A series of nine large-scale, open fires was conducted in the Intermou
ntain Fire Sciences Laboratory (IFSL) controlled-environment combustio
n facility. The fuels were pure pine needles or sagebrush or mixed fue
ls simulating forest-floor, ground fires; crown fires, broadcast burns
; and slash pile burns. Mid-infrared spectra of the smoke were recorde
d throughout each fire by open path Fourier transform infrared (FTIR)
spectroscopy at 0.12 cm(-1) resolution over a 3 m cross-stack pathleng
th and analyzed to provide pseudocontinuous, simultaneous concentratio
ns of up to 16 compounds. Simultaneous measurements were made of fuel
mass loss, stack gas temperature, and total mass flow up the stack. Th
e products detected are classified by the type of process that dominat
es in producing them. Carbon dioxide is the dominant emission of (and
primarily produced by) flaming combustion, from which we also measure
nitric oxide, nitrogen dioxide, sulfur dioxide, and most of the water
vapor from combustion and fuel moisture. Carbon monoxide is the domina
nt emission formed primarily by smoldering combustion from which we al
so measure carbon dioxide, methane, ammonia, and ethane. A significant
fraction of the total emissions is unoxidized pyrolysis products; exa
mples are methanol, formaldehyde, acetic and formic acid, ethene (ethy
lene), ethyne (acetylene), and hydrogen cyanide. Relatively few previo
us data exist for many of these compounds and they are likely to have
an important but as yet poorly understood role in plume chemistry. Lar
ge differences in emissions occur from different fire and fuel types,
and the observed temporal behavior of the emissions is found to depend
strongly on the fuel bed and product type.