wind chill

wind chill
Still-air temperature that would have the same cooling effect on exposed skin as a given combination of temperature and wind speed.

As the wind speed increases, the wind chill equivalent temperature decreases; e.g., an air temperature of 30 °F (–1.1 °C) with a wind speed of 20 mph (32.2 kph) produces a wind chill of 17 °F (–8 °C). Wind chill is often included in weather reports to describe how cold it feels.

Matching a specific air temperature (columns) with a wind speed (rows) will show the wind chill ...

Encyclopædia Britannica, Inc.

* * *

also spelled  windchill , also called  wind chill factor 
 a measure of the rate of heat loss from skin that is exposed to the air. It is based on the fact that, as wind speeds increase, the heat loss also increases, making the air “feel” colder. Wind chill is usually reported as a “wind chill temperature” or “wind chill equivalent”—that is, the temperature under calm air at which heat loss would be equal to the loss actually being experienced because of higher wind speeds. For example, as is shown in the Celsius wind chill chart—>, a temperature of −25 °C (−13 °F) in calm air would have a wind chill temperature equal to the actual air temperature. Under these conditions, exposed skin would freeze in 30 minutes. At a wind speed of 40 km (25 miles) per hour, however, the wind chill temperature would be −41 °C (−42 °F), and skin would freeze in less than 10 minutes.

      Wind chill indices, the formulas and assumptions used to calculate wind chill temperatures, have varied over the years. For the second half of the 20th century, weather forecasts (weather forecasting) in North America commonly used the Siple-Passel index, based on wind speeds measured by an anemometer 10 metres (33 feet) above the ground. During the winter of 2001–02, the U.S. National Weather Service (see also weather bureau) and the Meteorological Service of Canada introduced a new index based on heat lost from the exposed faces of 12 volunteers in a chilled wind tunnel. Calm air is considered to have winds of 5 km (3 miles) per hour or less. Clear night sky conditions are assumed, eliminating any warming effect of the Sun.

* * *

Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • wind|chill — wind chill, or wind|chill «WIHND CHIHL», noun. the combined cooling effect on the human body of air temperature and wind speed. If the air temperature is 10 °F and the wind speed is 10 mph, the estimated wind chill is ―9°F …   Useful english dictionary

  • wind chill — [ˈwınd tʃıl] n [U] technical the cooling effect of the wind ▪ It must have been minus 5 with the wind chill factor …   Dictionary of contemporary English

  • Wind Chill — Wind Chill, est un film américano britannique d épouvante réalisé par Gregory Jacobs, sorti en 2007. Sommaire 1 Synopsis 2 Fiche technique 3 Distribution 4 …   Wikipédia en Français

  • Wind Chill — o Sensación Térmica del Viento es una película de terror de 2007 protagonizada por Emily Blunt y Ashton Holmes. George Clooney y Steven Soderbergh están entre los productores del proyecto. La película fue dirigida por Gregory Jacobs, quien… …   Wikipedia Español

  • wind chill — [ wınd ,tʃıl ] noun uncount the fact that the wind makes the air temperature feel colder …   Usage of the words and phrases in modern English

  • wind chill — ► NOUN ▪ the cooling effect of wind on a surface …   English terms dictionary

  • Wind chill — This page is for the meteorological effect of wind chill. For the film, see Wind Chill. Wind chill is the apparent temperature felt on exposed skin, which is a function of the air temperature and wind speed. The wind chill temperature (often… …   Wikipedia

  • wind chill — noun : the cooling effect of moving air on a body expressed as the amount of heat lost per unit area per unit of time and taking into account both temperature and wind speed * * * wind chill noun 1. The cooling effect that wind has as it blows on …   Useful english dictionary

  • Wind Chill — This page is for the movie Wind Chill. For the term, see wind chill.Infobox Film name = Wind Chill caption = Promotional movie poster for the film imdb id = 0486051 writer = Joe Gangemi Steven A. Katz starring = Emily Blunt Ashton Holmes Chelan… …   Wikipedia

  • wind chill factor — wind chill ,factor noun singular a measurement of the air temperature in a particular place that includes the effect that the wind speed has on how cold you feel …   Usage of the words and phrases in modern English

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”