Monitoring CO, PM2.5, CO2 from low-intensity fires for the development of modeling tools for predicting smoke dispersion

This field study provides validation and support for the development of modeling tools for predicting smoke dispersion from low-intensity fires (Joint Fire Science Program grant # 09-1-04-1 and #09-1-04-2). Smoke models rely on measurements of PM2.5, carbon monoxide (CO), and CO2 as analogs for smoke. We will present the atmospheric monitoring results from the grid of four tall towers (10m, 20m, 30m, 10 m control) and twelve short towers (3m) placed inside and outside the fire perimeter for a 265 acre low intensity prescribed burn on March 20, 2011 at Butler Place, in the Pine Barrens of New Jersey. Placing air quality PM2.5 monitors within the fire would be risky and prohibitively expensive. An array of inexpensive, expendable, fast response and low power CO sensors, based on carbon monoxide transducers from residential alarms was designed and built to provide a spatial grid over the wide range of CO concentrations expected within the fire. In addition, particulate monitors based on smoke detector technology (UCB sensor, EME Systems) were deployed, having shown a good correlation with PM2.5. Inexpensive CO2 monitors were also incorporated into the equipment. These low cost CO monitors, the modified smoke particulate monitors, and CO2 analyzers were tested against reference PM2.5 monitors and CO2 monitors at prescribed fires in Calloway Forest, NC and the New Jersey Pine Barrens in 2010 and 2011. Response times, sensitivity, range of measurements and differences between the smoke monitoring / air quality sensors are discussed. Overall, results from the array of inexpensive CO and PM sensors within the burn yielded very good, consistent results in comparison to the more expensive air quality PM2.5 monitors, and showed the complex spatial and temporal dynamics within the burn.