Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 12, issue 5
Biogeosciences, 12, 1373–1385, 2015
https://doi.org/10.5194/bg-12-1373-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 12, 1373–1385, 2015
https://doi.org/10.5194/bg-12-1373-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 04 Mar 2015

Research article | 04 Mar 2015

Diatom flux reflects water-mass conditions on the southern Northwind Abyssal Plain, Arctic Ocean

J. Onodera1, E. Watanabe1, N. Harada1, and M. C. Honda2 J. Onodera et al.
  • 1Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Natsushima-cho 2-15, Yokosuka 237-0061, Japan
  • 2Department of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology, Natsushima-cho 2-15, Yokosuka 237-0061, Japan

Abstract. We studied time-series fluxes of diatom particles from 4 October 2010 to 18 September 2012 using bottom-tethered moorings with two sediment traps deployed at 180 and 1300 m depths at Station NAP (75° N, 162° W; 1975 m water depth) in the western Arctic Ocean. This paper discusses on the relationship of time-series diatom fluxes to satellite-based sea-ice motion and simulated hydrographic variations. We observed clear maxima of the diatom valve flux in November–December of both 2010 and 2011, and in August 2011. Diatoms in samples were categorized into 98 taxa. The diatom flux maxima were characterized by many resting spores in November–December and by the sea-ice-associated diatom Fossula arctica in August 2011. These assemblages along with abundant clay minerals in the samples suggest a significant influence of shelf-origin materials transported by mesoscale eddies, which developed along the Chukchi Sea shelf break. In contrast, the fluxes of total mass and diatoms were reduced in summer 2012. We hypothesize that this suppression reflects the influx of oligotrophic water originating from the central Canada Basin. A physical oceanographic model demonstrated that oligotrophic surface water from the Beaufort Gyre was supplied to Station NAP from December 2011 to the early half of 2012.

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