Weather and Air Quality Observations Before and During a Wildfire on Deep Organic Soils

On 5 May 2011 the Pains Bay Fire was ignited on the southern portion of the Alligator River National Wildlife Refuge in Dare County, NC. After 10 days, over 10,000 hectares had been burned, with the fire only 75% contained. It began in wetlands, but quickly spread to other fuel types on the refuge, including the pond pine-pocosin ecosystem. Not only are the above-ground fuels dense, but the below-ground organic layer is very deep, and can be very difficult to extinguish once it is ignited. Once the fire gets into the organic layer, copious amounts of smoke are emitted, and tree mortality is almost certain.

At the time of the fire ignition, we were in the third year of a 3-year project to study the relationship between meteorology, litter and duff moisture, burning characteristics and emissions from fire in deep organic soils. A portable weather station has been operating continuously in the refuge for the duration of the project, measuring moisture in the organic layer, fuel stick moisture and temperature, rainfall amount, as well as temperature, relative humidity, and wind speed and direction. After the fire was ignited, we deployed several EBAM particulate monitors downwind of the fire. We will report on the meteorological and moisture conditions leading up to the fire, as well as the observations from the air quality monitors.