The outer, solid portion of the earth: the crust of the earth.

A measure, proposed by Angstrom, of the precipitation effectiveness of a region.

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

A photometric unit of illuminance or illumination equal to one lumen per square centimeter.

The most common of the principal rainbow phenomena, which appears as an arc of about 42

A numbering system using a base number of 2 and having only two digits: 0 and 1. The fundamental system of representing information with electrical pulses.

A component of the wind (often using Cartesian coordinates. i.e. X and Y wind vectors). Also, an arrow representing wind velocity, drawn to point in the direction of the wind and with a length proportional to wind speed.

See river basin.

Wind with a speed between 11 and 16 knots (13 and 18 mph); Beaufort scale number 4.

The intensity (flux per unit solid angle) of visible radiation weighted to take into account the variable response of the human eye as a function of the wavelength of light. Usually expressed in candles.

A computed characteristic of a particular river basin, expressed as the time difference between the time-center of mass of rainfall and the time-center of mass of resulting runoff.

The process by which events in the real world are translated into machine-readable signals.

The minimum temperature shown by a minimum thermometer exposed in an open situation with its bulb at the level of the tops of the grass blades of short turf.

A hygrometer in which the sensitive element is a strand or strands of human hair, the length of which is a function of the relative humidity of the air.

An instrument which indicates the presence of dust particles in the atmosphere. Also spelled coniscope.

Turbulence encountered by aircraft when flying through air space devoid of clouds. Thermals and wind shear are the main causes.

Same as atmometer.

Formation of a single water drop by the union of two or more colliding drops.

modulated radiosonde-A radiosonde which transmits the indications of the meteorological sensing elements in the form of pulses spaced in time. The meteorological data are evaluated from the intervals between the pulses. Also called timeinterval radiosonde ...

A general term for atmospheric water in any of its forms, i.e. clouds, fog, hail, ice crystals, rain.