Meteorology

Meteorology

A database of terms pertaining to the scientific study of the atmosphere.

Contributors in Meteorology

Meteorology

A measure of the length of the path through the atmosphere to sea level traversed by light rays from a celestial body, expressed as a multiple of the pathlength for a light source at the zenith. It ...

Opposition

Weather; Meteorology

In astronomy, the arrangement of the earth, sun, and one of the other planets or the moon, in which the angle subtended at the earth between the sun and the third body, in the plane of the ecliptic, ...

Minimums

Weather; Meteorology

The limiting values of ceiling, visibility and wind, or runway visual range, established as safety minimums for aircraft landings and takeoffs. Civil aircraft operate under limits stated in Civil Air ...

Optical meteor

Weather; Meteorology

A rarely used term describing any of the phenomena of meteorological optics, such as a halo, rainbow, or mirage.

Optical mass

Weather; Meteorology

The vertical integral of the density of absorbers between two altitudes; used mainly in determining the transmission through an absorbing gas. Dimensions are mass per unit area (e.g., kg m −2 ).

Optical hygrometer

Weather; Meteorology

Same as spectral hygrometer; a group of hygrometers based on the spectral attenuation of radiation by specific water vapour absorption lines or bands.

Optical depth

Weather; Meteorology

The optical thickness measured vertically above some given altitude. Optical depth is dimensionless and may be used to specify many different radiative characteristics of the atmosphere. See aerosol ...