A momentary decrease in the speed of the wind.

A mercury barometer in which the tube is U-shaped and the upper and lower mercury surfaces have the same diameter.

Very small precipitation drops (diameters less than 0.5 mm) that appear to float with air currents while falling in an irregular path. Unlike fog droplets, drizzle falls to the ground.

The process by which one object becomes adhered to another by the binding action of ice.

A thermograph in which ventilation is provided by a suction fan.

Winds from the four cardinal points of the compass; that is, north, east, south, and west winds.

A rainbow seen in the spray of the ocean. It is optically the same phenomenon as the ordinary rainbow.

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

Instrument used to measure the amount of water evaporated from the soil surface during a given time interval.

The envelope of air surrounding the earth and bound to it more or less permanently by virtue of the earth's gravitational attraction. The system whose chemical Properties. dynamic motions, and physical processes constitute the subject matter of meteorolog ...

A recording hair hygrometer.

The inaccuracy that the manufacturer permits when the unit is calibrated in the factory.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

A graphical aid used in fire weather forecasting to calculate the degree of forest-fire danger (or burning index). Commonly in the form of a circular slide rule, the firedanger meter relates numerical indices of (a) the seasonal stage of foliage, (b) the ...

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

A radar which is used to obtain the azimuth elevation, and slant range of an airborne target.

An instrument for measuring the ultraviolet in solar and sky radiation.

A clock-driven instrument mounting which automatically and continuously points in the direction of the sun. It is used with a pyrheliometera,hen continuous direct solar radiation measurements are required.

Random Access Memory. The memory of a computer which can be read and written into at any location without passing through preceding locations.

See river basin.