Preprints
https://doi.org/10.5194/egusphere-2023-2106
https://doi.org/10.5194/egusphere-2023-2106
04 Oct 2023
 | 04 Oct 2023

Fjord circulation induced by melting icebergs

Kenneth G. Hughes

Abstract. In an iceberg-choked fjord, meltwater can drive circulation. Down-fjord of the ice, buoyancy and rotation lead to an outflowing surface coastal current hugging one side of the fjord with an inflowing counter current below. To predict the structure and evolution of these currents, we develop an analytical model – complemented by numerical simulations – that involve a rectangular fjord initially at rest. Specifically, we (i) start with the so-called Rossby adjustment problem, (ii) reconfigure it for a closed channel with stratification, and (iii) generalize the conventional 'dam-break' scenario to a gradual-release one that mimics the continual, slow injection of meltwater. Implicit in this description is the result that circulation is mediated by internal Kelvin waves. The analytical model shows that if the total meltwater flux increases (e.g., a larger melange, warmer water, or enhanced ice–ocean turbulence), then circulation strength increases as would be expected. For realistic parameters, a given meltwater flux induces an exchange flow that is ~50 times larger. This factor decreases with increasing water column stratification and vice versa.

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Journal article(s) based on this preprint

21 Mar 2024
Fjord circulation induced by melting icebergs
Kenneth G. Hughes
The Cryosphere, 18, 1315–1332, https://doi.org/10.5194/tc-18-1315-2024,https://doi.org/10.5194/tc-18-1315-2024, 2024
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

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A mathematical and conceptual model of how the melting of hundreds of icebergs generates...
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