| Wildland fires cause the loss of life and billions of dollars in property damage every year in the US annually thus, there is a need to better understand, predict, and manage both wildland and prescribed fires. Moisture released from combustion, in addition to added heat, can enhance buoyancy and convection, influencing fire behavior. Previous studies have shown a wide range of smoke plume moisture enhancement, but much uncertainty still exists in the quantitative values of moisture released during combustion. In this study, three measurement platforms were used to obtain in situ measurements of temperature and relative humidity during various prescribed fires near the fire front and aloft. Stationary and non-stationary measurement platforms used were towers equipped with temperature and relative humidity probes, radiosondes, and a radio controlled (RC) airplane with a radiosonde installed in the wing. The goal of this study is to better quantify moisture of wildland fire smoke plumes. Water vapor concentration varied within the smoke plume from the surface and aloft.Water vapor captured by the radiosondes aloft was less than that obtained by the towers at the fire front, as a result of ambient air entraining into the smoke plume at higher levels. Tower and radiosonde results show smoke plume moisture enhancement ranged between 1.0 to 19.1 g kg-1 and 0.3 to 2.5 g kg-1, respectively. Smoke plume moisture enhancement captured by the RC airplane is on the order of 0.5 to 4.3 g kg-1, in agreement with the tower data from the same burn. |
