Saturday, December 16, 2017

Done

“I’m done with winter…next season please.”  (Anonymous)

If you live in a place where winters are cold and snowy, chances are that you are familiar with the term “wind chill factor.” This is the temperature that a person feels across the exposed surface of skin due to the wind. For example, if a thermometer reads thirty-five degrees Fahrenheit outside and the wind is blowing at twenty--five miles per hour (MPH), the wind chill factor causes it to feel like it is eight degrees Fahrenheit. In other words, your ninety-eight degree body loses heat as though it is eight degrees outside.

The term “wind chill” originated with American explorer and geographer Paul Siple and his fellow explorer Charles Passel made the first breakthroughs in this research while on an expedition in the Antarctic in 1940. Siple and Passel suspended bottles of water outside a hut at their base station and measured how long it took the water to freeze under various wind conditions. After taking hundreds of these readings, the pair had a good idea of how rapidly heat was lost at different wind speeds.

The coldest wind chill ever recorded on Earth was -192 degrees Fahrenheit at a remote weather station in Vostok, Antarctica in 2005. The high temperature that day was -99 degrees, and wind gusts reached up to 113 MPH, resulting in the -192 degree wind chill. Try riding a motorcycle in that!
Wind doesn't actually reduce temperature at all. The temperature isn't actually causing any temperature to drop. It only feels like it is to humans because of the body's physical response to cold. By constantly blowing away the heat the body generates, convection (the transfer of heat by flowing air) creates the sensation of being colder than it actually is.

Fighting wind chill comes down to two components: insulation layers to slow the rate at which body heat is lost, and wind proofing to prevent rushing air from stealing that heat away. If something is wet, and wind is passing over it, the evaporative effect can drop the actual temperature of the object. When you get out of a pool on a hot day and a breeze hits you and makes you feel cold.  This is not wind chill, but rather the chilling effect of evaporation.

Wind chill is only an attempt by science to describe the sensation of cold on the skin. It's not an actual unit of measurement, and it varies from person to person depending on their tolerance to cold, what they are wearing, and even the level of moisture in the air.[i]

“It’s so cold my hot flashes are starting to feel kind of good.” (Billie on Maxine Cartoons)



[i] Sources used:
·        “How Does the Wind Chill Factor Work?” (https://science.howstuffworks.com/nature/climate-weather/atmospheric/question70.htm)
·        The Wind Chill Myth” by Aaron Cortez

·        “Wind Chill Facts” by Rayman

 

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