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IUPUI PROFESSOR HELPS DEVELOP NEW WIND CHILL FORMULA
FOR U.S. AND CANADA

INDIANAPOLIS - People will have a better idea of how cold it feels outside this winter thanks to the work of IUPUI professor Maurice Bluestein.

Bluestein and Randall Osczevski, a Canadian physicist, have revised the current wind chill formula at the request of the U.S. National Weather Service and the Meteorological Services of Canada. The previous formula has long been considered flawed in producing wind chills that are too cold. The new formula raises wind chills, depending on the wind speed, by up to 20 degrees.

The National Weather Service anticipates the new system will take effect this November.

Bluestein maintains there were many flaws in the original calculation of the wind chill done more than 50 years ago where researchers used a can of freezing water in the Antarctic. Instead of using a can of water, Bluestein and Osczevski used a model of the human face and studied 12 volunteers who walked on a treadmill in varying temperatures and wind speeds.

The original wind chill uses wind speeds measured at 33 feet above ground and Bluestein and Osczevski felt that it should be measured at the average human face height of five feet. They also incorporated modern heat transfer theory, lowered the speed at which the wind is considered calm, and used a consistent standard for the skin's resistance to heat loss.

Bluestein hopes that with a more accurate formula, people will take the wind chill more seriously. "We've had people in the past who've thought 'Okay, it can't be that cold,' and ignored it," he said. "It makes it safer that they can depend on the wind chill."

This winter the two researchers will begin incorporating the effect of the sun on the wind chill. After that is completed, they will tackle the heat index.

Bluestein began his research on the wind chill in 1995 after shoveling snow in his daughter's driveway and thinking that it did not feel as cold as the wind chill indicated. After publishing several papers, he was invited to participate in a group of organizations, including several federal agencies, interested in revising the wind chill. The group selected Bluestein's model and Osczevski's model of a new wind chill as a starting point and asked them to work together this summer to create a new formula for the U.S. and Canada. Bluestein is an associate professor of mechanical engineering technology at the Purdue School of Engineering and Technology at IUPUI.

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