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sion system 2. the prevention of electri-
cal interference of a radio signal suppressor /s.pres./ noun a device used in an electrical or electronic sys-tem to reduce unwanted currents, e.g. a resistor or grid . A suppressor improves the quality of the signal.
surface /sf.s/ noun 1. an outer cov-ering of something, or the top part of something . the surface of the wing 2. the Earth’s surface or ground
surface air temperature /sf.s e. tempr.t../ noun the temperature recorded in the shade at a height just above ground level
surface front /sf.s frnt/ noun a
weather front at the surface of the earth
. The cirrus cloud can be 900 miles ahead of the surface front with a rain belt as wide as 200 miles.

surface heating /sf.s hit../
noun the heating of the ground by the
sun surface movement radar noun a type of radar used at airports to monitor aircraft traffic on the ground. Abbrevia-tion SMR
surface synoptic chart /sf.s s. n.pt.k t.ɑt/ noun a chart of a geo-graphical area with symbols, fronts and isobars giving a representation of the weather over the area at a particular time

surface tension /sf.s ten.(.)n/
noun the tension of the surface film of a liquid
surface wind /sf.s w.nd/ noun a
wind which blows across the land sur-
face surge /sd/ noun a sudden increase in something such as electrical power . engine surge instability in the power output of an engine . verb to move with force like a wave . If combustion pres-sure increases above compressor outlet pressure, the airflow will reverse in direction and surge forward through the compressor.
surplus /spl.s/ adjective excess, more than is needed . Fuel penalties can be incurred if fuel surplus to requirements is carried.
surround /s.raυnd/ noun something which encloses or borders . The design of windows, hatches or door surrounds is very critical. . verb to encircle or to enclose . The Earth is surrounded by the atmosphere.
surveillance /s.ve.l.ns/ noun the
act of watching or monitoring
surveillance radar /s.ve.l.ns re.dɑ/ noun primary radar scanning, often through 360°
survey noun /sve./ a detailed examination . An aerodrome meteoro-logical office maintains a continuous survey of meteorological conditions over the aerodromes for which it is des-ignated to prepare forecasts. . verb /s.
ve./ to determine the boundaries, area, or elevations of land by means of meas-uring angles and distances . Take care when using wooded areas to fix position because the cutting down of trees may have led to a change in shape since the map was made.
survival /s.va.v(.)l/ noun the fact of remaining alive after an accident . The survival of passengers in the sea depends on rapid location and rescue.