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: