The process in which incident radiation is retained by a substance. A further process always results from absorption.

A colloquial term in western Australia for a squall, associated with thunder, on the northwest coast in summer.

A contact anemometer connected to an electrical circuit which is so arranged that the average wind speed is indicated.

A line drawn through geographical points where a given seasonal biological event occurs on the same date.

A thermometer using transducing elements which deform with temperature. Examples are the bimetallic thermometer and the Bourdon tube type of thennometer.

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.

Same as wave pole.

The state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

An instrument which automatically records the measurement of two or more meteorological elements.

The greatest distance at which it is just possible to see and recognize with the unaided eye (1) in the daytime, a prominent dark object against the sky at the horizon, and (2) at night, a known, preferably unfocused, moderately intense light source.

A conically shaped, copper rain gauge shield.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

In meteorology, an area of low pressure; a low or trough.

A wind blowing in a direction opposite to the heading of a moving object, thus opposing the object's intended progress; the opposite of a tailwind.

A colorless and odorless gaseous element. The lightest and apparently the most abundant chemical element in the universe. However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0.00005 percent by volume of dr ...

The array of indicating marks and figure in relation to which the position of an index is observed, i.e. a scale plate on a recorder.

See hydrologic accounting.

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 ...

The source of illumination for an antenna reflector. Also called antenna feed.

In a system of moist air, the ratio of the mass of water vapor to the total volume of the system. Usually expressed as grams per cubic meter (g/m3).