Award: PLR-1460290

In the Arctic, the atmospheric deposition of numerous species, including contaminant elements (e.g. Hg, Pb, Se) is significant. This input has implications for the ecosystem, and even human health. However measurements of deposition rates in the Arctic are rare and difficult to execute; we simply cannot "be there" to sample flux in a routine manner. This is further complicated by existence of different catchments (snow/ice/meltponds/ocean) resulting in elements following circuitous paths within the ecosystem. We used the cosmic ray produced radioisotope, 7Be, to trace the atmospheric deposition of elements within the Arctic water/ice/snow system, and linked aerosol concentrations to flux. Seawater, ice, snow, melt pond, and aerosol samples were collected during late summer 2011 as part of the German Icebreaker RV Polarstern's ARK-XXVI/3 campaign. 7Be (T1/2= 53.3d) is particularly well suited for studying the deposition of chemical species into the Arctic as the inventory of 7Be, as partitioned between the ice/ocean, is a direct measure of its rate of atmospheric input to these catchments. We used the inventory and distribution of 7Be within the water column, ice, snow, and melt ponds to trace the partitioning and pathways of elements input through atmospheric deposition within the Arctic system. Coupled with the 7Be and trace element concentration of aerosols, estimates of the atmospheric depositional flux of trace elements (TEs) were also derived. The combination of a tracer (7Be) immune to anthropogenic contamination and the strong seasonality of regional anthropogenic aerosol contributions provide insight not only into the amount and timing of TE deposition into the Arctic, but also into the partitioning and uptake of elements in the Arctic ecosystem, illuminating how TE deposition will change as sea ice conditions in the Arctic evolve in the future. A PhD student, Ben Galfond (UM), an undergraduate student at FSU (Brian Kilgore), and a post-doctoral research associate at FSU (Rachel Shelley), were involved in various aspects of cruise preparation, cruise participation, sampling, analysis, and data interpretation for this project. Last Modified: 09/01/2017 Submitted by: David C Kadko