-dichloroethene, PubChem CID: 643833, CAS Number: 156-59-2, in gas phase
notation: 12114

C4H8O (butanal isomers)
type: Concept
notation: 452

Particle light hemispheric forward scattering coefficient
type: Concept
description: Incident radiative flux scattered into all forward angles, i.e. scattering_angle from zero to pi/2 radians.
notation: 12160

Al (aluminium), PM2.5
type: Concept
description: IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in particle phase, PM2.5
notation: 673

C3F8 (octafluoropropane, PFC-218)
type: Concept
description: IUPAC: 1,1,1,2,2,3,3,3-octafluoropropane, PubChem CID: 6432, CAS Number: 76-19-7, in gas phase
notation: 420

Observed variable - measurand (atmosphere)
type: Register
type: Container
type: Collection
description: Observed variable - measurand (atmosphere)
modified: 2026-06-11T15:18:55.016Z
version info: 277
member: Sb (antimony), TSP
member: U (uranium), PM2.5
member: Ca++ (calcium), TSP
member: Cd (cadmium), PM1
member: HCOO- (formate)
member: Na+ (sodium), PM10
member: Cr (chromium), TSP
member: C2ClF5 (1-chloro-1,1,2,2,2-pentafluoroethane, CFC-115)
member: SO2
member: NMHC
member: Hygroscopic growth factor, 50 μm equivalent
member: cerium [Ce-141]
member: Brightness temperature
member: Tritium [H-3]
member: C2H4O2 (methyl formate)
member: C4H8O2 (methyl propionate)
member: Ångström exponent for aerosol optical depth
member: Particle effective radius
member: C10H16 (alpha-pinene)
member: Rate of ice accretion
member: Melting layer depth in clouds
member: Krypton [Kr-85]
member: CH2Cl2 (dichloromethane)
member: COF2 (difluoromethanal, carbonyl fluoride)
member: HDO (as a chemical species)
member: Cloud amount
member: Mn (manganese), PM10
member: Major inorganic components, fine
member: C2O4= (oxalate, ethanedioate), TSP
member: t-C5H10 (trans-2-pentene)
member: C5H10 (2-methyl-2-butene)
member: C5H12 (2,2-dimethylpropane)
member: C3H2F6 (1,1,1,3,3,3-hexafluoropropane, HFC-236fa)
member: C4H6O (but-3-en-2-one, methylvinylketone)
member: Zirconium [Zr-95]
member: Plutonium [Pu-238]
member: Particle light scattering coefficient, PM10
member: Height of the top of the PBL
member: Selenium [Se-75]
member: Freezing level height in clouds
member: Wind (surface wind direction and speed, horizontal) - deprecated
member: HNO3 (nitric acid)
member: Particle light absorption coefficient, PM1
member: Total Cyperaceae
member: Total Arecaceae
member: Ambrosia
member: Total Betulaceae
member: Ulmus
member: Tilia
member: Ni (nickel)
member: U (uranium), TSP
member: Cl- (chloride), PM1
member: SO4= (sulfate), PM10
member: Carbonaceous-organic material, PM10
member: Diffuse downward short-wave irradiance
member: CHClF2 (chlorodifluoromethane, HCFC-22)
member: C3H2F6 (1,1,1,2,3,3-hexafluoropropane, HFC-236ea)
member: C9H12 (1,2,4-trimethylbenzene)
member: Xenon [Xe-133]
member: Impact parameter
member: Solar total irradiance
member: Antimony [Sb-124]
member: C2H2Cl2 (1,2-dichloroethene)
member: C18H12 (benz(a)anthracene), in air
member: C5H4O2 (furfural)
member: C10H16 (beta-pinene)
member: C8H18 (2,2,4-trimethylpentane)
member: N2O (nitrous oxide)
member: Lightning discharge polarity
member: C5H6O (2-methylfuran)
member: CH4 (methane, C-13)
member: Past weather
member: Cloud cover

Zenith total delay (ZTD)
type: Concept
description: 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.
notation: 12303

Na+ (sodium), PM10
type: Concept
description: IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, PM10
notation: 641

Aesculus
type: Concept
description: Aesculus pollen
notation: 12058

NO2 (nitrogen dioxide)
type: Concept
description: IUPAC: n/a, PubChem CID: 3032552, CAS Number: 10102-44-0, in gas phase
notation: 396

Particle light absorption coefficient, TSP
type: Concept
description: 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
notation: 318

Larix
type: Concept
description: Larch pollen
notation: 12026

Particle mass concentration, PM10
type: Concept
description: Mass of particles per unit volume of air, size range: PM10
notation: 364

Total Rosaceae
type: Concept
description: Rose family pollen
notation: 12072

Cl- (chloride)
type: Concept
description: IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in total deposition
notation: 539

Neodymium [Nd-137]
type: Concept
description: IUPAC: neodymium-137
notation: 12247

CBrClF2 (Halon 1211)
type: Concept
description: IUPAC: bromo-chloro-difluoromethane, PubChem CID: 9625, CAS Number: 353-59-3, in gas phase
notation: 332

Corylus
type: Concept
description: Hazel pollen
notation: 12040

Optical depth of fog
type: Concept
description: 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].
notation: 507

Caesium [Cs-136]
type: Concept
description: IUPAC: cesium-136, PubChem CID: 6335316, CAS Number: 14234-29-8
notation: 12215

Type of middle clouds
type: Concept
description: 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.]
notation: 553

Volcanic ash particle mass concentration
type: Concept
description: 3D field of mass mixing ratio of volcanic ash
notation: 728

Extinction coefficient
type: Concept
notation: 521

C2HCl3 (trichloroethene)
type: Concept
description: IUPAC: 1,1,2-trichloroethene, PubChem CID: 6575, CAS Number: 79-01-6, in gas phase
notation: 276

Particle light backscatter coefficient
type: Concept
description: The fraction of incident radiative flux scattered backward at 180 degrees.
notation: 12159

i-C4H10 (2-methylpropane, iso-butane)
type: Concept
description: IUPAC: 2-methylpropane, PubChem CID: 6360, CAS Number: 75-28-5, in gas phase
notation: 497

C2F6 (hexafluoroethane, PFC-116)
type: Concept
description: IUPAC: 1,1,1,2,2,2-hexafluoroethane, PubChem CID: 6431, CAS Number: 76-16-4, in gas phase
notation: 419

C6H5Cl (chlorobenzene)
type: Concept
description: IUPAC: chlorobenzene, PubChem CID: 7964, CAS Number: 108-90-7, in gas phase
notation: 12127

