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TitleNon-linear thermal transport and brine convection in first-year sea ice
Publication TypeJournal Article
Year of Publication1998
AuthorsMcguinness, M.J., Trodahl H.J., Collins K., and Haskell T.G.
JournalAnnals of Glaciology
Pagination471 - 476
Date Published1998
ISSN02603055 (ISSN)
Keywordsbrine, climate modeling, Sea ice, thermal convection
AbstractWe report the first results from a programme recently set up to directly measure the thermal conductivity of young sea ice. An array of thermistors frozen into first-year Antarctic sea ice provides temperature vs depth data, which is fitted directly with a partial differential equation for heat conduction. Temperatures are recorded every hour at 20 vertical intervals of 100 mm over a period of 5 months, allowing accurate and direct estimation of the thermal conductivity. Preliminary results indicate that the thermal conductivity is in the expected range, with some evidence of non-linear effects deeper in the ice. A larger variance in data is evident at higher temperature gradients and at greater depths in the ice. Preliminary modelling of the impact of brine migration on heat transport through first-year sea ice is presented. Diffusion-driven brine pocket migration is too slow to contribute significantly to heat flow, but the convective instability of inclined brine slots or tubes is a promising mechanism.

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