Overview article published in the Bulletin
of the American Meteorological Society September
issue
Overview
The FireFlux
campaign was designed to collect in situ measurements of the wind and
temperature fields associated with a fast moving, wind-driven grass fire.
The experiment was conducted in a 150 acre tall grass coastal prairie and
consisted of a head fire ignited upwind of instrumentation placed within and
downwind of the fuel bed. Instrumentation used to measure the atmospheric
interactions at the fire front included two micrometeorological towers (43
and 10 m in height) used to measure heat, water vapor and CO2
fluxes, two SODARS, radiosonde and tethersonde balloon systems, IR digital
video and various digital photographic systems for time-lapse photography.
Rate of spread was estimated to be between 0.7 to 1.3 m s-1 and
ambient winds at 2 m AGL were about 3 m s-1. The FireFlux
experiment took place at the University of Houston Coastal Center in
Texas on 23 February 2006.
Experiment Design and Instrument Placement
Map of instrument layout and design. While
dashed line north of towers is the ignition line.
Infrared video imagery of ignition
Fire front approaching 43 m meteorological tower
Measurements of Fire-Induced Winds during the Fire Front
Passage
Time series of
1-s averaged data from 2 m sonic anemometer on main tower. Wind speed is
indicated by the blue line in panel (a), and wind direction by black dots.
The vertical velocity, w, is shown in panel (b) and blue crosses are the
instantaneous 20 Hz tilt corrected values, and solid black line is 1-s
averaged data. Panel (c) shows fine-wire thermocouple temperatures (Tc) as
red line. The convergence zone is indicated by the red horizontal arrow
labeled CZ (panel a) and the region of downdrafts is indicated in panel b
with a small red arrow.
