The seasonal appearance of ice shelf water in coastal Antarc
Details of Research
TitleThe seasonal appearance of ice shelf water in coastal Antarctica and its effect on sea ice growthAbstractIn this paper we report measurements from the first year-round mooring underneath sea ice in McMurdo Sound, Antarctica, which we combine with full-depth ocean profiles to identify the incremental appearance of potentially supercooled ice shelf water (ISW). We investigate the effects of ISW on sea ice using observations of sea ice growth and crystal structure together with under-ice photography. We show that the appearance of ISW at the surface leads to a disruption in the columnar texture of the sea ice, but that persistent growth enhancement occurs only once the entire water column has cooled to the surface freezing point. In doing so, we demonstrate the possibility of inferring the presence of ISW beneath sea ice through crystallographic analysis of cores. These findings will be useful for both modeling and observing the extent of ISW-enhanced ice growth. In addition, we found that the local growth of first-year landfast sea ice only accounted for half of the observed increase in salinity over the water column, which indicates that polynyas are responsible for approximately half of the salt flux into McMurdo Sound. Copyright 2011 by the American Geophysical Union.AcknowledgementsThis study was supported by a grant fromthe New Zealand Foundation for Research, Science and Technology andcomprised part of New Zealand'sontribution to the International PolarYear. We are grateful for support from Antarctica New Zealand and the entire 2009 Scott Base winter team, in particular, Brian Staite for outstanding field support. This study was also made poss ible by a postgraduateresearch scholarship from the University of Otago and support from the National Institute for Water and Atmospheric Research and Industrial Research Limited. We also wish to acknowledge Wolfgang Rack, Russell Frew, and Craig Stewart for providing data, analyzing samples, and preparing instrumentation. Greg Leonard, Craig Purdie, Inga Smith, and Eddy Carmack also contributed valuable discussions. We also wish to thank the two anonymous reviewers for their thorough reviews and insightful comments.
1st AuthorMahoney, A.AuthorMahoney, A.Gough, A.Langhorne, P.Robinson, N.Stevens, C.Williams, M.Haskell, T.Year2011JournalJournal of Geophysical Research: OceansVolume116Number11DOI10.1029/2011JC007060URLhttps://www.scopus.com/inward/recor.....d0afe1404a767beb3a093e6beKeywordsCrystal structure, AntarcticaCrystallographic analysisFirst-yearGrowth enhancementIce growthIce shelf watersLand-fastOcean profilesSalt fluxSea ice growthSurface freezingWater columns, Sea ice, coastal zonecrystal structurecrystallographyfreezingice shelfmooring systemphotographypolynyasalinitysea iceseasonalitysupercoolingwater column, AntarcticaEast AntarcticaMcMurdo Sound, rank5ProgrammeK131 - Sea Ice and Southern Ocean Processes
TypeArticleCitationMahoney, A., Gough, A., Langhorne, P., Robinson, N., Stevens, C., Williams, M. and Haskell, T. (2011). The seasonal appearance of ice shelf water in coastal Antarctica and its effect on sea ice growth. Journal of Geophysical Research: Oceans, 116(11)
Antarctica NZ (26th Nov 2018). The seasonal appearance of ice shelf water in coastal Antarc . In Website Antarctica NZ. Retrieved 29th Sep 2020 06:31, from https://adam.antarcticanz.govt.nz/nodes/view/63638