Locations and preferred pathways of possible sources of Arctic aerosol

The chemical composition of particles collected at Alert, Northwest Territo ries, Canada, show strong, persistent seasonal variations. In a previous st udy, a 2-way/3-way mixed factor model was performed on the weekly average c oncentrations of 24 aerosol components measured over the period from 1980 t o 1991. The Multilinear Engine (ME), a new mathematical technique, was used to obtain the solution. The two modes of the 2-way model consist of the so urce composition profiles and mass contributions over the 11 yr, while for the three modes of the 3-way model, source profiles, mass contributions var iations over the weeks within a year, and the year-to-year variation over t he 11 yr within the measurement period. Five 2-way and two 3-way factors we re found to provide a good fit to the data and were easily interpreted. In this investigation, potential source contribution function (PSCF) analysis was applied to the source contributions derived from the ME analysis by inc orporating meteorological information in the form of 5-d air parcel back tr ajectories. The potential locations and/or the preferred pathways of these possible sources were then determined by the PSCF analysis. (C) 1999 Elsevi er Science Ltd. All rights reserved.