80 likes | 99 Views
CSU Atmospheric Science Department National Park Service/CIRA Carnegie Mellon University USDA/FS Fire Science Lab. Characterizing impacts of wild and prescribed fires on ambient fine particle concentrations. Fire and smoke.
E N D
CSU Atmospheric Science Department National Park Service/CIRA Carnegie Mellon University USDA/FS Fire Science Lab Characterizing impacts of wild and prescribed fires on ambient fine particle concentrations
Fire and smoke • Fire is a large emitter of carbon to the atmosphere in many parts of the world • In the U.S., OC contributes 1/3 or more to PM2.5 in much of the SE and west • Fire thought to be a major contributor • Increased fire expected to produce 40% increase in PM2.5 OC in western U.S. by middle of century deltaOC due to fire (2046-2050 minus 1996-2000) Spracklen et al., 2009
Particle Source Markers • How do we apportion fine particle pollution to its sources? • Molecular Markers = Source Tracers • Candidate Markers • K+ • Levoglucosan Marker as fraction of smoke particle Smokeparticle Levoglucosan
The FLAME Experiments • Fire Science Lab at Missoula • CSU, NPS, USFS, EPA, DRI, CMU, CU, Aerodyne,… • Characterization of smoke emissions • Hundreds of burns • NW, SW, and SE fuel emphasis
What happens when smoke ages? • Aging chamber experiments • How much new PM (SOA) is produced by aging? • Can we find SOA tracers? • What happens to primary smoke tracers?
Summary • Levoglucosan a useful marker for primary PM from biomass combustion • Source profiles determined for many fuel types and components (FLAME I,II,III) • Less fire phase dependent than K+ • Photochemical decay of levoglucosan can bias estimates of primary smoke PM low • New PM production in aging fire plumes highly variable • Mass increase sometimes small as SOA production appears offset by fragmentation and volatilization • Single marker unlikely to fully capture PM production during aging Levoglucosan Levoglucosan
Aging example: black spruce AMS time series: Black Spruce (10/07/09) Aging figures courtesy of Chris Hennigan