ICE CORE RECORDS OF CONTINENTAL DUST, SEA SALT, BIOMASS BURNING, AND POLLUTION FROM MCCALL GLACIER, ALASKA DURING THE PAST TWO CENTURIES

McCall Glacier is a climate sensitive valley glacier in the Brooks Range of Alaska that has recorded both regional and local climate information for the past two centuries. We present and discuss comprehensive, high-resolution records of a range of aerosol-related elements and chemical species measured in a 152 m deep ice core from the upper cirque of McCall Glacier. Fundamental to our interpretation is a new, nearly annually resolved age scale for the ice core. These novel records indicate that McCall Glacier faithfully documents regional climate signatures including influences of the Pacific Decadal Oscillation and recent regional warming. Tracers for dust and sea salt point to an increasing component of local dust and sea salt deposition since the end of the Little Ice Age which likely are the result of sea ice retreat in the Arctic Ocean and ice/snow retreat around the Brooks Range, Alaska since the end of the Little Ice Age. Indicators of industrial emissions and biomass burning show pronounced changes since the dawn of the Industrial Revolution. We use comparisons to an array of similar records from Greenland and northeastern Canada, as well as atmospheric transport modeling to investigate potential sources.