Atmosphere And Weather

What Wind Chill is



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For many, the worst days of the winter are the ones with significant wind. In such days, it is perceived that it feels much colder than a day where the wind is absent, although the temperature readings on both days remain the same. The perceived reduction in the temperature as a result of the wind is given the name, ‘wind chill factor.’ While there are many ways to calculate the wind chill factor, this article will elaborate on the scientific basis of ‘wind chill’ based on several examples obtained from day-to-day life.

Defining ‘wind chill

With regard to the term ‘wind chill,’ or ‘wind chill factor,’ it should be known that it is not defined at temperatures higher than 10 degrees Celsius, and the resulting perceived temperature would not be higher than the air temperature at any time. This means that a person who feels a difference due to perceived skin temperature would always perceive a lower temperature than the temperature recorded in the air. However, if the air temperature were measured in windy and non-windy conditions, the measured readings would not be different as a result of presence or absence of the wind.

Cause for ‘wind chill’

The reason for the wind chill is the acceleration of convection heat loss from the surface of the skin as a result of continuous flow of air over the same surface. The convection heat loss would make the skin cooler and therefore give rise to a much colder feeling than the prevailing air temperature. However, this would subside as the person moves to a place where there is wind cover even though the air temperature remains the same.

Examples and uses

In day-to-day life, we use the wind chill phenomenon to cool down things faster than they would usually take. For instance, one could blow air over the soup to cool down the soup, as it will accelerate the process of heat loss through convection. In another instance, if one places a glass filled with hot water in a place exposed to outside air and to the wind it would cool down much faster than when the same glass is placed in the same outside temperature when the air movement is at a standstill. However, none of the glasses would get colder than the outside air temperature even with a windy environment.

As mentioned in the beginning, calculating the wind chill factor would involve complex formulae. However, many different factors could affect the perceived chilliness during windy conditions, in which clothes play a major role. Therefore, the formulae used to calculate the wind chill would do so in the absence of other such interferences towards the perceived chilliness.

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