Steady Models of Arctic Shelf-Basin Exchange
Steady-state exchanges between the Arctic shelves and the central basins are estimated using an inverse box model. The model accounts for data uncertainty in the estimates, and quantifies the solution uncertainty. Aggregate estimates of fluxes across the Arctic boundary, with their uncertainties, ar...
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Format: | Text |
Language: | English |
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1998
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Online Access: | http://www.dtic.mil/docs/citations/ADA363518 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA363518 |
Summary: | Steady-state exchanges between the Arctic shelves and the central basins are estimated using an inverse box model. The model accounts for data uncertainty in the estimates, and quantifies the solution uncertainty. Aggregate estimates of fluxes across the Arctic boundary, with their uncertainties, are generated from flux estimates published between 1975 and 1997. From the aggregate estimates, mass-, heat-, and salt-conserving boundary flux estimates are derived, which imply a net flux of water from the shelves to the basins of 1.2 +/- 0.4 Sv. Due primarily to boundary flux data uncertainty, constraints of mass, heat, and salt conservation alone cannot determine how much shelf-basin exchange occurs via dense overflows, and how much via the surface mixed layer. Adding delta 18O constraints, however, greatly reduces the uncertainty. Dense water flux from the shelves to the basins is necessary for maintaining steady state, but shelfbreak upwelling is not required. Proper representation of external sources feeding the shelves, rather than the basins, is important to obtain the full range of plausible steady solutions. Implications for the study of Arctic change are discussed. |
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