Apparatus from which the nature and time of precipitation may be determined.

A device for computing certain psychrometric data, usually the dew point and the relative humidity, from known values of the dry-bulb and wet-bulb temperatures and the atmospheric pressure. One type is the circular slide-rule form and, like the psychromet ...

A thermometer based upon the principle that the velocity of a sound wave is a function of the temperature of the medium through which it passes. Sonic thermometers possess very short time-constants and eliminate radiation error.

The scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface. In terms of the hydrologic cycle, the ...

Temperature assumed by an unsaturated air parcel when brought adiabatically to a standard pressure (1,000 mb).

The point (physical and/or electrical) where two distinct data processing elements meet.

Any conventional barometer fitted with an extended scale so that atmospheric pressure measurements may be made at both high and low altitudes.

See constant-level balloon.

See stage.

A warm, dry wind on the lee side of a mountain range, the warmth and dryness due to adiabatic compression upon descent.

An evaporation pan in which the evaporation is measured from water in a pan floating in a larger body of water.

A hygrometer in which the rotation of the hygrometric element is a function of humidity.

Same as recording rain gauge.

A magnetometer of the electromagnetic type which is used to measure the horizontal intensity of the earth's magnetic field.

A graphical representation of stage or discharge at a point on a stream as a function of time.

Diffuse solar radiation which has the same intensity in all directions.

Of equal or constant pressure, with respect to either space or time.

A faintly-colored circular arc similar to a rainbow but formed on fog layers containing drops whose diameters are 100 microns or less. Also called mistbow, white rainbow.

Lowest altitude in the atmosphere over a given location at which the air temperature is 0

The temperature at which all three phases of a substance can exist in equilibrium. This temperature occurs at only one pressure. The triple-point of water is 273.16 K and is the basis of the Kelvin scale.