CHARACTERIZING IMPACTS OF WILD AND PRESCRIBED FIRES ON AMBIENT FINE PARTICLE CONCENTRATIONS CSU Atmospheric Science Department National Park Service/CIRA Carnegie Mellon University USDA/FS Fire Science Lab

Fire and smoke o Fire is a large emitter of carbon to the atmosphere in many parts of the world o In the U.S., OC contributes 1/3 or more to PM 2.5 in much of the SE and west o Fire thought to be a major contributor o Increased fire expected to produce 40% increase in PM 2.5 OC in western U.S. by middle of century deltaOC due to fire ( minus ) Spracklen et al., 2009

Particle Source Markers o How do we apportion fine particle pollution to its sources? o Molecular Markers = Source Tracers o Candidate Markers o K+ o Levoglucosan Smoke particle Marker as fraction of smoke particle 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

Yosemite source apportionment

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?

Levoglucosan 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

Aging example: black spruce AMS time series: Black Spruce (10/07/09) Aging figures courtesy of Chris Hennigan