General term for any device that measures precipitation: principally a rain gauge or snow gauge.

Radiation coming from the solid angle of the sun's disc, as opposed to diffuse sky radiation, effective terrestrial radiation, or radiation from any other source. Direct solar radiation is measured by pyrheliometers.

A measure of the intrinsic luminous intensity emitted by a source in a given direction. Luminance is a measure only of light. The comparable term for electromagnetic radiation in general is radiance.

A measure of the degree to which the weather or climate of a region is favorable to the process of evaporation. Usually considered to be the rate of evaporation. under existing atmospheric conditions, from a surface of water which is chemically pure and h ...

Read Only Memory. A memory that cannot be altered in normal use of a computer, Usually used to store information permanently, such as firmware programs.

The volume of liquid water evaporated per unit area in unit time. usually measured as the depth of liquid water lost per unit time from the whole area.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

The change in barometric pressure within a specified period of time (typically 3 hours for meteorological observations).

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

Electromagnetic radiation lying in the wavelength interval between 0.8 micron and I millimeter. At the lower limit of this interval, the infrared radiation spectrum is bounded by visible radiation, while on its upper limit it is bounded by microwave radia ...

A line drawn through geographical points having the same pluvial index.

A high-altitude sounding system consisting of a small solid- propellant research rocket carried aloft by a large plastic balloon. The rocket is fired near the maximum altitude of the balloon flight.

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.

Rate of flow of water past a point in a stream, expressed as volume per unit time, i.e. cubic feet per second.

meter-An instrument for measuring the transmissivity of the atmosphere; a type of transmissometer. It consists of a constant- intensity collimated light source located at a suitable distance from a photoelectric cell. Variation in the turbidity of the atm ...

A technique for making winds aloft observations in which two theodolites located at either end of a baseline follow the ascent of a pilot balloon. Synchronous measurements of the elevation and azimuth angles of the balloon. taken at periodic intervals, pe ...

Same as ombrometer.

An accumulation of granular ice tufts on the windward sides of exposed objects that is formed from supercooled fog or cloud and built out directly against the wind.