Biogeochemical Cycling of Dissolved Zinc in the Western Arctic (Arctic GEOTRACES GN01) Academic Article uri icon

abstract

  • AbstractThe biogeochemical cycling of dissolved zinc (dZn) was investigated in the Western Arctic along the U.S. GEOTRACES GN01 section. Vertical profiles of dZn in the Arctic are strikingly different than the classic nutrienttype profile commonly seen in the Atlantic and Pacific Oceans, instead exhibiting higher surface concentrations (~1.1nmol/kg), a shallow subsurface absolute maximum (~46nmol/kg) at 200m coincident with a macronutrient maximum, and low deep water concentrations (~1.3nmol/kg) that are homogeneous (sp.) with depth. In contrast to other ocean basins, typical inputs such as rivers, atmospheric inputs, and especially deep remineralization are insignificant in the Arctic. Instead, we demonstrate that dZn distributions in the Arctic are controlled primarily by (1) shelf fluxes following the sediment remineralization of high Zn:C and Zn:Si cells and the seaward advection of those fluxes and (2) mixing of dZn from source waters such as the Atlantic and Pacific Oceans rather than vertical biological regeneration of dZn. This results in both the unique profile shapes and the largely decoupled relationship between dZn and Si found in the Arctic. We found a weak dZn:Si regression in the full water column (0.077nmol/mol, r2=0.58) that is higher than the global slope (0.059nmol/mol, r2=0.94) because of the shelfderived halocline dZn enrichments. We hypothesize that the decoupling of Zn:Si in Western Arctic deep waters results primarily from a past ventilation event with unique preformed Zn:Si stoichiometries.

published proceedings

  • GLOBAL BIOGEOCHEMICAL CYCLES

altmetric score

  • 3.1

author list (cited authors)

  • Jensen, L. T., Wyatt, N. J., Twining, B. S., Rauschenberg, S., Landing, W. M., Sherrell, R. M., & Fitzsimmons, J. N.

citation count

  • 23

complete list of authors

  • Jensen, LT||Wyatt, NJ||Twining, BS||Rauschenberg, S||Landing, WM||Sherrell, RM||Fitzsimmons, JN

publication date

  • March 2019