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

See stage.

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

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

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

A thermometer, invented by James Six in 1782, which simultaneously indicates the maximum and minimum temperatures attained during a given interval of time. A U-tube min/max thermometer

Lowest altitude in the atmosphere over a given location at which the air temperature is 0

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

An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. ...

A type of cistern barometer in which the level of mercury in the cistern is adjusted to the zero point of the scale before each reading.

A rain gauge which is placed under trees or foliage to determine the rainfall in that location. By comparing this catch with that from a rain gauge set in the open. the amount of rainfall which has been intercepted by foliage can be determined.

Same as water year.

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,

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

The mean difference between the readings of a given instrument and those of a standard instrument.

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

The process of modifying some characteristic of a wave (the carrier) so that it varies in step with the instantaneous value of another wave (the modulating wave) in order to transmit a message. The modified characteristic may be frequency, phase, and/or a ...

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

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

The point (physical and/or electrical) where two distinct data processing elements meet.