Atmospheric Deposition to the Arctic Ocean: Concentrations of Dissolved Trace Elements in Melt Ponds During US GEOTRACES Western Arctic Section

At high latitudes, the rise in temperature during spring and summer leads to the formation of melt ponds in depressions upon the surface of sea ice. These transitory features provide an environment in which trace elements supplied by atmospheric deposition can be retained for several weeks before they are released to the surface ocean by break-up of the sea ice. As a result they represent a potentially important but poorly understood opportunity for the modification of trace element speciation between atmospheric deposition and input to the surface ocean. The US Arctic GEOTRACES cruise of summer 2015 sought to advance understanding of the magnitude and speciation of trace element inputs to the Arctic Ocean, with atmospheric deposition identified as an important input pathway. Here we present initial results from the analysis of dissolved trace elements (Fe, Al, Zn, Mn, Cd, Cu, Co) in melt ponds sampled at several stations during that cruise. The melt ponds studied showed varying degrees of connection to the underlying surface ocean, with salinities ranging between 1.4 and 23.2.