## Contents

Notation | Name | Description | Status |
---|---|---|---|

' | minute (angle) | Unit of plane or phase angle, accepted for use with SI: 1 ' =... | stable |

'' | second (angle) | Unit of plane or phase angle, accepted for use with SI: 1 '' ... | stable |

1 | dimensionless | Dimensionless; SI base unit equivalent: 1 | stable |

A | ampere | SI base unit of electric current | stable |

AU | astronomical unit | Unit of length, accepted for use with SI: 1 AU = 149597870700... | stable |

Bq | becquerel | SI derived unit of radioactivity; SI base unit equivalent: s-... | stable |

Bq.l-1 | becquerel per litre | Unit of radioactivity concentration; SI base unit equivalent:... | stable |

Bq.m-2 | becquerel per square metre | SI derived unit of radioactivity area concentration; SI base ... | stable |

Bq.m-3 | becquerel per cubic metre | SI derived unit of radioactivity concentration; SI base unit ... | stable |

Bq.s.m-3 | becquerel second per cubic metre | SI derived unit of time integrated radioactivity concentratio... | stable |

C | coulomb | SI derived unit of electric charge; SI base unit equivalent: ... | stable |

CFU.ml-1 | colony-forming unit per millilitre | Unit of number concentration of viable bacteria or fungal cel... | stable |

DU | Dobson Unit | Unit of column abundance of molecules in the atmosphere. 1 DU... | stable |

E | Eötvös | Unit of acceleration divided by distance,1 E = 1E-9 Gal/cm; S... | stable |

F | farad | SI derived unit of electrical capacitance; SI base unit equiv... | stable |

GHz | gigahertz | SI derived unit of frequency; SI base unit equivalent: 1E9 s-... | stable |

Gy | gray | SI derived unit of absorbed dose (of ionizing radiation); SI ... | stable |

H | henry | SI derived unit of electrical inductance; SI base unit equiva... | stable |

HU | Hazen unit | Unit of color according to the Platinum/Cobalt or Apha-Hazen ... | stable |

Hz | hertz | SI derived unit of frequency; SI base unit equivalent: s-1 | stable |

J | joule | SI derived unit of energy, work, heat; SI base unit equivalen... | stable |

J.kg-1 | joule per kilogram | SI derived unit of specific energy or specific potential enth... | stable |

J.m-2 | joule per square metre | SI derived unit of radiant exposure; SI base unit equivalent:... | stable |

K | kelvin | SI base unit of thermodynamic temperature | stable |

K.m-1 | kelvin per metre | SI derived unit of spatial gradient of temperature | stable |

K.m.s-1 | kelvin metre per second | SI derived unit of covariance of wind speed and temperature o... | stable |

K.m2.kg-1.s-1 | kelvin square metre per kilogram per second | SI derived unit of potential vorticity | stable |

MHz | megahertz | SI derived unit of frequency; SI base unit equivalent: 1E6 s-... | stable |

MPN.ml-1 | most probable number index number in 1 millilitre | Unit of expected number concentration of bacteria in the orig... | stable |

Mm-1 | per megametre | Unit of quantity with dimension of reciprocal length, e.g., o... | stable |

Mm-1.sr-1 | per megametre per steradian | SI derived unit of the scattering coefficient at a given dire... | stable |

N | newton | SI derived unit of force, weight | stable |

N.m-2 | newton per square metre | SI derived unit of pressure or equivalent quantity | stable |

NTU | nephelometric turbidity unit | Units of turbidity from a calibrated nephelometer; SI base un... | stable |

N_units | N units | Unit of atmospheric refractivity, the refractivity, N, is rel... | stable |

Ohm | ohm | SI derived unit of electrical resistance, impedance, reactanc... | stable |

Pa | pascal | SI derived unit of pressure/stress; SI base unit equivalent: ... | stable |

Pa.s-1 | pascal per second | SI derived unit of temporal derivative of pressure/stress; SI... | stable |

S | siemens | SI derived unit of electrical conductance; SI base unit equiv... | stable |

