Wind with a speed between 7 and 10 knots (8 and 12 mph), Beaufort scale number 3.

A unit of power equal to one joule per second or 10' ergs per second.

A self-recording thermometer.

The depth of water that would result from the melting of snow or ice, assuming measurement on a horizontal surface and no infiltration or evaporation.

Force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

A systematic summary of the terms (inflow, outflow, and storage) of the storage equation as applied to the computation of soil-moisture changes, ground-water changes, etc. An evaluation of the hydrologic balance of an area. Also called basin accounting, w ...

A motorlike device containing a rotor and a stator and capable of converting an angular position into an electrical signal, or an electrical signal into an angular position. When several synchros are correctly connected, all of the rotors will align thems ...

See mote.

An instrument for rapidly obtaining samples of airborne dust; a type of dust counter. Particles pass through a cylindrical chamber, are drawn at high velocity through a narrow slit, and then impinge upon a microscope cover glass located a short distance f ...

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

An element that can control current without moving parts, heated filaments, or vacuum gaps.

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

An anemometer which measures wind speed in terms of the drag which the wind exerts on a solid body. See bridled-cup anemometer, normal-plate anemometer, pendulum anemometer.

A direct-vision nephoscope constructed in the following manner: A grid-work of bars is mounted horizontally on the end of a vertical column and made free to rotate about the vertical axis. The observer rotates the grid and adjusts his or her position unti ...

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

A thermometer used in aircraft which automatically corrects for adiabatic and frictional temperature rises by imparting a rotary motion to the air passing the thermal sensing element.

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

The smallest change in the environment that causes detectable change in the indication of an instrument. Compare to sensitivity.

In radiometry, a measure of the intrinsic radiant intensity emitted by a radiator in a given direction.

Same as precipitation- effectiveness index.