A self-recording psychrometer.

Graduated fixed stake used in regions of abundant snowfall to facilitate the measurement of snow depth.

A unit of luminance or brightness equal to 1/d candles per foot'.

An instrument for taking photographs of an image of the sun in monochromatic light.

A line drawn through points of equal humidity on given surface.

A pressure tube anemometer, consisting of a pitot tube mounted on the windward end of a wind vane and a suitable manometer to measure the developed pressure and calibrated in units of wind.

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.

Same as geostrophic wind level.

Same as precipitation-evaporation ratio.

A unit of illuminance or illumination equal to one lumen per foot'. This is the illuminance provided by a light source of one candle at a distance of one foot.

The line-of-sight distance between two objects.

A reversing thermometer which is encased in a strong glass outer shell that protects it against hydrostatic pressure. Compare to unprotected thermometer.

modulated radiosonde-A radiosonde which transmits the indications of the meteorological sensing elements in the form of pulses spaced in time. The meteorological data are evaluated from the intervals between the pulses. Also called timeinterval radiosonde ...

Radiation with wavelengths greater than 4 microns. (In meteorology, same as infrared radiation.)

Temperature assumed by an unsaturated air parcel when brought adiabatically to a standard pressure (1,000 mb).

Apparatus from which the nature and time of precipitation may be determined.

A small balloon whose ascent is followed by a theodolite in order to obtain data for the computation of winds aloft.

Generally, the relative states of inflow, outflow, and storage of moisture over a given area of earth's surface.

Line drawn through geographical points recording equal amounts of precipitation during a given time period or for a particular storm.

A scale of yellows, greens, and blues for recording the color of sea water, as seen against the white background of a Secchi disk.