Apparatus designed to measure the amount of precipitation falling in the form of snow. The device determines the weight of the snow or the volume of water after the snow melts.

See radiation shield.

Atmospheric layer throughout which there is no change of temperature with height, i.e. a zero lapse rate.

A sudden, significant increase in station pressure.

Snow shower, particularly of a very light and brief nature.

Instrument used to measure the amount of water evaporated from the soil surface during a given time interval.

Psychrometer to which a small chain or rotary handle is attached so that the observer can rotate the instrument rapidly to properly ventilate the thermometer bulbs.

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

Contraction for pilot balloon observation.

Snow gauge composed of a metal cylinder, closed at one end, used to obtain a sample of snow from which the water is measured after melting.

The processing of the form or mode of a signal so as to make it intelligible to, or compatible with, a given device.

A large plastic constant-level balloon for duration flying at very high altitudes.

Radiation with wavelengths less than 4 microns.

An aneroid barometer with a scale graduated in altitude instead of pressure units.

An element that can control current without moving parts, heated filaments, or vacuum gaps.

An instrument for measuring differences in electric potential.

The amount of moisture which, if available, would be removed from a given land area by evapotranspiration. Expressed in units of water depth.

A cone-tipped metal rod designed to be driven downward into deposited snow or firn. The measured amount of force required to drive the rod a given distance is an indication of the physical properties of the snow or firn.

In a radiosonde observation, a level (other than a standard level) for which values of pressure, temperature, and humidity are reported because temperature and/or humidity data at that level is sufficiently important or unusual to warrant the attention of ...

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.