S.m-1 | siemens per metre | SI derived unit of spatial gradient of electric conductance | stable |

Sv | sievert | SI derived unit of equivalent dose (of ionizing radiation); S... | stable |

T | tesla | SI derived unit of magnetic induction, magnetic flux density;... | stable |

THz | terahertz | SI derived unit of frequency; SI base unit equivalent: 1E12 s... | stable |

V | volt | SI derived unit of voltage, electrical potential difference, ... | stable |

W | watt | SI derived unit of power, radiant flux; SI base unit equivale... | stable |

W.m-1.sr-1 | watt per metre per steradian | SI derived unit of spectral intensity, a directional quantity... | stable |

W.m-2 | watt per square metre | SI derived unit of heat flux density or irradiance; SI base u... | stable |

W.m-2.sr-1 | watt per square metre per steradian | SI derived unit of radiance; SI base unit equivalent: kg.s-3 | stable |

W.m-2.sr-1.Hz-1 | watt per square metre per steradian per hertz | SI derived unit of spectral radiance per unit frequency; SI b... | stable |

W.m-2.sr-1.cm | watt per square metre per steradian per inverse centimetre | SI derived unit of spectral radiance per unit wavenumber, wav... | stable |

W.m-2.sr-1.m | watt per square metre per steradian per inverse metre | SI derived unit of spectral radiance per inverse metre; SI ba... | stable |

W.m-3.sr-1 | watt per square metre per steradian per metre | SI derived unit of spectral radiance per unit wavelength; SI ... | stable |

Wb | Weber | SI derived unit of magnetic flux; SI base unit equivalent: kg... | stable |

a | year | Conventional unit of time duration, ranging from 365 days to ... | stable |

cb.(12h)-1 | centibar per 12 hours | Conventional unit of time derivative of pressure, pressure te... | stable |

cb.s-1 | centibar per second | Conventional unit of time derivative of pressure, pressure te... | stable |

cd | candela | SI base unit of luminous intensity | stable |

cm | centimetre | SI prefixed unit of length; SI base unit equivalent: 0.01 m | stable |

cm-3 | per cubic centimetre | SI derived unit of specific volume; SI base unit equivalent: ... | stable |

cm.h-1 | centimetre per hour | SI derived unit of speed; SI base unit equivalent: 1/360000 m... | stable |

cm.s-1 | centimetre per second | SI derived unit of speed; SI base unit equivalent: 0.01 m.s-1 | stable |

cm2 | square centimetre | SI derived unit of area; SI base unit equivalent: 1E-4 m2 | stable |

cm3.m-3 | cubic centimetre per cubic metre | SI derived unit of volumetric mixing ratio, equivalent to ppm... | stable |

d | day | Unit of time, accepted for use with SI: 1 d = 86400 s | stable |

dB | decibel | Unit of sound intensity, accepted for use with SI | stable |

dB.deg-1 | decibel per degree (angle) | Unit of angular gradient of sound intensity | stable |

dB.m-1 | decibel per metre | Unit of spatial gradient of sound intensity | stable |

dPa.s-1 | decipascal per second (microbar per second) | SI derived unit of time derivative of pressure, pressure tend... | stable |

daPa | dekapascal | SI derived unit of pressure/stress; SI base unit equivalent: ... | stable |

deg | degree (angle) | Unit of plane or phase angle, accepted for use with SI: 1 deg... | stable |

deg.s-1 | degree (angle) per second | Unit of angular speed, accepted for use with SI | stable |

deg2 | square degree (angle) | Unit of square of phase or plane angle, accepted for use with... | stable |

degC | degree Celsius (°C) | SI derived unit of temperature, as defined by ITS-90; SI base... | stable |

degC.hm-1 | degree Celsius per 100 metres | SI derived unit of spatial gradient of temperature per 100 me... | stable |

degC.m-1 | degree Celsius per metre | SI derived unit of spatial gradient of temperature per metre;... | stable |

dm | decimetre | SI prefixed unit of length; SI base unit equivalent: 0.1 m | stable |

eV | electron volt | Unit of energy, accepted for use with SI; SI base unit equiva... | stable |

