Sources of Fine Particle Concentration and Composition in Northern Vermont

摘要

This study applies and compares results of four receptor modeling techniques to a common set of IMPROVE-like, speciated fine particle measurement data collected at remote site in northwestern Vermont between 1988 and 1995. Two multivariate mathematical models - Positive Matrix Factorization and UNMIX - were applied to the measurement data, and identified seven “common” sources, which have similar compositions and similar fine mass contributions in both models. Two ensemble backward trajectory techniques - Potential Source Contribution Function and Residence-Time Analysis - are also applied to evaluate and interpret the mathematical model results. The trajectory techniques indicate a strong regional character to the upwind locations associated with high contributions identified independently by the mathematical techniques. These convergent results among the multiple methods provide a degree of confidence that each of the receptor methods can provide useful insights for air quality management, when applied to speciated fine particle data of this nature. Midwestern fuel combustion (with separate seasonal source characteristics), local Woodsmoke, and East Coast urban source influences collectively accounted for nearly 90% of the average fine mass concentrations at the receptor. Smaller contributions were also identified from Canadian Smelters, Canadian motor vehicles (and/or other Mn sources), and windblown soil.