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

A modification of the dew cell used in radiosonde equipment.

A pressure tube anemometer, consisting of a pitot tube mounted on the windward end of a wind vane and a suitable manometer to measure the developed pressure and calibrated in units of wind.

The upward force produced by the gas in a balloon. It is equal to the free lift plus the weight of the balloon and the attached equipment.

Fine dust or salt particles dispersed through a portion of the atmosphere; a type of lithometer. The particles are so small they cannot be felt or seen with the naked eye. Many haze formations are caused by the presence of an abundance of condensation nuc ...

A method of winds aloft observation essentially the same as a pilot balloon observation except the height data is derived from the radiosonde observation rather than from assumed ascension rates.

The process by which small particles suspended in a medium of a different refractive index diffuse a portion of the incident radiation in all directions. In scattering no energy transformation results, only a change in the spatial distribution of the radi ...

A small, moveable graduated scale adjacent and parallel to the main scale of an instrument. It provides a means for interpolating between the graduations of the main scale.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

See evaporative opportunity.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

A unit of luminous intensity of a light source.

A thermometer with a muslin-covered bulb which is moistened. used to measure wet-bulb temperature.

A clockwise change in wind direction. Veering winds with height are indicative of warm air advection (WAA).

Physical equipment used in data processing. Compare to firmware, software.

Extended Binary Coded Decimal Interchange Code. A standard code used to represent data using 8 bits per character.

See bimetallic thermometer.

The component of the radiosonde which includes the modulating blocking oscillator and the radiofrequency carrier oscillator.

An aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

To free something from the binding action of ice by warming it to a temperature above the melting point of ice. Also, a warm spell when ice and snow melt.