HOPKINS GLOSSARY OF WEATHER TERMS W
water vapor channel
- The distance between successive maxima (crests) or minima
(troughs) of a wave train, measured along the direction of wave
propagation. The wavelength is one of the ways used to identify
wave phenomena. Wavelength units are units of distance, such
as micrometers or meters.
- The final temperature attained by the wetted muslin covered
wet bulb thermometer of a psychrometer when thoroughly
ventilated. The lowest temperature that an air parcel would have
if cooled adiabatically to saturation at constant pressure by
evaporation of water into it, assuming that all latent heat
required for evaporation would be supplied by the air parcel
itself. The units for wet bulb temperature are the same for air
temperature. Contrast with dry-bulb temperature.
wet-bulb thermometer (or wet-bulb)
- The thermal sensor in a psychrometer that has a muslin
covered bulb which is saturated with water and then ventilated
thoroughly to attain the wet-bulb temperature. Contrast
with dry-bulb thermometer.
- Air in motion relative to the earth's surface, caused by the
average movement of a "large number" of molecules of
air, usually with scales larger than the random motions of individual
molecules; often refers only to the horizontal motion because
vertical wind components, especially near the earth's surface
are relatively small.
- The wind profiler is an array of Doppler
radar units that measures and displays wind information
(wind speed and direction) from the earth's surface up to an altitude
of 16 km. These instruments are generally used to detect low
level wind shear.
- The difference between wind velocity measured at two
specific locations divided by the distance between those two positions;
wind shear consists of a combination of speed shear and
- Any instrument designed primarily to measure wind direction
- A vector quantity that describes wind motion in terms
of wind speed and wind direction.
Last update 6 June 1996
Edward J. Hopkins, Ph.D.
Department of Atmospheric and Oceanic Sciences
University of Wisconsin-Madison