Se (selenium), TSP
type: Concept
description: IUPAC: selenium, PubChem CID: 6326970, CAS Number: 7782-49-2, in particle phase, TSP
notation: 710

C5H8 (cyclopentene)
type: Concept
description: IUPAC: cyclopentene, PubChem CID: 8882, CAS Number: 142-29-0, in gas phase
notation: 465

Intensity of precipitation
type: Concept
notation: 212

Sodium [Na-24]
type: Concept
description: IUPAC: sodium-24, PubChem CID: 6335498, CAS Number: 13982-04-2
notation: 12173

Cd (cadmium), PM2.5 - PM10
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM2.5 - PM10
notation: 686

Lightning discharge distance from station
type: Concept
description: Distance of the lightning event from the corresponding station.
notation: 433

C3H6O2 (1,3-dioxolane)
type: Concept
description: IUPAC: 1,3-dioxolane, PubChem CID: 12586, CAS Number: 646-06-0, in gas phase
notation: 12141

V (vanadium)
type: Concept
description: IUPAC: vanadium, PubChem CID: 23990, CAS Number: 7440-62-2, in total deposition
notation: 608

Long-wave earth surface emissivity
type: Concept
description: Emissivity of the earth surface integrated over the thermal IR wavelength range and integrated hemispherically.
notation: 12316

PSC occurrence
type: Concept
description: Polar Stratospheric Clouds occurrence. - Accuracy expressed as Hit Rate [HR] and False Alarm Rate [FAR]. Simplified: [FAR/HR]
notation: 188

Sum of NH3 (ammonia) and NH4+ (ammonium)
type: Concept
description: Sum of NH3 (ammonia) and NH4+ (ammonium)
notation: 654

Carpinus
type: Concept
description: Hornbeam pollen
notation: 12039

SO4= (sulfate), PM2.5
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, PM2.5
notation: 622

Water vapour amount fraction
type: Concept
description: 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'.
notation: 12330

C12H8Cl6 (aldrin), in air and aerosol
type: Concept
description: 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
notation: 377

Cladosporium
type: Concept
description: Cladosporium spores
notation: 12085

As (arsenic)
type: Concept
description: IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in total deposition
notation: 598

C16H10 (pyrene), in air and aerosol
type: Concept
description: IUPAC: pyrene, PubChem CID: 31423, CAS Number: 129-00-0, in aerosol
notation: 345

Secale
type: Concept
description: Secale pollen
notation: 12053

bismuth [Bi-212]
type: Concept
description: IUPAC: bismuth-212, PubChem CID: 6335500, CAS Number: 14913-49-6
notation: 12228

C2H3O5N (peroxyacetylnitrate, PAN)
type: Concept
description: IUPAC: nitro ethaneperoxoate, PubChem CID: 16782, CAS Number: 2278-22-0, in gas phase
notation: 391

Downward long-wave irradiance
type: Concept
description: Flux density of downwelling long-wave radiation, at a specified level within the atmosphere, including the Earth surface.
notation: 566

O2/N2 ratio
type: Concept
description: Atmospheric O2/N2 ratio
notation: 12021

C2H3Cl2F (1,1-dichloro-1-fluoroethane, HCFC-141b)
type: Concept
description: IUPAC: 1,1-dichloro-1-fluoroethane, PubChem CID: 15586, CAS Number: 1717-00-6, in gas phase
notation: 534

Gold [Au-198]
type: Concept
description: IUPAC: gold-198, PubChem CID: 66274, CAS Number: 10043-49-9
notation: 12242

Rb (rubidium), TSP
type: Concept
description: IUPAC: rubidium, PubChem CID: 5357696, CAS Number: 7440-17-7, in particle phase, TSP
notation: 709

HF (hydrofluoric acid)
type: Concept
description: IUPAC: fluorane, PubChem CID: 14917, CAS Number: 7664-39-3, in gas phase
notation: 289

n-C5H12 (n-pentane)
type: Concept
description: IUPAC: pentane, PubChem CID: 8003, CAS Number: 109-66-0, in gas phase
notation: 502

Iodine [I-131], elementary
type: Concept
description: IUPAC: n/a, PubChem CID: 24855, CAS Number: 10043-66-0
notation: 12210

Lightning discharge current
type: Concept
description: Current incurred by the lightning discharge.
notation: 257

Zn (zinc), PM2.5
type: Concept
description: IUPAC: zinc, PubChem CID: 23994, CAS Number: 7440-66-6, in particle phase, PM2.5
notation: 723

C6Hn, n={14, 12} (sum of 2,2-dimethylbutane and methylcyclopentane)
type: Concept
description: sum of 2,2-dimethylbutane and methylcyclopentane, in gas phase
notation: 478

Dew-point temperature (at specified distance from reference surface)
type: Concept
notation: 225

Zinc [Zn-65]
type: Concept
description: IUPAC: zinc-65, PubChem CID: 91574, CAS Number: 13982-39-3
notation: 12186

C8H18 (n-octane)
type: Concept
description: IUPAC: Octane, PubChem CID: 356, CAS Number: 111-65-9, in gas phase
notation: 12108

Surface albedo
type: Concept
description: Hemispherically integrated reflectance of the Earth surface in the range 0.4-0.7 µm.
notation: 271

Li (lithium), PM2.5
type: Concept
description: IUPAC: lithium, PubChem CID: 3028194, CAS Number: 7439-93-2, in particle phase, PM2.5
notation: 699

C4H6 (1,3-butadiene, butadiene)
type: Concept
description: IUPAC: buta-1,3-diene, PubChem CID: 7845, CAS Number: 106-99-0, in gas phase
notation: 446

Particle mass size distribution
type: Concept
description: Particle mass concentration as a function of size, typically equivalent spherical radius or diameter.
notation: 12154

Lightning flash density cloud-to-ground
type: Concept
description: Number of detected cloud-to-ground flashes in the corresponding time interval and space unit.
notation: 12329

CH3CN (acetonitrile)
type: Concept
description: IUPAC: acetonitrile, PubChem CID: 6342, CAS Number: 75-05-8, in gas phase
notation: 492

CH3O3S- (methanesulfonate), PM1
type: Concept
description: IUPAC: methanesulfonate, PubChem CID: 85257, CAS Number: 16053-58-0, in particle phase, PM1
notation: 667

Hygroscopic growth factor, 165 μm equivalent
type: Concept
notation: 414

CH2I2 (diiodomethane)
type: Concept
description: IUPAC: diiodomethane, PubChem CID: 6346, CAS Number: 75-11-6, in gas phase
notation: 12122

