A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

A recording anemometer.

In general, any self-recording instrument carried aloft by any means to obtain meteorological data.

Same as marine rainbow.

In meteorology, a deflecting force acting on a body in motion and resulting from the earth's rotation. It deflects air currents to the right in the northern hemisphere and to the left in the southern hemisphere, thus having an effect on wind direction.

A type of photoelectric photometer used to measure high-altitude winds on the assumption that stellar scintillation is caused by atmospheric inhomogeneities being carried along by wind near the tropopause level.

See wind vane.

The succession of stages through which water passes on the ground and in the atmosphere: evaporation from land or bodies of water, condensation to form clouds, precipitation, accumulation in the soil or in bodies of water, and re-evaporation.

Upwarddirected solar radiation, reflected by the earth's surface and the atmosphere.

Negative Vorticity Advection.

See evaporation pan.

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

Abbreviation for precipitation-evaporation quotient.

A device for measuring the river stage. Also called stream gauge.

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

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

A device used to switch electrical current at a selectable setpoint temperature.

The lowest value of a measured quality at which a sensor meets its accuracy specification.

A set of electrical conductors, often on a backplane, that carry data and power signals among the various components of a computer.

Electromagnetic radiation of shorter wavelength than visible radiation but longer than x-rays, between 0.02 and 0.4 micron (200 and 4000 angstrom).