Sea ice salinity and structure: A winter time series of sali

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TitleSea ice salinity and structure: A winter time series of salinity and its distributionAbstractWe present a winter time series of Antarctic sea ice salinity from eastern McMurdo Sound, an area close to an ice shelf where a subice platelet layer forms below the sea ice late in winter. This dramatically changes the sea ice structure as the sea ice grows into the subice platelet layer. Every 2weeks during the 5months of sea ice formation, salinity profiles were measured, along with detailed measurements of ice structure and growth rates. Once the influence of growth rate on sea ice bulk salinity is removed, the data from 69 cores and the results of a basic parameterization demonstrate that bulk salinity for platelet ice is higher than that for columnar sea ice. We also present measurements of the salinity profile close to the ice-water interface and use these to investigate the expected regime of fluid flow within the permeable portions of the sea ice, with particular reference to mushy layer and percolation theory. Finally, we provide a new distribution of sea ice salinity from 740 measurements, which can be interpreted as the sum of two spatial fields that we attribute to sea ice samples with and without brine channels and which should be reproduced by any realistic sea ice models. This distribution suggests that two measurements of quantities linearly linked to sea ice salinity must differ by 29% if they are to be considered different with 90% confidence. Copyright 2012 by the American Geophysical Union.AcknowledgementsThis work, part of New Zealand's contribution to the IPY, was funded by the Foundation for Research Science and Technology and a University of Otago postgraduate scholarship. Antarctica New Zealand provided logistical support. We thank Brian Staite and the 2009 Scott Base wintering team for valuable assistance in the field. We are grateful to Craig Purdie for advice while planning this experiment and Inga Smith and Chris Petrich for comments that improved this paper. Some temperature data were provided by Joe Trodahl. The comments of two anonymous reviewers significantly improved this paper.

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1st AuthorGough, A.AuthorGough, A.Mahoney, A.Langhorne, P.Williams, M.Haskell, T.Year2012JournalJournal of Geophysical Research: OceansVolume117Number3DOI10.1029/2011JC007527URLhttps://www.scopus.com/inward/recor.....acf552e967d247edb85f8eab5KeywordsPlateletsSalinity measurementTime series, Antarctic sea iceIce samplesIce shelvesIce structuresIce-water interfacesPercolation theorySea ice formationsSea ice modelsSea ice salinitySpatial fieldsWinter time, Sea ice, fluid flowice shelfparameterizationpercolationsalinitysea icetime serieswinter, AntarcticaEast AntarcticaMcMurdo Sound, rank5ProgrammeK131 - Sea Ice and Southern Ocean Processes

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TypeArticleCitationGough, A., Mahoney, A., Langhorne, P., Williams, M. and Haskell, T. (2012). Sea ice salinity and structure: A winter time series of salinity and its distribution. Journal of Geophysical Research: Oceans, 117(3)