Verification of Wet Bulb Globe Temperature Index for the North Carolina ECONet

Wet bulb globe temperature (WBGT) is used widely in industry, sports, the military and other areas to indicate heat stress on humans and animals. One measurement needed for the WBGT is black globe temperature (BGT).  However, these sensors are not an essential measurement for many mesoscale networks. Due to the cost of these sensors, an algorithm developed by the National Weather Service has been designed to incorporate air temperature, relative humidity, and solar radiation to estimate black globe temperature in lieu of having an actual black globe thermometer on site. 

The North Carolina Environment and Climate Observing Network (ECONet) is a research grade mesoscale network of 40 weather stations that monitor weather data on one minute time scales. These stations have the necessary parameters needed to calculate WBGT. Three estimates of WBGT were calculated at our test facility in Raleigh, NC using a commercial black globe thermometer, a black globe thermometer developed by the NC State Climate Office, and an algorithm using temperature, relative humidity, and solar radiation. Comparison between these three methods are used to verify the robustness of the algorithm in the southeastern United States and to test the accuracy of the experimental developed sensor. Preliminary tests indicate that the experimental sensor is within 1 degree C of the commercial sensor.

Once the validation process is complete, estimated BGT values across the North Carolina ECONet are constructed. These estimation values have two purposes: 1) To validate whether the algorithm works across all locations and topographies of NC and 2) A secondhand quality control check for air temperature, relative humidity, and solar radiation.  Future work includes expanding the network of observations to create an interpolated map of near real-time WBGT values.