C5H10O (pentanal, valeraldehyde)
type: Concept
description: IUPAC: pentanal, PubChem CID: 8063, CAS Number: 110-62-3, in gas phase
notation: 460

Mg++ (magnesium), PM10
type: Concept
description: IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, PM10
notation: 635

C3H5N (propanenitrile)
type: Concept
description: IUPAC: Propanenitrile, PubChem CID: 7854, CAS Number: 107-12-0, in gas phase
notation: 12098

Bi (bismuth), PM2.5
type: Concept
description: IUPAC: bismuth, PubChem CID: 5359367, CAS Number: 7440-69-9, in particle phase, PM2.5
notation: 681

Fe (iron)
type: Concept
description: IUPAC: iron, PubChem CID: 23925, CAS Number: 7439-89-6, in total deposition
notation: 603

Solar spectral irradiance
type: Concept
description: Spectrally resolved flux density of radiation received from the sun at the top of the atmosphere.
notation: 12311

Effective radius of cloud hydrometeors
type: Concept
description: 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.
notation: 183

UV Multiband radiation
type: Concept
description: UV radiation measured across several discrete, narrow wavebands (e.g. 10 nm) within the UV range, providing coarse spectral information
notation: 358

Hippophae
type: Concept
description: Sea-buckthorn pollen
notation: 12066

Acidity-Alkalinity, TSP
type: Concept
notation: 579

Vertical distribution of properties
type: Concept
notation: 326

Fagus
type: Concept
description: Beech pollen
notation: 12034

Iodine [I-126], elementary
type: Concept
description: IUPAC: n/a, PubChem CID: 161029, CAS Number: 14158-32-8
notation: 12209

Ginkgo
type: Concept
description: Ginkgo pollen
notation: 12080

K+ (potassium)
type: Concept
description: IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in total deposition
notation: 547

Lightning density cloud-to-ground
type: Concept
notation: 12002

CCl3F (trichlorofluoromethane, CFC-11)
type: Concept
description: IUPAC: trichloro(fluoro)methane, PubChem CID: 6389, CAS Number: 75-69-4, in gas phase
notation: 593

C14H10 (phenanthrene), in aerosol
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in particle phase
notation: 340

Neodymium [Nd-147]
type: Concept
description: IUPAC: neodymium-147, PubChem CID: 114848, CAS Number: 14269-74-0
notation: 12223

CH2F2 (difluoromethane, HFC-32)
type: Concept
description: IUPAC: difluoromethane, PubChem CID: 6345, CAS Number: 75-10-5, in gas phase
notation: 561

Special phenomena
type: Concept
notation: 56

Ruthenium [Ru-103]
type: Concept
description: IUPAC: ruthenium-103, PubChem CID: 104749, CAS Number: 13968-53-1
notation: 12199

Ni (nickel), PM10
type: Concept
description: IUPAC: nickel, PubChem CID: 935, CAS Number: 7440-02-0, in particle phase, PM10
notation: 704

CO
type: Concept
description: IUPAC: carbon monoxide, PubChem CID: 281, CAS Number: 630-08-0, in gas phase
notation: 284

C5H10 (sum of pentenes)
type: Concept
notation: 459

H2O (as a chemical species)
type: Concept
description: IUPAC: oxidane, PubChem CID: 962, CAS Number: 7732-18-5, in gas phase
notation: 206

Cloud phase
type: Concept
description: Aggregate state of cloud particles, either water droplets/drops, snowflakes, ice/snow crystals, or mixed.
notation: 12167

Integrated water vapour
type: Concept
description: 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).
notation: 252

C2H2O2 (glyoxal)
type: Concept
description: IUPAC: oxaldehyde, PubChem CID: 7860, CAS Number: 107-22-2, in gas phase
notation: 12135

C6H14 (3-methylpentane)
type: Concept
description: IUPAC: 3-methylpentane, PubChem CID: 7282, CAS Number: 96-14-0, in gas phase
notation: 473

Iron [Fe-59]
type: Concept
description: IUPAC: iron-59, PubChem CID: 104784, CAS Number: 14596-12-4
notation: 12181

CO2 [C-14]
type: Concept
description: CO2 with C-14 isotope
notation: 220

NH4NO4 (ammonium nitrate), TSP
type: Concept
description: IUPAC: ammonium nitrate, PubChem CID: 22985, CAS Number: 6484-52-2, in particle phase, TSP
notation: 648

C4H9NO3 (n-butyl nitrate)
type: Concept
description: IUPAC: Butyl nitrate, PubChem CID: 13567, CAS Number: 928-45-0, in gas phase
notation: 12103

Fe (iron), TSP
type: Concept
description: IUPAC: iron, PubChem CID: 23925, CAS Number: 7439-89-6, in particle phase, TSP
notation: 694

C3H4O2 (2-oxopropanal, methylglyoxal)
type: Concept
description: IUPAC: 2-oxopropanal, PubChem CID: 880, CAS Number: 78-98-8, in gas phase
notation: 441

Cl- (chloride), PM2.5
type: Concept
description: IUPAC: chloride, PubChem CID: 312, CAS Number: 16887-00-6, in particle phase, PM2.5
notation: 616

CO2 [O-18]
type: Concept
description: CO2 with O-18 isotope
notation: 196

Buxus
type: Concept
description: Box pollen
notation: 12079

C2H3O2- (CH3COO-, acetate), PM1
type: Concept
description: IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-0, in particle phase, PM1
notation: 662

C14H10 (phenanthrene), PM10
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in particle phase, PM10
notation: 339

Fraxinus
type: Concept
description: Ash pollen
notation: 12047

C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, gamma-lindane, gamma-HCH), in wet precipitation
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in wet deposition
notation: 385

C3H8O (2-propanol)
type: Concept
description: IUPAC: Propan-2-ol, PubChem CID: 3776, CAS Number: 67-63-0, in gas phase
notation: 12093

w (vertical component of wind vector)
type: Concept
description: 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.
notation: 307

Sambucus
type: Concept
description: Sambucus (elder) pollen
notation: 12061

Uranium [U-235]
type: Concept
description: IUPAC: uranium-235, PubChem CID: 61784, CAS Number: 15117-96-1
notation: 12236

Upward short-wave irradiance
type: Concept
description: Flux density of upwelling short-wave radiation, at the top of the atmosphere or a specified level within the atmosphere, including the Earth surface.
notation: 574

Light backscattering coefficient, total aerosol
type: Concept
notation: 321

Tin [Sn-113]
type: Concept
description: IUPAC: tin-113, PubChem CID: 6335514, CAS Number: 13966-06-8
notation: 12204

