An addition to a rawinsonde system which allows determination of the slant range to the radiosonde.

An atmometer which uses a filter paper disc as the evaporating element. The amount of water evaporated through the paper is read at the graduated tube reservoir.

A magnetometer of the electromagnetic type which is used to measure the horizontal intensity of the earth's magnetic field.

A device, similar to a phytometer, for measuring transpiration. It consists of a small vessel containing water and sealed so that the only escape of moisture is by transpiration from a leaf, twig, or small plant with its cut end inserted in the water.

A photometer which measures the intensity of radiation as a function of the frequency (or wavelength) of the radiation.

An effect noted primarily in wet snow conditions when snow clings to the sides of a precipitation gauge and gradually accumulates until the gauge orifice is capped with accumulated snow. This effect can be minimized by using large collectors, and wind scr ...

A thermopile used in some types of radiation instruments. See solarimeter.

A forecast of the expected stage or discharge at a specified time, or of the total volume of flow within a specified Interval of time, at one or more points along a stream.

A synoptic code approved by the World Meteorological Organization in which the observable meteorological elements are encoded and transmitted in "words" of five numerical digits length. Often abbreviated synoptic code.

Winds which, over a small area, differ from those which would be appropriate to the general pressure distribution.

See photometer.

A graphical representation of stage or discharge at a point on a stream as a function of time.

A type of modulation in which the frequency of a continuous radio carrier wave is varied in accordance with the properties of a second (modulating) wave.

A line of equal or constant temperature.

A warm, dry wind on the lee side of a mountain range, the warmth and dryness due to adiabatic compression upon descent.

A hygrometer in which the rotation of the hygrometric element is a function of humidity.

A rotation anemometer which has a horizontal axis upon which helicoidal shaped vanes are mounted. See windmill anemometer.

A radiosonde which is dropped by parachute from an aircraft for the purpose of obtaining soundings of the atmosphere below.

Same as parhelion.

A seasonal wind of persistent direction, characterized by a pronounced change in direction between seasons.