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The University of Southampton
Ocean and Earth Science, National Oceanography Centre Southampton

Research project: Processes Regulating Iron Supply at the Mesoscale in the Ross Sea (PRISM-RS)

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The Ross Sea continental shelf is the single most productive area in the Southern Ocean, and may comprise a significant but unaccounted for oceanic CO2 sink, largely driven by phytoplankton production. However, the processes that control the magnitude of primary production in this region are not well understood.

Smith, W.O. Jr, P.N. Sedwick, K.R. Arrigo, D.G. Ainley, and A.H. Orsi (2012). The Ross Sea in a sea of change. Oceanography 25(3)90-130
Smith et al. (2012)

During summer, an observed abundance of macronutrients and scarcity of dissolved iron are consistent with iron limitation of phytoplankton growth in the Ross Sea polynya, as is further suggested by shipboard bioassay experiments. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross sea: circumpolar deep water intruding from the shelf edge; sediments on shallow banks and nearshore areas; melting sea ice around the perimeter of the polynya; and glacial meltwater from the Ross Ice Shelf. These potential iron sources are isolated, either laterally or vertically, from the surface waters of the Ross Sea for much of the growing season.

McGillicuddy, D.J., Hofmann, E.E., Smith, W.O., Greenan, B., and T.S. Bibby, 2012. PRISM-RS: Processes Regulating Iron Supply at the Mesoscale in the Ross Sea (PRISM-RS). IMBER Newsletter Issue n°20-May 2012.

PRISM-RS is supported by the United States Antarctic Program of the National Science Foundation. Grant awarded to: Dennis J. McGillicuddy, Jr., Woods Hole Oceanographic Institution, Woods Hole, MA, USA; Eileen Hofmann, Mike Dinniman, John Klinck, Peter Sedwick, Old Dominion University, Norfolk, VA, USA; Walker Smith, Virginia Institute of Marine Science, Gloucester Point, VA, USA; Blair Greenan, Bedford Institute of Oceanography, Dartmouth NS, Canada.


We hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. Our cruise plan was designed to accomplish two distinct objectives: (A) regional-scale, high-resolution transects to characterize the hypothesized source regions of iron, and (B) mini-process studies to examine selected mesoscale features in detail.

Key Contacts

Dr Tom Bibby

PhDs and Other Opportunities


Related research groups

Marine Biogeochemistry
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