|Affiliation(s)||PI||Project period||Funded by|
|DAS||Obrist, Daniel||07/01/2010 - 06/30/2012||USDA - Forest Service|
The goal of this study is to develop and use a specific characterization method to differentiate between particulate matter (PM) contributions in the Lake Tahoe basin from residential wood combustion, wildfires, and prescribed fires. Deposition of PM is an important source of phosphorus (P) and sediment to Lake Tahoe, and leads to reductions in water clarity and decreases atmospheric visibility in the basin. The relative importance of PM emissions from various types of biomass combustion-i.e., domestic wood combustion, wildfires, and prescribed fires-is mainly based on seasonal observations without direct confirmation by measurements. We propose to develop a method to specifically characterize PM emissions from domestic wood combustion, wildfires, and prescribed fire emissions by combining two of the most commonly used biomass combustion tracers, soluble potassium (K+) and levoglucosan, with detailed characterization of organic compounds (i.e., carbohydrates, anhydrosugars, lignin), and particulate-bound mercury (Hg). These chemical PM fingerprints are expected to provide a powerful tool for differentiation of PM emissions from different biomass combustion sources-including in-basin versus out-of-basin contributions-and will possibly also allow for evaluation of past fire history in the basin in soil and sediment records.