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We have developed a two-dimensional coupled glacier–fjord model, which runs automatically using Elmer/Ice and MITgcm software packages, to investigate the magnitude of submarine melting along a vertical glacier front and its potential influence on glacier calving and front position changes. We apply this model to simulate the Hansbreen glacier–Hansbukta proglacial–fjord system, Southwestern Svalbard, during the summer of 2010. The limited size of this system allows us to resolve some of the small-scale processes occurring at the ice–ocean interface in the fjord model, using a 0.5 s time step and a 1 m grid resolution near the glacier front. We use a rich set of field data spanning the period April–August 2010 to constrain, calibrate and validate the model. We adjust circulation patterns in the fjord by tuning subglacial discharge inputs that best match observed temperature while maintaining a compromise with observed salinity, suggesting a convectively driven circulation in Hansbukta. The results of our model simulations suggest that both submarine melting and crevasse hydrofracturing exert important controls on seasonal frontal ablation, with submarine melting alone not being sufficient for reproducing the observed patterns of seasonal retreat. Both submarine melt and calving rates accumulated along the entire simulation period are of the same order of magnitude, ~100 m. The model results also indicate that changes in submarine melting lag meltwater production by 4–5 weeks, which suggests that it may take up to a month for meltwater to traverse the englacial and subglacial drainage network. [ABSTRACT FROM AUTHOR]

Abstract: We have developed and run a model with sufficiently high resolution (∼9km and 45 levels) and a large enough spatial domain to allow for realistic representation of flow through the narrow and shallow straits in the northern Bering Sea. This is potentially important for quantification of long-term mean and time-dependent ocean circulation, and water mass and property exchanges between the Pacific and Arctic Oceans. Over a 23 year interval (1979–2001), mean transport through Bering Strait is estimated to be 0.65Sv. Comparison of our model results with published observations indicates that ocean circulation is not only variable at seasonal to interdecadal scales but it is also responsive to short-term atmospheric forcing. One of such events occurred during the winter of 2000–2001 with reversed oceanic flow in some areas and much reduced sea-ice cover. Analyses of eddy kinetic energy fields identify some high biological productivity regions of the Chirikov Basin coincident with persistent high energy (up to 2700cm2 s−2 in the surface layer and up to 2600cm2 s−2 at mid-depth) throughout the annual cycle. Model output in the Bering Strait region is validated against several time series of moored observations of water mass properties. Comparison with shipboard observations of near-bottom salinity from late winter through autumn indicates that the model reasonably represents the major water-mass properties in the region. The modeled vertical water-column structure in the northern Bering Sea allows increased understanding of the mechanisms of water transformation and transport northward through Bering Strait into the Chukchi and Beaufort Seas. We conclude that the long-term model results for the northern Bering Sea provide important insights into the ocean circulation and fluxes and they are a useful frame of reference for limited observations that are short-term and/or cover only a small geographic region. [Copyright &y& Elsevier]