Possible sources and preferred pathways for biogenic and non-sea- salt sulfur for the high Arctic

Sulfate is a major constituent observed in Arctic haze. Sulfur sources include anthropogenic, biogenic, and other natural sources. Previous studies have examined the concentrations and temporal variability of the concentrations of methanesulfonic acid (MSA) and sulfate (SO⁼₄) at Alert, Northwest Territories, Canada. A receptor modeling method called the potential source contribution function (PSCF) combines the concentration data for these species measured in 7-day samples continously collected between 1908 and 1991 with meteorological information in the form of air parcel back trajectories into conditional probability maps indicating the possible source areas and/or the preferred pathways that give rise to the observed high-concentration samples. -from Authors