PO4--- (phosphate)
type: Concept
description: IUPAC: phosphate, PubChem CID: 1061, CAS Number: 14265-44-2, in total deposition
notation: 542

Specific humidity
type: Concept
description: 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.]
notation: 12250

Sn (tin), PM2.5
type: Concept
description: IUPAC: tin, PubChem CID: 5352426, CAS Number: 7440-31-5, in particle phase, PM2.5
notation: 717

Aerological soundings
type: Concept
notation: 37

Beryllium [Be-7]
type: Concept
description: IUPAC: beryllium-7, PubChem CID: 6335489, CAS Number: 13966-02-4
notation: 219

Past weather
type: Concept
description: 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.]
notation: 265

Ångström exponent for particle light scattering
type: Concept
description: A measure of dependence of the particle light scattering coefficient on wavelength expressed in power law relationship.
notation: 12148

C8H10 (Sum of p-xylene and m-xylene, 1,3- and 1,4-dimethylbenzene)
type: Concept
notation: 486

Yttrium [Y-90m]
type: Concept
description: Metastable (excited) state of yttrium-90 isotope, IUPAC: yttrium-90, PubChem CID: 104760, CAS Number: 10098-91-6
notation: 12194

C2H2Cl2 (1,2-dichloroethene)
type: Concept
description: IUPAC: 1,2-dichloroethene, PubChem CID: 10900, CAS Number: 540-9-0, in gas phase
notation: 12116

C5H10 (2-methyl-1-butene)
type: Concept
description: IUPAC: 2-methylbut-1-ene, PubChem CID: 11240, CAS Number: 563-46-2, in gas phase
notation: 454

N2O (nitrous oxide)
type: Concept
description: IUPAC: nitrous oxide, PubChem CID: 948, CAS Number: 10024-97-2, in gas phase
notation: 201

Aerosol layer height
type: Concept
description: Height of vertically localized aerosol layer above sea level
notation: 12162

Sb (antimony), PM2.5
type: Concept
description: IUPAC: antimony, PubChem CID: 5354495, CAS Number: 7440-36-0, in particle phase, PM2.5
notation: 675

C10H16 (beta-pinene)
type: Concept
description: IUPAC: 6,6-dimethyl-2-methylidenebicyclo[3.1.1]heptane, PubChem CID: 14896, CAS Number: 127-91-3, in gas phase
notation: 12130

Impact parameter
type: Concept
description: 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.
notation: 12305

Na+ (sodium), TSP
type: Concept
description: IUPAC: sodium(1+), PubChem CID: 923, CAS Number: 17341-25-2, in particle phase, TSP
notation: 643

NOy
type: Concept
notation: 398

Total Cupressaceae
type: Concept
description: Cypress family pollen
notation: 12028

Particle mass concentration, PM2.5
type: Concept
description: Mass of particles per unit volume of air, size range: PM2.5
notation: 366

Total Ranunculaceae
type: Concept
description: Buttercup family pollen
notation: 12074

Relative humidity (with respect to water)
type: Concept
description: 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.]
notation: 12249

Radiance
type: Concept
description: 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'.
notation: 12295

C13H10 (9H-fluorene, fluorene), in air
type: Concept
description: IUPAC: 9H-fluorene, PubChem CID: 6853, CAS Number: 86-73-7, in gas phase
notation: 334

Chenopodium
type: Concept
description: Chenopodium (goosefoot) pollen
notation: 12042

Short-wave cloud reflectance
type: Concept
description: Reflectance of the solar radiation from clouds
notation: 509

barium [Ba-133]
type: Concept
description: IUPAC: barium-133, PubChem CID: 5491664, CAS Number: 13981-41-4
notation: 12217

C6Cl6 (hexachlorobenzene, HCB), in air
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorobenzene, PubChem CID: 8370, CAS Number: 118-74-1, in gas phase
notation: 380

C2H4F2 (1,1-difluoroethane, HFC-152a)
type: Concept
description: IUPAC: 1,1-difluoroethane, PubChem CID: 6368, CAS Number: 75-37-6, in gas phase
notation: 555

S (sulfur)
type: Concept
description: IUPAC: sulfur, PubChem CID: n/a, CAS Number: 7704-34-9, in total deposition
notation: 302

Hydrometeor type
type: Concept
notation: 523

Lead [Pb-214]
type: Concept
description: IUPAC: lead-214, PubChem CID: 6328551, CAS Number: 15067-28-4
notation: 12231

CH2Cl2 (dichloromethane)
type: Concept
description: IUPAC: dichloromethane, PubChem CID: 6344, CAS Number: 75-09-2, in gas phase
notation: 278

i-C5H12 (2-methylbutane, iso-pentane)
type: Concept
description: IUPAC: 2-methylbutane, PubChem CID: 6556, CAS Number: 78-78-4, in gas phase
notation: 499

C10H16 (alpha-pinene)
type: Concept
description: IUPAC: 2,6,6-trimethylbicyclo[3.1.1]hept-2-ene, PubChem CID: 6654, CAS Number: 80-56-8, in gas phase
notation: 12129

Sr (strontium), TSP
type: Concept
description: IUPAC: strontium, PubChem CID: 5359327, CAS Number: 7440-24-6, in particle phase, TSP
notation: 712

C5Hn, n={12, 10} (sum of n-pentane and cyclopentane)
type: Concept
description: Sum of n-pentane and cyclopentane, in gas phase
notation: 467

Potassium [K-40]
type: Concept
description: IUPAC: potassium-40, PubChem CID: 6328542, CAS Number: 13966-00-2
notation: 12175

Rate of ice accretion
type: Concept
notation: 214

Lightning discharge type (cloud to cloud, cloud to surface)
type: Concept
description: 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).
notation: 260

Ce (cerium), PM2.5
type: Concept
description: IUPAC: cerium, PubChem CID: 23974, CAS Number: 7440-45-1, in particle phase, PM2.5
notation: 688

C2H2O2 (oxaldehyde, ethanedial)
type: Concept
description: IUPAC: oxaldehyde, PubChem CID: 7860, CAS Number: 107-22-2, in gas phase
notation: 435

C4H8O2 (methyl propionate)
type: Concept
description: IUPAC: methyl propanoate, PubChem CID: 11124, CAS Number: 554-12-1, in gas phase
notation: 12143

C7H6O (benzene carbaldehyde)
type: Concept
notation: 481

Major chemical components
type: Concept
description: Major chemical components
notation: 656