fmol.kg-1 | femtomole per kilogram | SI derived unit of amount per unit mass; SI base unit equival... | stable |

ft | foot | Imperial/US unit of length, equal to 1200/3937 metre or 0.304... | stable |

g.cm-3 | gram per cubic centimetre | SI derived unit of density, equivalent to kilograms per litre... | stable |

g.kg-1 | gram per kilogram | SI derived unit of mass fraction, dimensionless; SI base unit... | stable |

g.kg-1.s-1 | gram per kilogram per second | SI derived unit of time derivative of mass fraction; SI base ... | stable |

g0 | standard acceleration due to gravity | Conventional unit of gravity acceleration; g0 = 9.80665 m.s-2 | stable |

gpm | geopotential metre | The height of a given point in the atmosphere in units propor... | stable |

h | hour | Unit of time, accepted for use with SI: 1 h = 3600 s | stable |

hPa | hectopascal | SI derived unit of pressure/stress; SI base unit equivalent: ... | stable |

hPa.(3h)-1 | hectopascal per 3 hours | SI derived unit of time derivative of pressure; SI base unit ... | stable |

hPa.h-1 | hectopascal per hour | SI derived unit of time derivative of pressure; SI base unit ... | stable |

hPa.s-1 | hectopascal per second | SI derived unit of time derivative of pressure; SI base unit ... | stable |

ha | hectare | Unit of area, accepted for use with SI: 1 ha = 1E4 m2 | stable |

in | inch | Imperial/US unit of length, equal to 25.4 millimetres | stable |

inapplicable | inapplicable | There is no value (categorical data) | stable |

kHz | kilohertz | SI derived unit of frequency; SI base unit equivalent: 1000 s... | stable |

kPa | kilopascal | SI derived unit of pressure/stress, equal to 1000 Pa; SI base... | stable |

kcal.cm-2 | kilocalory per square centimetre | Unit of radiant exposure, equal to 4.184E7 J.m-2 | stable |

kg | kilogram | SI base unit of mass | stable |

kg-2.s-1 | per square kilogram per second | SI derived unit of quantity with dimension of M-2.T-1 | stable |

kg.kg-1 | kilogram per kilogram | SI derived unit of mass fraction; SI base unit equivalent: 1 | stable |

kg.kg-1.s-1 | kilogram per kilogram per second | SI derived unit of time derivative of mass fraction; SI base ... | stable |

kg.m-1 | kilogram per metre | SI derived unit of linear mass density or quantity with dimen... | stable |

kg.m-2 | kilogram per square metre | SI derived unit of area density | stable |

kg.m-2.s-1 | kilogram per square metre per second | SI derived unit of time derivative of mass area density | stable |

kg.m-3 | kilogram per cubic metre | SI derived unit of density, mass density | stable |

km | kilometre | SI prefixed unit of length; SI base unit equivalent: 1000 m | stable |

km-1 | per kilometre | SI derived unit of quantity with dimension of reciprocal leng... | stable |

km-1.sr-1 | per kilometre per steradian | SI derived unit of the scattering coefficient at a given dire... | stable |

km.d-1 | kilometre per day | SI derived unit of speed; SI base unit equivalent: 1000/86400... | stable |

km.h-1 | kilometre per hour | SI derived unit of speed; SI base unit equivalent: 1000/3600 ... | stable |

kt | knot | Conventional unit of speed, equal to 1 nmi/h; SI base unit eq... | stable |

kt.km-1 | knot per 1000 metres | Conventional unit of spatial gradient of speed; SI base unit ... | stable |

l | litre | SI derived unit of volume; SI base unit equivalent: 0.001 m3 | stable |

lm | lumen | SI derived unit of luminous flux; SI base unit equivalent: 1 ... | stable |

lx | lux | SI derived unit of illuminance; SI base unit equivalent: cd.m... | stable |

m | metre | SI base unit of length | stable |

m(2.3-1).s-1 | metre to the two thirds power per second | SI derived unit of the quantity with dimension of L^(2/3) T-1 | stable |

