Vocabulary

Atmospheric State - Surface Meteorology

Atmospheric conditions.

Specific Measurements:



Atmospheric moisture: The moisture content of the air as indicated by several measurements including relative humidity, specific humidity, dewpoint, vapor pressure, water vapor mixing ratio, and water vapor density; note that precipitable water is a separate type.

Atmospheric pressure: The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the "column" of air lying directly above the point in question.

Atmospheric temperature: The temperature indicated by a thermometer exposed to the air in a place sheltered from direct solar radiation.

Atmospheric turbulence: High frequency velocity fluctuations that lead to turbulent transport of momentum, heat, mositure, and passive scalars, and often expressed in terms of variances and covariances.

Extreme event time: The time of extreme meteorological events such as min/max temperature and wind gusts.

Horizontal wind: The horizontal wind in terms of either speed and direction, or the zonal (u) and meridional (v) components.

Hydrometeor Geometry: Measurements describing the geometry of hydrometeors, e.g. oblateness, diameters along different axes, volume, etc.

Hydrometeor Size Distribution: The number of hydrometeors observed in a given size range.

Precipitation: All liquid or solid phase aqueous particles that originate in the atmosphere and fall to the earth's surface.

Vertical velocity: The component of the velocity vector, along the local vertical.

Visibility: The greatest horizontal distance in a given direction at which it is just possible to see and identify with the unaided eye (a) in the daytime, a prominent dark object against the sky at the horizon, and (b) at night, a moderately intense light source.

 

Radiometric terms for the IASOA data vocabulary are taken from the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) program’s measurement vocabulary. For the full reference, please visit: http://www.arm.gov/measurements.

Radiometric - Longwave Broadband

Diffuse and direct radiant energy.

Specific Measurements:


Longwave broadband downwelling irradiance: The total diffuse and direct radiant energy, at wavelengths longer than approximately 4 µm, that is being emitted downwards.


Longwave broadband net irradiance: The difference between upwelling and downwelling broadband longwave radiation.

 

Longwave broadband upwelling irradiance: The rate at which radiant energy, at a wavelength longer than approximately 4 µm, is being emitted upwards into a radiation field and transferred across a surface area (real or imaginary) in a hemisphere of directions.

 

Radiative heating rate: The heating rate due to the divergence of long and shortwave radiative flux.


Net broadband total irradiance: The difference between upwelling and downwelling, covering longwave and shortwave radiation.

 

Radiometric terms for the IASOA data vocabulary are taken from the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) program’s measurement vocabulary. For the full reference, please visit: http://www.arm.gov/measurements.

Radiometric - Shortwave Broadband

All of the solar radiation, across the wavelength range of 0.4 and 4 µm.

Specific Measurements:



Radiative heating rate: The heating rate due to the divergence of long and shortwave radiative flux.

Net broadband total irradiance: The difference between upwelling and downwelling, covering longwave and shortwave radiation.

Shortwave broadband diffuse downwelling irradiance: All of the solar radiation, across the wavelength range of 0.4 and 4 µm, coming directly from the sky except for solar radiation coming directly from the sun and the circumsolar irradiance within approximately three degrees of the sun.

Shortwave broadband direct downwelling irradiance: Radiant energy, across the wavelength range of 0.4 and 4 µm, that is transferred directly from the sun to the receiver.

Shortwave broadband direct normal irradiance: The rate at which radiant energy in broad bands of wavelengths shorter than approximately 4µm, that comes directly from the Sun without being scattered or absorbed in the atmosphere, passes through a unit area perpendicular to the direction from the Sun.

Shortwave broadband radiance: A measure of the intrinsic radiant energy flux intensity, at wavelengths between 0.4 and 4 µ, emitted by a radiator in a given direction, expressed in units of energy per unit time per unit solid angle.

Shortwave broadband total downwelling irradiance: The total diffuse and direct radiant energy that comes from some continuous range of directions, at wavelengths between 0.4 and 4 {mu}m, that is being emitted downwards.

Shortwave broadband total net irradiance: The difference between upwelling and downwelling broadband shortwave radiation.

Shortwave broadband total upwelling irradiance: The rate at which radiant energy, at a wavelength between 0.4 and 4 {mu}m, is being emitted upwards into a radiation field and transferred across a surface area (real or imaginary) in a hemisphere of directions.

 

Radiometric terms for the IASOA data vocabulary are taken from the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) program’s measurement vocabulary. For the full reference, please visit: http://www.arm.gov/measurements.

Aerosol - Optical

The effects of aerosols on radient energy and light scattering.

Specific Measurements:



Actinic flux: The quantity of light in the atmosphere available to molecules at a particular point and which, on absorption, initiates photochemical processes in the atmosphere (spectral spheradiance) actinic flux units: (quanta or photons) / ( m2 nm s )

Aerosol absorption: The process in which radiation energy is retained by aerosols.

Aerosol backscattered radiation: The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray.

Aerosol extinction: The removal of radiant energy from an incident beam by the process of aerosol absorption and/or scattering.

Aerosol optical depth: A measure of how much light aerosols prevent from passing through a column of atmosphere.

Aerosol optical properties: The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter fraction.

Aerosol scattering: The scattering of radiative energy by processes at the aerosol and molecular level.

Backscatter depolarization ratio: The ratio of cross polarized to co-polarized elastic backscatter.

Backscattered radiation: The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray.

 

Radiometric terms for the IASOA data vocabulary are taken from the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) program’s measurement vocabulary. For the full reference, please visit: http://www.arm.gov/measurements.

Pages