C4H6O ((Z)-crotonaldehyde, cis-2-butenal)
type: Concept
description: IUPAC: (Z)-but-2-enal, PubChem CID: 673950, CAS Number: 15798-64-8, in gas phase
notation: 12111

Elemental carbon, PM1
type: Concept
description: 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
notation: 624

C12H8Cl6 (aldrin), in wet precipitation
type: Concept
description: 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
notation: 379

CH3D (monodeuterated methane, methane-d1)
type: Concept
description: IUPAC: deuteriomethane, PubChem CID: 12669, CAS Number: 676-49-3, in gas phase
notation: 12087

Carbonaceous-organic material, PM10
type: Concept
notation: 670

Bending angle
type: Concept
description: The angle through which an electromagnetic wave is refracted when passing along an atmospheric path, used particularly for GNSS radio occultation observations.
notation: 12300

C18H12 (benz(a)anthracene), in aerosol
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in particle phase
notation: 347

Juglans
type: Concept
description: Walnut tree pollen
notation: 12055

HCN (formonitrile, hydrogen cyanide)
type: Concept
description: IUPAC: formonitrile, PubChem CID: 768, CAS Number: 74-90-8, in gas phase
notation: 393

NH4+ (ammonium)
type: Concept
description: IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in total deposition
notation: 568

Aerosol Extinction Coefficient
type: Concept
description: Spectral volumetric extinction cross-section of aerosol particles.
notation: 315

Total Pinaceae
type: Concept
description: Pine family pollen
notation: 12023

Aerosol column burden (mass density)
type: Concept
description: 2D field of the column burden of condensed particles in the atmosphere
notation: 361

C2H3F3 (1,1,1-trifluoroethane, HFC-143a)
type: Concept
description: IUPAC: 1,1,1-trifluoroethane, PubChem CID: 9868, CAS Number: 420-46-2, in gas phase
notation: 536

C2H2ClF3 (2-chloro-1,1,1-trifluoroethane, HCFC-133a)
type: Concept
description: IUPAC: 2-chloro-1,1,1-trifluoroethane, PubChem CID: 6408, CAS Number: 75-88-7, in gas phase
notation: 12244

t-C4H8 (trans-2-butene)
type: Concept
description: IUPAC: (E)-but-2-ene, PubChem CID: 62695, CAS Number: 107-01-7, in gas phase
notation: 504

Iodine [I-133], elementary
type: Concept
description: IUPAC: n/a, PubChem CID: 167176, CAS Number: 14834-67-4
notation: 12212

Lightning discharge rate
type: Concept
description: 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).
notation: 259

Type of cloud
type: Concept
description: Result of cloud type classification - Accuracy expressed as inverse of number of classes, so that smaller figures correspond to better performance.
notation: 550

Selenium [Se-75]
type: Concept
description: IUPAC: selenium-75, PubChem CID: 6328176, CAS Number: 14265-71-5
notation: 12188

Temperature profile
type: Concept
notation: 227

UV-B radiation
type: Concept
description: Ultraviolet radiation covering the range 280-315 nm.
notation: 273

C4H6O (but-3-en-2-one, methylvinylketone)
type: Concept
description: IUPAC: but-3-en-2-one, PubChem CID: 6570, CAS Number: 78-94-4, in gas phase
notation: 448

Hygroscopic particle light scattering growth factor
type: Concept
description: A scaling factor describing the particle scattering coefficient change as a function of relative humidity due to absorbing or evaporating water.
notation: 12156

NMHC
type: Concept
notation: 494

CHO2- (HCOO-, formate)
type: Concept
description: IUPAC: formate, PubChem CID: 283, CAS Number: 71-47-6, in particle phase
notation: 669

Hygroscopic growth factor, 50 μm equivalent
type: Concept
notation: 416

C5H4O2 (3-furaldehyde)
type: Concept
description: IUPAC: furan-3-carbaldehyde, PubChem CID: 10351, CAS Number: 498-60-2, in gas phase
notation: 12124

C5H12 (2,2-dimethylpropane)
type: Concept
description: IUPAC: 2,2-dimethylpropane, PubChem CID: 10041, CAS Number: 463-82-1, in gas phase
notation: 462

Tritium [H-3]
type: Concept
description: IUPAC: n/a, PubChem CID: 24824, CAS Number: 10028-17-8
notation: 12170

Mg++ (magnesium), TSP
type: Concept
description: IUPAC: magnesium(2+), PubChem CID: 888, CAS Number: 22537-22-0, in particle phase, TSP
notation: 637

Cd (cadmium), PM1
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM1
notation: 683

SO2
type: Concept
description: IUPAC: sulfur dioxide, PubChem CID: 1119, CAS Number: 7446 09-5, in gas phase
notation: 430

Mn (manganese)
type: Concept
description: IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in total deposition
notation: 605

Earth surface short-wave bidirectional reflectance
type: Concept
description: 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.
notation: 12313

Ligustrum
type: Concept
description: Privet pollen
notation: 12068

NO3- (nitrate), PM2.5
type: Concept
description: IUPAC: nitrate, PubChem CID: 943, CAS Number: 14797-55-8, in particle phase, PM2.5
notation: 651

Cloud ice (total column)
type: Concept
description: Field of atmospheric water in the solid phase (precipitating or not) as total column.
notation: 328

Total Betulaceae
type: Concept
description: Birch family pollen
notation: 12036

Cloud liquid water (CLW, total column)
type: Concept
description: Field of atmospheric water in the liquid phase (precipitating or not).
notation: 374

Mercurialis
type: Concept
description: Mercuries pollen
notation: 12082

CH3CCl3 (1,1,1-trichloroethane, methyl chloroform)
type: Concept
description: IUPAC: 1,1,1-trichloroethane, PubChem CID: 6278, CAS Number: 71-55-6, in gas phase
notation: 595

C14H10 (phenanthrene), in air and aerosol
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in aerosol
notation: 342

Artemisia
type: Concept
description: Mugwort pollen
notation: 12050

Tantalum [Ta-182]
type: Concept
description: IUPAC: tantalum-182, PubChem CID: 161013, CAS Number: 13982-00-8
notation: 12225

Upper wind (X, Y components, horizontal)
type: Concept
description: Horizontal component of wind as a vector in an orthogonal coordinate system.
notation: 310

Cloud base height
type: Concept
description: For surface observations, height of the cloud base above ground level; for aircraft observations, altitude of the cloud base above mean sea level.
notation: 531

P (phosphorous), PM2.5
type: Concept
description: IUPAC: phosphorus, PubChem CID: 5462309, CAS Number: 7723-14-0, in particle phase, PM2.5
notation: 706

