Wind chill index

TABLE 6.12 Wind Chill Index, WCI, Chilling Temperature, and Effect on Exposed Flesh... 

Wind chill index An empirical scale that correlates well with the sensation of bare dry skin due to the chilling effect of the outdoor air temperature and wind speed. 

But everyone felt much, much colder cos The wind chill index made it minus nine. 

Revised Wind Chill Temperature Index In 2001, the U.S. National Weather Service issued a new wind chill index. The study, conducted jointly by the U.S. and Canada,... 

Wind chill index, as its name suggests, refers to the cold environment and uses only dry bulb temperature and air velocity but takes into account the cooling effect of the wind. 

Finally, there are woik situations where the Siple and Passel (US Antarctic explorers) wind chill index may be valuable for assessing work in cold conditions. 

The combination of ambient temperature and wind speed is called windchill. Wind-chill may be used to predict the risk of freezing of the exposed skin and to predict the amount of manual dexterity decrease (Daanen, 2009). The windchill index, as an estimator of cold injury risk, is part of an ISO standard (11079, 2007). In the heat, wind has a cooling effect by enhancing convective and evaporative heat loss. 

The effects of the low air temperatures in the Transantarctic Mountains are magnified by wind which accelerates the loss of heat from the human body. This phenomenon is expressed quantitatively by the wind-chill scale (Rees 1993) that converts the measured temperature into an equivalent wind-chill temperature. For example, the arrow in Fig. 2.5a indicates that the measured air temperature of -10°C at a wind speed of 8 m/s corresponds to a wind-chill temperature of-20 C. In addition, a wind speed of 8 m/s in Fig. 2.5b is equivalent to a speed of 28.8 km/h. The wind-chill temperature also permits the definition of the discomfort index in Table 2.1. Accordingly, a wind-chill temperature of -20°C is perceived as being bitterly cold. Such conditions are not unusual during the austral sununer on the polar plateau and in the Transantarctic Mountains, except along the coast. 

Initial Wind Chill This index originally resulted from measurements of the rate of cooling of a container of water. Antarctic explorers measured the cooling power of wind at some temperature in comparison to the equivalent cooling power of still air at another temperature. The resulting equation derived from the study underestimated the time to freezing and overestimated the chilling effect of the wind. 

The equivalent chill temperature or index shows the effect that wind speed has on perceived temperature. 

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