check chamber-A chamber use to check the sensing elements of radiosonde equipment.

Determination of the total amount of snow covering a watershed or a given region. Both depth and water content of the snow may be measured, and the results may be used to predict the amount of water that will be available after melting.

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

An instrument of the aspiration condenser type which measures the concentration and mobility of small ions.

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

The process whereby a position on the scale of an instrument is identified with the magnitude of the signal (or input force) actuating the instrument.

Wind with a speed between 22 and 27 knots (25 and 31 mph); Beaufort scale number 6.

A wave resulting from the action of wind on a water surface.

A unit of luminance (or brightness) equal to 1/6 candles per square centimeter.

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

An instrument for measuring the extinction coefficient in water.

In general. the severe wind of an intense tropical cyclone (hurricane or typhoon). The term has no further technical connotation, but, unfortunately, is easily conftlsed with the strictly defined hurricane-force wind,

A sudden, significant increase in station pressure.

Small particle on which water vapor condenses.

The maximum distance along the runway at which the runway lights are visible to a pilot at touchdown. Runway visual range may be determined by an observer located at the end of the runway, facing in the direction of landing, or by means of a transmissomet ...

A hypothetical, ideal body which absorbs completely all incident radiation. independent of wavelength and direction. No actual substance behaves as a true black body, although platinum black and other soots rather closely approximate this ideal. However, ...

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

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

Same as fogbow.

The rising of cold water from the deeper areas of the ocean to the surface. This phenomena often occurs along the California coast during the spring and summer.