data obtained simultaneously over a wide area for
presenting a comprehensive picture of the state of
the atmosphere over a given period of time.
T
TACAN—Tactical air navigation, a radio aircraft
navigation aid used originally by the military to
provide a pilot with direction and distance to a
TACAN transmitter.
TIC—Type, intensity, character code used to describe
frontal systems.
TRANSMISSOMETER—Any device used to
measure the transmission of light through a
medium.
TROUGH—(Sometimes spelled TROF) An elongated
area of low atmospheric pressure or heights
extending outward from a low center; the opposite
of a ridge. Also, the lowest portion of a wave cycle;
the dip between the wave crests.
U
UHF—Ultra--high frequency radio transmission.
UNREP—Underway replenishment.
UPS—Universal polar stereographic grid system used
by the military to locate positions in the polar
regions.
UTC—Coordinated Universal Time, usually suffixed
with a "Z."
UTM—Universal transverse mercator coordinates; a
military coordinated system based on .a series of
grids used to locate positions between 84°N and
80°s.
V
VALID—Effective, good.
VEERING—A change in the wind direction in a
clockwise manner in the Northern Hemisphere, or a
counterclockwise manner in the Southern
Hemisphere.
VELOCIMETER—In general, a device used to
measure velocity (speed). In oceanography, the
sound velocimeter measures the speed of sound in
water.
VERTREP—Vertical replenishment by use of
helicopters.
VLF—Very--low frequency.
W
WAN—Wide area network.
WBC—Weather broadcast center.
WBGT—Wet--bulb globe temperature, a combined
reading of air temperature, wet--bulb temperature,
and a temperature inside a black--colored metal
(high heat absorbing) ball.
WEATHER—The state of the atmosphere with respect
to its effect upon life and human activities.
WEFAX—An acronym for weather facsimile,
specifically the NWS service providing satellite
imagery and graphic products via a geostationary
satellite data broadcast.
WMO—World Meteorological Organization.
WPM—Words per minute.
X
XBT—Expendable bathythermograph, usually refers
to the probe that is dropped in the water and not
recovered.
XSV—Expendable sound velocimeter, usually refers to
the probe that is dropped in the water and not
recovered.
AI-5
