A device used on certain types of instruments to prevent unwanted radiation from affecting the measurement of a quantity. Also called solar radiation shield.

Pertaining to the action or effect of the wind. Derived from the name of the Greek god of the winds, Aeolus.

The mass density of a parcel of air expressed in units of mass per volume.

A unit of pressure used principally in oceanography. One decibar (10' dynes/cm2) equals 0.1 bar. In the ocean, hydrostatic pressure in decibars very nearly equals the corresponding depth in meters.

An instrument used to measure changes in the level of the water in an evaporation pan. The gauge is normally placed in a Stillwell and adjusted so that the point of the hook just breaks the water surface. The change in water level is read on the attached ...

A photometer that measures the received intensity of a distance tight source.

Same as photometer.

Closed, curved, flexible tube of elliptic cross section which is deformed, according to type, by variations of atmosphere spheric pressure or temperature and so provides a measurement of the particular parameter.

Generally, the relative states of inflow, outflow, and storage of moisture over a given area of earth's surface.

A type of recording siphon barometer. The mechanically magnified motion of a float resting on the lower mercury surface is used to record atmospheric pressure on a rotating drum.

The center of an area of high pressure, usually accompanied by anticyclonic and outward wind flow. Also known as an anticyclone.

An approximation to the complete equations describing atmospheric motion in which only the terms most important for the growth and decay of synoptic scale extratropical weather systems (i.e., the large areas of high and low pressure seen on weather maps) ...

Anemometer whicb measures wind speed by measuring the degree of cooling of a metal wire heated by an electric current. A type of cooling power anemometer.

See ceilometer.

Particle on which the freezing of water occurs.

The depth of water that would result from the melting of snow or ice, assuming measurement on a horizontal surface and no infiltration or evaporation.

A type of photoelectric photometer used to measure high-altitude winds on the assumption that stellar scintillation is caused by atmospheric inhomogeneities being carried along by wind near the tropopause level.

A thermometer consisting of a clock mechanism the speed of which is a function of temperature.

Growth of a cloud or precipitation particle by the collision and union of a frozen particle with a super-cooled water drop.

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.