See radiosonde commutator.

The actual lifting force of an inflated balloon, usually expressed in grams.

Generally, a measure of the departure of the mean daily temperature from a given standard, one degree day for each degree (

Transmitted energy which is modulated in order to carry information. Usually, it is in the form of a radio- frequency sine wave, modulated either in amplitude or in frequency.

A curve showing the variation of temperature with height in the free air. See lapse rate.

An absolute instrument developed by K. Angstrom for the measurement of direct solar radiation. The radiation receiver station consists of two identical manganin strips whose temperatures are measured by attached thermocouples. One of the strips is shaded, ...

Thermometer for measuring the temperature in the soil at different depths.

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

The amount of precipitation falling in one day, or other specified period, that is likely to be equalled or exceeded in any given place only once in a century. That is, a precipitation amount that has a return period of 100 years.

The ratio of the amount of electromagnetic radiation reflected by a body to the amount incipient upon it, commonly expressed as a percentage. The albedo is to be distinguished from the reflectivity, which refers to one specific wavelength.

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

An instrument, for the recording of two or more meteorological parameters, in which the ventilation is provided by a suction fan.

See ceilometer.

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 temperature scale with the ice point at 273 degrees and boiling point of water at 373 degrees. It is intended to approximate the Kelvin temperature scale with sufficient accuracy for many sciences, notably meteorology.

A unit of mass numerically equal to the molecular weight of the substance. The gram-mote or gram-molecule is the mass in grams numerically equal to the molecular weight, i.e. a gram-mole of oxygen is 32 grams.

A psychrometer in which the ventilation is provided by a suction fan.

Same as precipitation- effectiveness index.

A set of weekly colored rainbow arcs sometimes discernable inside a primary rainbow.