ClO (chlorine monoxide)
type: Concept
description: IUPAC: n/a, PubChem CID: 166686, CAS Number: 14989-30-1, in gas phase
notation: 286

Aerosol type
type: Concept
description: 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.
notation: 12169

Object wetness duration
type: Concept
notation: 254

CS2 (carbon disulfide)
type: Concept
description: IUPAC: methanedithione, PubChem CID: 6348, CAS Number: 75-15-0, in gas phase
notation: 429

U (uranium), TSP
type: Concept
description: IUPAC: uranium, PubChem CID: 23989, CAS Number: 7440-61-1, in particle phase, TSP
notation: 720

C2H4O2 (glycolaldehyde)
type: Concept
description: IUPAC: 2-hydroxyacetaldehyde, PubChem CID: 756, CAS Number: 141-46-8, in gas phase
notation: 12137

C6H14 (sum of methylpentanes)
type: Concept
notation: 475

Cobalt [Co-57]
type: Concept
description: IUPAC: cobalt-57, PubChem CID: 104851, CAS Number: 13981-50-5
notation: 12183

Lead [Pb-210]
type: Concept
description: IUPAC: lead-210, PubChem CID: 6328175, CAS Number: 14255-04-0
notation: 222

C4H9NO3 (t-butyl nitrate)
type: Concept
description: IUPAC: tert-Butyl nitrite, PubChem CID: 10906, CAS Number: 540-80-7, in gas phase
notation: 12105

La (lanthanum), TSP
type: Concept
description: IUPAC: lanthanum, PubChem CID: 23926, CAS Number: 7439-91-0, in particle phase, TSP
notation: 696

C3H6O (acetone, propanone)
type: Concept
description: IUPAC: propan-2-one, PubChem CID: 180, CAS Number: 67-64-1, in gas phase
notation: 443

Ångström exponent for aerosol absorption optical depth
type: Concept
description: A measure of dependence of the aerosol absorption optical depth on wavelength expressed in power law relationship.
notation: 12151

F- (fluoride), TSP
type: Concept
description: IUPAC: fluoride, PubChem CID: 28179, CAS Number: 16984-48-8, in particle phase, TSP
notation: 618

u (u component of horizontal wind vector)
type: Concept
description: 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.
notation: 12326

C2O4= (oxalate, ethanedioate), PM1
type: Concept
description: IUPAC: oxalate, PubChem CID: 71081, CAS Number: 338-70-5, in particle phase, PM1
notation: 664

CCN concentration at single supersaturation
type: Concept
notation: 411

Ambrosia
type: Concept
description: Ragweed pollen
notation: 12049

Ca++ (calcium), PM10
type: Concept
description: IUPAC: calcium(2+), PubChem CID: 271, CAS Number: 14127-61-8, in particle phase, PM10
notation: 632

C5H6O (2-methylfuran)
type: Concept
description: IUPAC: 2-Methylfuran, PubChem CID: 10797, CAS Number: 534-22-5, in gas phase
notation: 12095

Wind (surface wind direction and speed, horizontal) - deprecated
type: Concept
description: Horizontal component of wind as speed and direction.
notation: 309

Cr (chromium)
type: Concept
description: IUPAC: chromium, PubChem CID: 23976, CAS Number: 7440-47-3, in total deposition
notation: 600

CBr2F2 (dibromodifluoromethane, Halon 1202)
type: Concept
description: IUPAC: dibromo(difluoro)methane, PubChem CID: 6382, CAS Number: 75-61-6, in gas phase
notation: 12017

Cloud cover
type: Concept
description: 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.
notation: 180

Tilia
type: Concept
description: Linden pollen
notation: 12063

Plutonium [Pu-238]
type: Concept
description: IUPAC: plutonium-238, PubChem CID: 61709, CAS Number: 13981-16-3
notation: 12238

CH3COO- (acetate)
type: Concept
description: IUPAC: acetate, PubChem CID: 175, CAS Number: 71-50-1, in total deposition
notation: 576

Particle light scattering coefficient, PM10
type: Concept
description: 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
notation: 323

Parietaria
type: Concept
description: Pellitory pollen
notation: 12031

Antimony [Sb-124]
type: Concept
description: IUPAC: antimony-124, PubChem CID: 6335510, CAS Number: 14683-10-4
notation: 12206

SO4= (sulfate)
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in total deposition
notation: 544

U (uranium), PM2.5
type: Concept
description: IUPAC: uranium, PubChem CID: 23989, CAS Number: 7440-61-1, in particle phase, PM2.5
notation: 719

Atmospheric density
type: Concept
description: Density of the atmosphere.
notation: 39

C2Cl3F3 (1,1,2-trichloro-1,2,2-trifluoroethane, CFC-113)
type: Concept
description: IUPAC: 1,1,2-trichloro-1,2,2-trifluoroethane, PubChem CID: 6428, CAS Number: 76-13-1, in gas phase
notation: 590

cerium [Ce-141]
type: Concept
description: IUPAC: cerium-141, PubChem CID: 104814, CAS Number: 13967-74-3
notation: 12220

Background luminance
type: Concept
description: 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.
notation: 267

C9H12 (1,3,5-trimethylbenzene)
type: Concept
description: IUPAC: 1,3,5-trimethylbenzene, PubChem CID: 7947, CAS Number: 108-67-8, in gas phase
notation: 488

Niobium [Nb-95]
type: Concept
description: IUPAC: niobium-95, PubChem CID: 104776, CAS Number: 13967-76-5
notation: 12196

Mn (manganese), PM10
type: Concept
description: IUPAC: manganese, PubChem CID: 23930, CAS Number: 7439-96-5, in particle phase, PM10
notation: 701

C2H4Cl2 (1,2-dichloroethane)
type: Concept
description: IUPAC: 1,2-Dichloroethane, PubChem CID: 11, CAS Number: 107-06-2, in gas phase
notation: 12118

CH3I (iodomethane)
type: Concept
description: IUPAC: iodomethane, PubChem CID: 6328, CAS Number: 74-88-4, in gas phase
notation: 281

C5H10 (3-methyl-1-butene)
type: Concept
description: IUPAC: 3-methylbut-1-ene, PubChem CID: 11239, CAS Number: 563-45-1, in gas phase
notation: 456

O3 (ozone)
type: Concept
description: IUPAC: ozone, PubChem CID: 24823, CAS Number: 10028-15-6, in gas phase
notation: 12164

