wind chill temperature index
- wind chill temperature index
(WCTI)
a measurement of the combined cooling effect of low air temperature and wind on the human body. The index was first defined by the American Antarctic explorer Paul Siple in 1939. As originally used by U.S. meteorologists, the wind chill index (WCI) was computed from the temperature T (in °F) and wind speed V (in mi/hr) using the formula: WCI = 0.0817(3.71 sqrt(V) + 5.81 - 0.25V)(T - 91.4) + 91.4.
In 2001, U.S. and Canadian meteorologists agreed on a revised definition of the wind chill temperature index (WCTI). The U.S. version, with the temperature in °F and wind speed in miles per hour, is WCTI = 35.74 + 0.6215T - 35.75V0.16 + 0.4275TV0.16.
The Canadian formula, with temperatures in °C and wind speed in km/h, is
WCTI = 13.12 + 0.6215T - 11.37V0.16 + 0.3965TV0.16.
A chart is provided. The new formula gives higher temperatures, but these temperatures, unlike the old WCI numbers, are supported by clinical experiments.
Dictionary of units of measurement.
2015.
Look at other dictionaries:
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