Same as Aeolian.

An accumulation of granular ice tufts on the windward sides of exposed objects that is formed from supercooled fog or cloud and built out directly against the wind.

An anemometer which measures wind speed by means of the properties of wind-borne sound waves. It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus t ...

Thermodynamic change of state of a system in which there is transfer of heat across the boundaries of the system. Compare to adiabatic process.

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

A rocket designed primarily for routine upper air observations in the lower 250,000 feet of the atmosphere, especially that portion inaccessible to balloons (above 100,000 feet).

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 meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

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 ...

Same as atmometer.

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

Force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

A photoelectric spectrophotometer which is used in the determination of the ozone content of the atmosphere.

Same as atmometer.

A feeble oscillatory disturbance of the earth's crust, detectable only by very sensitive seismographs. Certain types of microseisms seem to be closely correlated with pressure disturbances. See microbarm.

See mote.

The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.