Smoke Plume Rise Measurements with a Ceilometer

Smoke plume rise is an important emission property required by regional air quality models such as CMAQ in simulating the air quality effects of wildland fires. A number of smoke plume rise schemes have been developed based on the fundamental fluid dynamical equations, dimensional analysis and similarity principles, or statistical relationships of observed parameters. These schemes, however, have yet to be systematically evaluated. This study is to measure smoke plume rise of prescribed burns and applies the results to evaluating plume rise schemes. As part of a Joint Fire Science Program research project, smoke plume measurements were conducted with a ceilometer in the Southeast. A total of about 10 prescribed burns were measured during the winter and spring seasons of 2009. Measurements of the same number of burns are planned for the next year. The burn sites measured for 2009 included forests and other ecosystems in national forest park and wildlife refuge, and military bases. Burned areas ranged from hundreds to thousands of acres. The measured plume heights vary significantly from one burn to another, depending on fuel type, moisture condition, and wind. Smoke heights fluctuate over the burning period and smoke plumes touch to the ground sometimes. On the days with dense low cloud presence, smoke plumes are well capped by the clouds. The measured resulted were used to evaluate Daysmoke, a smoke plume rise model developed for prescribed burn in the South, as well as other plume rise schemes.