SF6 (sulfur hexafluoride)
type: Concept
description: IUPAC: hexafluoro-λ6-sulfane, PubChem CID: 17358, CAS Number: 2551-62-4, in gas phase
notation: 203

As (arsenic), PM10
type: Concept
description: IUPAC: arsenic, PubChem CID: 5359596, CAS Number: 7440-38-2, in particle phase, PM10
notation: 677

C10H16 (camphene)
type: Concept
description: IUPAC: 2,2-dimethyl-3-methylidenebicyclo[2.2.1]heptane, PubChem CID: 6616, CAS Number: 79-92-5, in gas phase
notation: 12132

Short-wave irradiance (direction unspecified)
type: Concept
description: 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).
notation: 12307

Cloud amount
type: Concept
description: 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'.
notation: 179

C6H12O (hexanal isomers)
type: Concept
notation: 470

NH4+ (ammonium), PM10
type: Concept
description: IUPAC: azanium, PubChem CID: 223, CAS Number: 14798-03-9, in particle phase, PM10
notation: 645

CH3NO3 (methyl nitrate)
type: Concept
description: IUPAC: Methyl nitrate, PubChem CID: 11724, CAS Number: 598-58-3, in gas phase
notation: 12100

Co (cobalt), TSP
type: Concept
description: IUPAC: cobalt, PubChem CID: 104730, CAS Number: 7440-48-4, in particle phase, TSP
notation: 691

Tellurium [Te-131]
type: Concept
description: IUPAC: tellurium-131, PubChem CID: 6337051, CAS Number: 14683-12-6
notation: 12321

CH4 (methane, C-13)
type: Concept
description: IUPAC: methane C-13, PubChem CID: 105026, CAS Number: 14762-74-4, in gas phase
notation: 193

Particle mass concentration, TSP
type: Concept
description: Mass of particles per unit volume of air, size range: TSP
notation: 368

Total Brassicaceae
type: Concept
description: Cabbage family (mustards, crucifers) pollen
notation: 12076

C2Cl2F4 (1,2-dichlorotetrafluoroethane, CFC-114)
type: Concept
description: IUPAC: 1,2-dichloro-1,1,2,2-tetrafluoroethane, PubChem CID: 6429, CAS Number: 76-14-2
notation: 589

Brightness temperature
type: Concept
description: 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.
notation: 12297

C14H10 (anthracene), in aerosol
type: Concept
description: IUPAC: anthracene, PubChem CID: 8418, CAS Number: 120-12-7, in particle phase
notation: 336

Salix
type: Concept
description: Willow pollen
notation: 12044

cerium [Ce-139]
type: Concept
description: IUPAC: cerium-139, PubChem CID: 166969, CAS Number: 13982-30-4
notation: 12219

C6H6Cl6 (1,2,3,4,5,6-hexachlorocyclohexane, alpha-lindane, alpha-HCH), in air
type: Concept
description: IUPAC: 1,2,3,4,5,6-hexachlorocyclohexane, PubChem CID: 727, CAS Number: 319-84-6, in gas phase
notation: 382

C5H2F10 (1,1,1,2,2,3,4,5,5,5-decafluoropentane, HFC-43-10-mee)
type: Concept
description: IUPAC: 1,1,1,2,2,3,4,5,5,5-decafluoropentane, PubChem CID: 86240, CAS Number: 138495-42-8, in gas phase
notation: 12090

C3H2F6 (1,1,1,2,3,3-hexafluoropropane, HFC-236ea)
type: Concept
description: IUPAC: 1,1,1,2,3,3-hexafluoropropane, PubChem CID: 79009, CAS Number: 431-63-0, in gas phase
notation: 557

Direction of cloud movement
type: Concept
notation: 304

C18H12 (benz(a)anthracene), in precipitation
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in precipitation
notation: 350

Meteorological Optical Range
type: Concept
notation: 525

Actinium [Ac-228]
type: Concept
description: IUPAC: actinium-228, PubChem CID: 105063, CAS Number: 14331-83-0
notation: 12233

Diffuse downward short-wave irradiance
type: Concept
description: Flux density of diffuse short-wave solar radiation, at a specified level within the atmosphere, including the Earth surface.
notation: 571

Silver [Ag-108m]
type: Concept
description: Metastable (excited) state of silver-108 isotope, IUPAC: silver-108, PubChem CID: 167088, CAS Number: 14391-65-2
notation: 12201

Transport calculations (e.g., trajectories)
type: Concept
notation: 248

Tl (thallium), TSP
type: Concept
description: IUPAC: thallium, PubChem CID: 5359464, CAS Number: 7440-28-0, in particle phase, TSP
notation: 714

Acidity-Alkalinity
type: Concept
notation: 294

C6H12 (methylcyclopentane)
type: Concept
description: IUPAC: methylcyclopentane, PubChem CID: 7296, CAS Number: 96-37-7, in gas phase
notation: 469

Scandium [Sc-46]
type: Concept
description: IUPAC: scandium-46, PubChem CID: 107673, CAS Number: 13967-63-0
notation: 12177

Atmospheric pressure
type: Concept
notation: 216

Surface ozone
type: Concept
notation: 262

C2H6 (ethane)
type: Concept
description: IUPAC: ethane, PubChem CID: 6324, CAS Number: 74-84-0, in gas phase
notation: 437

Particle light extinction coefficient
type: Concept
description: A measure of light attenuation due to scattering and absorption by aerosol particles expressed as the Beer-Lambert Law exponent at unit path distance.
notation: 12145

C8H10 (ethylbenzene)
type: Concept
description: IUPAC: ethylbenzene, PubChem CID: 7500, CAS Number: 100-41-4, in gas phase
notation: 483

Strontium [Sr-90]
type: Concept
description: IUPAC: strontium-90, PubChem CID: 5486204, CAS Number: 10098-97-2
notation: 12191

Visibility
type: Concept
notation: 230

Major inorganic components, coarse
type: Concept
description: Major inorganic components, coarse
notation: 658

C2H2Cl2 (1,1-dichloroethene)
type: Concept
description: IUPAC: 1,1-Dichloroethene, PubChem CID: 6366, CAS Number: 75-35-4, in gas phase
notation: 12113

C4H8O (butan-2-one, methylethylketone)
type: Concept
description: IUPAC: butan-2-one, PubChem CID: 6569, CAS Number: 78-93-3, in gas phase
notation: 451

Total carbon, PM10
type: Concept
description: Sum of elemental and organic carbon. Includes inorganic carbon, which is operationally distributed between elemental and organic carbon. Size range: PM10
notation: 626

