Of equal or constant pressure, with respect to either space or time.

Diffuse solar radiation which has the same intensity in all directions.

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

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 ...

See constant-level balloon.

Temperature assumed by an unsaturated air parcel when brought adiabatically to a standard pressure (1,000 mb).

An instrument for taking photographs of an image of the sun in monochromatic light.

Same as recording rain gauge.

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

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 precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

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.

A line drawn through geographical points having the same duration of sunshine (or other function of solar radiation) during a given interval of time.

Pertaining to rain, or more broadly, to precipitation.

See foehn.

A line drawn through all points on a map having the same amount of cloudiness.

A small balloon whose ascent is followed by a theodolite in order to obtain data for the computation of winds aloft.

An instrument for determining the degree of polarization of light. See photopolarimeter.

Same as precipitation-evaporation ratio.

A line drawn through points of equal humidity on given surface.