An instrument for measuring the difference between incoming and outgoing terrestrial radiation.

The actual time during which physical events take place.

A pyrheliometer of the thermoelectric type. Radiation is allowed to fall on two concentric silver rings, the outer covered with magnesium oxide and the inner covered with lamp black. A system of thermocouples (thermopile) is used to measure the temperatur ...

Complementary Metal-Oxide Semiconductor. A method of making silicon chips that results in low power consumption by the circuits.

A buoyant balloon rising freely in the atmosphere, as opposed to a captive balloon.

A remote indicator for wind speed and direction used in conjunction with a contact anemometer and a wind vane. The indicator consists of a center light, connected to the contact anemometer, surrounded by eight equally spaced lights which are individually ...

An instrument, dropped from high attitude and carried by a stable parachute. used to measure the vertical component of turbulence aloft.

A device which converts energy from one form into another, i.e. an ac generator transducer which converts the mechanical motion of anemometer cups into an electrical signal.

Old snow that has become granular and compacted as a result of melting and refreezing.

An instrument for measuring the difference of the solar radiation falling on both sides of a horizontal surface from the whole hemisphere.

Thermodynamic change of state of a system in which there is transfer of heat across the boundaries of the system. Compare to adiabatic process.

The minimum temperature shown by a minimum thermometer exposed in an open situation with its bulb at the level of the tops of the grass blades of short turf.

A feeble oscillatory disturbance of the earth's crust, detectable only by very sensitive seismographs. Certain types of microseisms seem to be closely correlated with pressure disturbances. See microbarm.

The condition of the atmosphere when the amount of water vapor present is the maximum possible at the existing temperature.

A forecast of weather elements of particular interest to aviation; including ceiling, visibility, upper winds, icing, turbulence, precipitation types, and storms.

Same as wave pole.

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

Name sometimes used in place of pyranometer as a generic term.

The direction from which the wind is blowing, measured in points of the compass or in azimuth degrees.

A thermometer using transducing elements which deform with temperature. Examples are the bimetallic thermometer and the Bourdon tube type of thennometer.