A mercury barometer in which the tube is U-shaped and the upper and lower mercury surfaces have the same diameter.

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

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

An instrument for rapidly obtaining samples of airborne dust; a type of dust counter. Particles pass through a cylindrical chamber, are drawn at high velocity through a narrow slit, and then impinge upon a microscope cover glass located a short distance f ...

Same as rain gauge.

Nested Grid Model generated every 12 hours by NCEP.

In thermodynamics, the integrating factor of the differential equation referred to as the first law of thermodynamics, In statistical mechanics, a measure of translational molecular kinetic energy (with three degrees of freedom). In general, the degree of ...

A wave resulting from the action of wind on a water surface.

An instrument consisting of a series of graduated cylinders possessing selective collection efficiencies. It is used for the measurement of quantities relating to the size distribution of cloud droplets.

Tables prepared from the psychrometric formula and used to obtain vapor pressure, relative humidity, and dew point from values of wet-bulb and dry-bulb temperatures.

Air in motion relative to the surface of the earth. Almost exclusively used to denote the horizontal component.

An instrument for the measurement of the radon content of the atmosphere.

Operation mode of a communication circuit in which one end can only transmit and the other end can only receive.

A recording hair hygrometer.

Downward-facing pyranometer used for measuring reflected solar radiation.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

Apparatus using the combined simultaneous action of a bimetallic thermometer and a hair hygrometer to move a needle in front of a divided scale. fts construction permits dew point variations to be indicated approximately.

Thermometer used for measuring the lowest temperature attained during a given interval of time, for example, a day.

A radiosonde which is dropped by parachute from an aircraft for the purpose of obtaining soundings of the atmosphere below.

A line drawn through all points on a map having the same amount of cloudiness.