m-1 | per metre | SI derived unit of quantity with dimension of reciprocal leng... | stable |

m-1.sr-1 | per metre per steradian | SI derived unit of the scattering coefficient at a given dire... | stable |

m-3 | per cubic metre | SI derived unit of specific volume | stable |

m.a-1 | metre per year | Conventional unit of velocity | stable |

m.s-1 | metre per second | SI derived unit of speed | stable |

m.s-1.km-1 | metre per second per 1000 metres | SI derived unit of spatial gradient of speed; SI base unit eq... | stable |

m.s-1.m-1 | metre per second per metre | SI derived unit of spatial gradient of speed | stable |

m.s-2 | metre per second squared | SI derived unit of acceleration | stable |

m2 | square metre | SI derived unit of area | stable |

m2.s | square metre second | SI derived unit of sea surface wave variance spectral density | stable |

m2.s-1 | square metre per second | SI derived unit of kinematic viscosity, thermal diffusivity, ... | stable |

m2.s-2 | square metre per square second | SI derived quantity with dimension of squared speed | stable |

m2.s.rad-1 | square metre second per radian | SI derived unit of sea surface wave directional variance spec... | stable |

m3 | cubic metres | SI derived unit of volume | stable |

m3.m-3 | cubic metre per cubic metre | SI derived unit of volume fraction; SI base unit equivalent: ... | stable |

m3.s-1 | cubic metre per second | SI derived unit of volume flow rate or time derivative of vol... | stable |

m4 | metre to the fourth power | SI derived unit of the second moment of area, area moment of ... | stable |

mBq.m-3 | millibecquerel per cubic metre | SI derived unit of volumetric radioactivity concentration; SI... | stable |

mGal | milligal | CGS unit of acceleration, equal to one thousandth of a Gal (1... | stable |

mS.cm-1 | millisiemens per centimetre | SI derived unit of spatial gradient of electrical conductance... | stable |

mSv | millisievert | SI derived unit of equivalent dose (of ionizing radiation); S... | stable |

mV | millivolt | SI derived unit of voltage, electrical potential difference, ... | stable |

mbar | millibar | Conventional unit of pressure, equal to 1 hPa; SI base unit e... | stable |

mg.cm-3 | milligram per cubic centimetre | SI derived unit of mass concentration; SI base unit equivalen... | stable |

mg.kg-1 | milligram per kilogram | SI derived unit of mass fraction, equivalent to ppmm (parts p... | stable |

mg.l-1 | milligram per litre | SI derived unit of density or mass concentration; SI base uni... | stable |

mg.m-3 | milligram per cubic metre | SI derived unit of density or mass concentration; SI base uni... | stable |

min | minute (time) | Unit of time, accepted for use with SI: 1 min = 60 s | stable |

missing | missing | The correct value is not readily available to the sender of t... | stable |

mm | millimetre | SI prefixed unit of length; SI base unit equivalent: 0.001 m | stable |

mm.h-1 | millimetre per hour | SI derived unit of speed; SI base unit equivalent: 1/3.6E6 m.... | stable |

mm.s-1 | millimetre per second | SI derived unit of speed; SI base unit equivalent: 0.001 m.s-... | stable |

mm3.m-3 | cubic millimetre per cubic metre | SI derived unit of volumetric mixing ratio, equivalent to ppb... | stable |

mm6.m-3 | millimetre to the sixth power per cubic metre | SI derived unit of quantity with dimension of L3; SI base uni... | stable |

mmHg | millimetre of mercury | Conventional unit of pressure, equal to 133.322387415 Pa | stable |

mmol.mol-1 | millimole per mole | SI derived unit equivalent to expressing mole fraction in par... | stable |

mol | mole | SI base unit of amount of substance | stable |

mol.mol-1 | mole per mole | SI derived unit of mole fraction; SI base unit equivalent: 1 | stable |

mon | month | Conventional unit of time duration of between 28-31 days wher... | stable |

nbar | nanobar | Conventional unit of pressure; SI base unit equivalent: 1E-4 ... | stable |

