Major solutes, metals, and alkylated aromatic compounds in high-latitude maritime snowpacks near the trans-Alaska pipeline terminal, Valdez, Alaska

The chemical constituents within a snowpack can provide information about the atmosphere through which the snow was deposited. Valdez is located in south-central Alaska and has a high-latitude maritime climate, with annual snowfall typically exceeding 8 m within the city limits. Valdez is also the termination point of the trans-Alaska pipeline system, where tankers are loaded with crude oil from the North Slope of Alaska. Integrated samples of the top 1 m of snow were collected at seven sites near Valdez and analyzed for major solutes, lead, and alkylated aromatic compounds, in particular benzene, toluene, ethylbenzene, and xylene (BTEX). For comparison, sites were also sampled near Juneau, Alaska, which has a similar climate but no petroleum transport infrastructure. Major solute chemistry at all sites was dominated by chloride and was consistent with a marine air mass source of ions in precipitation. Sulfate levels in Valdez were typically on the order of 10 μeq l−1 and significantly higher than found in Juneau snow. Other major solute levels were low in Valdez and Juneau. Lead levels were below detection limits for all sites, with the exception of trace concentrations (<0.4 μg l−1) reported at two Valdez locations. Alkylated organics were present at all Valdez locations, at levels similar to those documented previously in urban locations. No alkylated organics were detected in Juneau snowpacks.