A type of pressure-tube anemometer, named after the inventor.

A momentary decrease in the speed of the wind.

The downward flux of atmospheric radiation passing through a given level surface, usually taken as the earth's surface. This result of infrared (long-wave) absorption and reemission by the atmosphere is the principal factor in the greenhouse effect.

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.

The record of an aneroid barograph.

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

Precipitation composed of balls or irregular lumps of ice with diameters between 5 and 50 mm.

The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.

A relatively small-scale, upward moving current of air.

A thermometer designed for use in measuring the temperature of sea water. One form consists of a mercury-in-glass thermometer protected by a perforated metal case. Another form consists of a mercury-in-glass thermometer surrounded by a metal case which fo ...

A Sunshine recorder of the type in which the time scale is supplied by the motion of the sun. The instrument, which is pointed at the celestial pole, consists of a hemispherical mirror mounted externally on the optical axis of a camera. The lens of the ca ...

An increase in the central pressure of a pressure system; opposite of a deepening. More commonly applied to a low rather than a high.

The cardinal points of the compass, i.e. north, south, east, west.

General name for an instrument which measures the earth's magnetic field intensity.

An instrument for measuring the extinction coefficient in water.

A hypothetical temperature characterized by a complete absence of heat and defined as 0 K, -273.15 C, or -459.67 F.

A definite portion of a stream channel, commonly taken between two gauging stations, but may be taken between any two specified points.

An instrument which automatically records the voltage applied to it, as a function of time.

Not a linear function of the relevant variables.

The statement that the viscosity of air is independent of the density of air.