Distributions, sources, and transformations of dissolved and particulate iron on the Ross Sea continental shelf during summer
Marsay, Christopher M.
Barrett, Pamela M.
McGillicuddy, Dennis J.
Sedwick, Peter N.
MetadataShow full item record
We report water column dissolved iron (dFe) and particulate iron (pFe) concentrations from 50 stations sampled across the Ross Sea during austral summer (January–February) of 2012. Concentrations of dFe and pFe were measured in each of the major Ross Sea water masses, including the Ice Shelf Water and off-shelf Circumpolar Deep Water. Despite significant lateral variations in hydrography, macronutrient depletion, and primary productivity across several different regions on the continental shelf, dFe concentrations were consistently low (<0.1 nM) in surface waters, with only a handful of stations showing elevated concentrations (0.20–0.45 nM) in areas of melting sea ice and near the Franklin Island platform. Across the study region, pFe associated with suspended biogenic material approximately doubled the inventory of bioavailable iron in surface waters. Our data reveal that the majority of the summertime iron inventory in the Ross Sea resides in dense shelf waters, with highest concentrations within 50 m of the seafloor. Higher dFe concentrations near the seafloor are accompanied by an increased contribution to pFe from authigenic and/or scavenged iron. Particulate manganese is also influenced by sediment resuspension near the seafloor but, unlike pFe, is increasingly associated with authigenic material higher in the water column. Together, these results suggest that following depletion of the dFe derived from wintertime convective mixing and sea ice melt, recycling of pFe in the upper water column plays an important role in sustaining the summertime phytoplankton bloom in the Ross Sea polynya.
Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 6371–6393, doi:10.1002/2017JC013068.
Suggested CitationArticle: Marsay, Christopher M., Barrett, Pamela M., McGillicuddy, Dennis J., Sedwick, Peter N., "Distributions, sources, and transformations of dissolved and particulate iron on the Ross Sea continental shelf during summer", Journal of Geophysical Research: Oceans 122 (2017): 6371–6393, DOI:10.1002/2017JC013068, https://hdl.handle.net/1912/9314
Showing items related by title, author, creator and subject.
Fewings, Melanie R.; Lentz, Steven J.; Fredericks, Janet J. (American Meteorological Society, 2008-11)Six-yr-long time series of winds, waves, and water velocity from a cabled coastal observatory in 12 m of water reveal the separate dependence of the cross-shelf velocity profile on cross-shelf and along-shelf winds, waves, ...
The effect of stratification on wind-driven, cross-shelf circulation and transport on the inner continental shelf Horwitz, Rachel M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-06)Observations from a three-year field program on the inner shelf south of Martha's Vineyard, MA and a numerical model are used to describe the effect of stratification on inner shelf circulation, transport, and sediment ...
Cross-shelf circulation and momentum and heat balances over the inner continental shelf near Martha's Vineyard, Massachusetts Fewings, Melanie R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)The water circulation and evolution of water temperature over the inner continental shelf are investigated using observations of water velocity, temperature, density, and bottom pressure; surface gravity waves; wind ...