ng.kg-1 | nanogram per kilogram | SI derived unit of mass fraction, equivalent to pptm (parts p... | stable |

ng.m-3 | nanogram per cubic metre | SI derived unit of mass concentration; SI base unit equivalen... | stable |

nm | nanometre | SI prefixed unit of length; SI base unit equivalent: 1E-9 m | stable |

nmi | nautical mile | Conventional unit of length; SI base unit equivalent: 1852 m | stable |

nmol.kg-1 | nanomole per kilogram | SI derived unit of amount per unit mass; SI base unit equival... | stable |

nmol.mol-1 | nanomole per mole | SI derived unit of mole fraction; SI base unit equivalent: 1E... | stable |

okta | eights of sky covered by cloud | Unit of cloud amount, expressed as number of eighths of the s... | stable |

pH_unit | pH unit | Negative decimal logarithm of the hydrogen ion activity ('eff... | stable |

pc | parsec | Astronomical unit of length, 1 pc = 64800/Π AU | stable |

percent | per cent | Dimensionless number, expressed as a fraction of 100; SI base... | stable |

permeg | per meg | Dimensionless number, expressed as a fraction of 1000000; SI ... | stable |

permil | per mille | Dimensionless number, expressed as a fraction of 1000; SI bas... | stable |

pmol.kg-1 | picomole per kilogram | SI derived unit of amount per unit mass; SI base unit equival... | stable |

pmol.mol-1 | picomole per mole | SI derived unit equivalent of mole fraction; SI base unit equ... | stable |

ppbv | parts per billion by volume | Unit of volume fraction, equivalent to SI derived unit: 1E-9 | stable |

ppmv | parts per million by volume | Unit of volume fraction, equivalent to SI derived unit: 1E-6 | stable |

pptv | parts per trillion by volume | Unit of volume fraction, equivalent to SI derived unit: 1E-12 | stable |

psu | practical salinity unit | Conventional unit, equivalent to per mille; SI based unit equ... | stable |

rad | radian | SI derived unit of plane angle; SI base unit equivalent: 1 | stable |

rad.m-1 | radian per metre | SI derived unit of spatial gradient of plane angle | stable |

rad.s-1 | radian per second | SI derived unit of angular velocity; SI base unit equivalent:... | stable |

s | second | SI base unit of time | stable |

s-2 | per second squared | SI derived unit of second order time derivative | stable |

s.m-1 | second per metre | SI derived unit of quantity with dimension of T.L-1 | stable |

sr | steradian | SI derived unit of solid angle; SI base unit equivalent: 1 | stable |

t | tonne | Unit of mass, accepted for use with SI; SI base unit equivale... | stable |

t.ha-1 | (metric) ton per hectare | Unit of area density, equal to 0.1 kg.m-2 | stable |

u | unified atomic mass unit | Conventional unit of mass; 1 u = 1 Da (Dalton) = 1.6605390666... | stable |

uS.cm-1 | microsiemens per centimetre | SI derived unit of spatial gradient of electrical conductance... | stable |

ug.kg-1 | microgram per kilogram | SI derived unit of mass fraction, equivalent to ppbm (parts p... | stable |

ug.l-1 | microgram per litre | SI derived unit of mass concentration; SI base unit equivalen... | stable |

ug.m-3 | microgram per cubic metre | SI derived unit of mass concentration; SI base unit equivalen... | stable |

um | micrometre | SI prefixed unit of length; SI base unit equivalent: 1E-6 m | stable |

um3.cm-3 | cubic micrometre per cubic centimetre | SI derived unit of volume fraction, equivalent to pptv (parts... | stable |

umol.kg-1 | micromole per kilogram | SI derived unit of amount per unit mass; SI base unit equival... | stable |

umol.l-1 | micromole per litre | SI derived unit of amount concentration; SI base unit equival... | stable |

umol.mol-1 | micromole per mole | SI derived unit of mole fraction; SI base unit equivalent: 1E... | stable |

unknown | unknown | The correct value is not known to, and not computable by, the... | stable |

week | week | Conventional unit of time, equivalent to 604800 s | stable |