C2HClF4 (1-chloro-1,2,2,2-tetrafluoroethane, HCFC-124)
type: Concept
description: IUPAC: 2-chloro-1,1,1,2-tetrafluoroethane, PubChem CID: 17822, CAS Number: 2837-89-0, in gas phase
notation: 12089

Ti (titanium), TSP
type: Concept
description: IUPAC: titanium, PubChem CID: 23963, CAS Number: 7440-32-6, in particle phase, TSP
notation: 672

Slant total delay (STD)
type: Concept
description: The time delay of a GNSS radio signal passing along an atmospheric path from transmitter to receiver compared with the same path in vacuum.
notation: 12302

C18H12 (benz(a)anthracene), in air and aerosol
type: Concept
description: IUPAC: benzo[a]anthracene, PubChem CID: 5954, CAS Number: 56-55-3, in aerosol
notation: 349

Acer
type: Concept
description: Maple pollen
notation: 12057

K+ (potassium), TSP
type: Concept
description: IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, TSP
notation: 640

NO (nitrogen monoxide)
type: Concept
description: IUPAC: nitric oxide, PubChem CID: 145068, CAS Number: 10102-43-9, in gas phase
notation: 395

Particle light absorption coefficient, PM10
type: Concept
description: 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
notation: 317

Picea
type: Concept
description: Spruce pollen
notation: 12025

Total Ericaceae
type: Concept
description: Heather family pollen
notation: 12071

Br- (bromide)
type: Concept
description: IUPAC: bromide, PubChem CID: 259, CAS Number: 24959-67-9, in total deposition
notation: 538

Tellurium [Te-131]
type: Concept
description: IUPAC: tellurium-131, PubChem CID: 6337051, CAS Number: 14683-12-6
notation: 12246

Icing potential
type: Concept
description: 3D field of super-cooled liquid water, enabling the formation of ice coating on an object.
notation: 331

Cloud optical depth
type: Concept
description: 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.'
notation: 506

Caesium [Cs-134]
type: Concept
description: IUPAC: cesium-134, PubChem CID: 6335485, CAS Number: 13967-70-9
notation: 12214

Type of low clouds
type: Concept
description: 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.]
notation: 552

Dust mass concentration
type: Concept
description: Concentration of dust or sand in the atmosphere
notation: 727

Runway visual range
type: Concept
notation: 229

C2Cl4 (tetrachloroethene)
type: Concept
description: IUPAC: 1,1,2,2-tetrachloroethene, PubChem CID: 31373, CAS Number: 127-18-4, in gas phase
notation: 275

Particle light hemispheric backscatter coefficient
type: Concept
description: The fraction of incident radiative flux scattered into all backward angles, i.e. scattering_angle exceeding pi/2 radians.
notation: 12158

c-C5H10 (cis-2-pentene)
type: Concept
description: IUPAC: (Z)-pent-2-ene, PubChem CID: 5326160, CAS Number: 627-20-3, in gas phase
notation: 496

Hygroscopic growth factor, total aerosol
type: Concept
notation: 418

C8H6 (ethynylbenzene)
type: Concept
description: IUPAC: ethynylbenzene, PubChem CID: 10821, CAS Number: 536-74-3, in gas phase
notation: 12126

C5H8 (2-methyl-1,3-butadiene, isoprene)
type: Concept
description: IUPAC: 2-methylbuta-1,3-diene, PubChem CID: 6557, CAS Number: 78-79-5, in gas phase
notation: 464

Sodium [Na-22]
type: Concept
description: IUPAC: sodium-22, PubChem CID: 6328543, CAS Number: 13966-32-0
notation: 12172

Duration of precipitation
type: Concept
notation: 211

K+ (potassium), PM2.5
type: Concept
description: IUPAC: potassium(1+), PubChem CID: 813, CAS Number: 24203-36-9, in particle phase, PM2.5
notation: 639

Cd (cadmium), PM2.5
type: Concept
description: IUPAC: cadmium, PubChem CID: 23973, CAS Number: 7440-43-9, in particle phase, PM2.5
notation: 685

Lightning discharge direction from station
type: Concept
description: Azimuth of the lightning event with respect to the corresponding station.
notation: 432

C3H6O2 (hydroxyacetone)
type: Concept
description: IUPAC: 1-hydroxypropan-2-one, PubChem CID: 8299, CAS Number: 116-09-6, in gas phase
notation: 12140

Ni (nickel)
type: Concept
description: IUPAC: nickel, PubChem CID: 936, CAS Number: 7440-02-1, in total deposition
notation: 607

Earth surface emissivity
type: Concept
description: Emissivity of the Earth surface as a function of wavelength and viewing angle.
notation: 12315

NO2- (nitrite), TSP
type: Concept
description: IUPAC: nitrite, PubChem CID: 946, CAS Number: 14797-65-0, in particle phase, TSP
notation: 653

Betula
type: Concept
description: Birch pollen
notation: 12038

SO4= (sulfate), PM10
type: Concept
description: IUPAC: sulfate, PubChem CID: 1117, CAS Number: 14808-79-8, in particle phase, PM10
notation: 621

C12H8Cl6 (aldrin), in air
type: Concept
description: 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
notation: 376

Alternaria
type: Concept
description: Alternaria spores
notation: 12084

Horizontal wind speed at specified distance from reference surface
type: Concept
description: 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.
notation: 12006

Al (aluminium)
type: Concept
description: IUPAC: aluminium, PubChem CID: 5359268, CAS Number: 7429-90-5, in total deposition
notation: 597

C14H10 (phenanthrene), in total precipitation
type: Concept
description: IUPAC: phenanthrene, PubChem CID: 995, CAS Number: 85-01-8, in total precipitation
notation: 344

Total Poaceae
type: Concept
description: Grasses pollen
notation: 12052

Mercury [Hg-203]
type: Concept
description: IUPAC: mercury-203, PubChem CID: 104771, CAS Number: 13982-78-0
notation: 12227

NH3 (Ammonia)
type: Concept
description: IUPAC: azane, PubChem CID: 222, CAS Number: 7664-41-7, in gas phase
notation: 390

Long-wave irradiance (direction unspecified)
type: Concept
description: 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.
notation: 565

Height of inversion
type: Concept
description: Height of a stable layer of air with an increased temperature.
notation: 533

Sum of Plutonium [Pu-239] and [Pu-240]
type: Concept
description: 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
notation: 12241

Rb (rubidium), PM2.5
type: Concept
description: IUPAC: rubidium, PubChem CID: 5357696, CAS Number: 7440-17-7, in particle phase, PM2.5
notation: 708