The attenuation of light.

The interval between the lower and upper measuring limits of an instrument, i.e. a thermometer with a range of -35 to 50

Same as dropsonde.

A temperature-sensing element which converts thermal energy directly into electrical energy. In its basic form it consists of two dissimilar metallic conductors connected in a closed loop. Each junction forms a thermocouple. If one thermocouple is maintai ...

Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

The visibility along an identified runway, determined from a specified point on the runway with the observer facing in the same direction as a pilot using the runway. Compare to runway visible range.

The officially designated elevation of an airport above mean sea level, taken as the highest point on any of the runways of the airport. Same as airport elevation.

A recording weight barometer.

That portion of the atmosphere which is above the lower troposphere. Generally applied to levels above 850 mb.

A liquid-in-glass or liquid-in-metal thermometer using mercury as the liquid.

A wave disturbance in airflow due to some barrier in the flow. i.e. a hill or mountain.

Apparatus consisting of (a) standard radiosonde and radiosonde ground equipment to obtain upper-air data on pressure, temperature, and humidity, and (b) a self-tracking radio direction-finder to provide the elevation and azimuth angles of the radiosonde s ...

Wind with a speed between 48 and 55 knots (55 and 63 mph), Beaufort scale number 10.

(1) The ratio of the speeds of a chemical reaction at two temperatures differing by 10

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

The change in a performance characteristic caused by a change in a specified operating condition from reference operating condition, all other conditions being held within the limits of reference operating conditions.

A self-recording thermometer.

A halo phenomenon consisting of a horizontal circle passing through the moon, corresponding to the parhelic circle through the sun. Produced by reflection of moonlight from ice crystals.

An instrument which measures the scattering function of particles suspended in a medium in order to determine the visual range through the medium. See visibility meter.

A mercury barometer which measures atmospheric pressure by weighing the mercury in the column or cistern.