Quantifying the relationship between atmospheric transport and the chemical composition of precipitation on Bermuda

Abstract

A cluster analysis of atmospheric trajectories was performed to identify periods of similar transport. Data were stratified into a warm (April-September) and a cool (October-March) season. Relative to the cool season, significantly higher per event concentrations of non-seasalt sulfate and nitrate occurred in the warm season on Bermuda. There was no significant difference in the per event precipitation amount between seasons; however, there was significantly higher per event deposition of warm season non-seasalt sulfate, and nitrate. During the cool months, 40% of the deposition occurred with transport from the west, off the East Coast of the US, implicating anthropogenic sources. In the warm season, an equally large fraction of deposition was associated with flow from the Bahamas region, suggesting an oceanic source of biogenic sulfur as the precursor. -from Authors