Tidal ice dynamics in the area of Svalbard and Frans Josef Land

[1] A one-layer reduced-gravity model is used to investigate the wave-induced mass flux in internal Kelvin waves along a straight coast beneath shore-fast ice. The waves are generated by barotropic tidal pumping at narrow sounds, and the ice lid introduces a no-slip condition for the horizontal wave motion. The mean Lagrangian fluxes to second order in wave steepness are obtained by integrating the equations of momentum and mass between the material interface and the surface. The mean flow is forced by the conventional radiation stress for internal wave motion, the mean pressure gradient due to the sloping surface, and the frictional drag at the boundaries. The equations that govern the mean fluxes are expressed in terms of mean Eulerian variables, while the wave forcing terms are given by the horizontal divergence of the Stokes flux. Analytical results show that the effect of friction induces a mean Eulerian flux along the coast that is comparable to the Stokes flux. In addition, the horizontal divergence of the total mean flux along the coast induces a small mass flux in the cross-shore direction. This flux changes the mean thickness of the upper layer outside the trapping region and may facilitate geostrophically balanced boundary currents in enclosed basins. This is indeed demonstrated by numerical solutions of the flux equations for confined areas larger than the trapping region. Application of the theory to Arctic waters is discussed, with emphasis on the transport of biological material and pollutants in nearshore regions.Citation: Støylen, E., and J. E. H. Weber (2010), Mass transport induced by internal Kelvin waves beneath shore-fast ice,

Section: Nonlinear Analysis For a Straight Wallmentioning

confidence: 99%

Mass transport induced by internal Kelvin waves beneath shore‐fast ice

Støylen

Weber

2010

“…Satellite image of ice cover in the vicinity of Spitsbergen on June 1, 1988, from Dmitriev et al [1991] with permission from Polar Research. Elliptically shaped leads are formed behind grounded icebergs as sea ice is driven by tidal currents.…”

Section: Introductionmentioning

confidence: 99%

Role of tides in Arctic ocean/ice climate

Holloway

Proshutinsky

2007

[1] A three-dimensional coupled ocean/ice model, intended for long-term Arctic climate studies, is extended to include tidal effects. From saved output of an Arctic tides model, we introduce parameterizations for (1) enhanced ocean mixing associated with tides and (2) the role of tides fracturing and mobilizing sea ice. Results show tides enhancing loss of heat from Atlantic waters. The impact of tides on sea ice is more subtle as thinning due to enhanced ocean heat flux competes with net ice growth during rapid openings and closings of tidal leads. Present model results are compared with an ensemble of nine models under the Arctic Ocean Model Intercomparison Project (AOMIP). Among results from AOMIP is a tendency for models to accumulate excessive Arctic Ocean heat throughout the intercomparison period 1950 to 2000 which is contrary to observations. Tidally induced ventilation of ocean heat reduces this discrepancy.

“…The structure of these waves emerges with refining of the numerical lattice used for computation. In the charts calculated with spatial grid of about 50 km[Gjevik, 1990;Proshutinsky, 1991] the dynamics of the K1 wave was governed by two amphidromic points close to Bear Island and one degenerated amphidromic point on the southern coa.st of Spitsbergen. Two slight maxima of sea level, one near the Norwegian coast and the second south of Sva.…”

mentioning

confidence: 99%

Topographic enhancement of tidal motion in the western Barents Sea

Kowalik¹,

Proshutinsky²

1995

Self Cite

Abate-notA hi•h-roe•l,,fi•n n,,mori,-nl l•**ice is used to study a topographically trapped motion around islands and shallow banks of the western Barents Sea caused both by the semidiurnal and diurnal tidal waves. Observations and model computations in the vicinity of Bear Island show well-developed trapped motion with distinctive tidal oscillatory motion. Numerical investigations demonstrate that one source of the trapped motion is tidal current rectification over shallow topography. Tidal motion supports residual currents of the order of 8 cm s -1 around Bear Island and shallow Spitsbergenbanken. The structures of enhanced tidal currents for the semidiurnal components are generated in the shallow areas due to topographic amplification. In the diurnal band of oscillations the maximum current is associated with the shelf wave occurrence. Residual currents due to diurnal tides occur at both the shallow areas and the shelf slope in regions of maximum topographic gradients. Surface manifestation of the diurnal current enhancement is the local maximum of tidal amplitude at the shelf break of the order of 5 to 10 cm. Tidal current enhancement and tidally generated residual currents in the Bear Island and Spitsbergenbanken regions cause an increased generation of ice leads, ridges and, trapped motion of the ice floes. OscillaLory and residual Lidal currenLs in Lhe BI area are imporLant because •his island is located close to •he deep Norwegian Sea. Heal and salL, enLering into •he shallow waLer around Lhe BI and shallow banks, are modified Lhrough Lhe tidal motion. Residual tidal motion calculated from an 18-km grid model for •he shallow areas souLh of Spitsbergen depicts small velocity of the order of 1 cm s -• [IIarm•, 19912]. It exactly delinea.•es polar fron• location and •herefore can influ-,,' ß ß ß , , ß 100---"" o, KOWALIK AND PROSHUTINSKY: ENHANCEMENT OF TIDAL MOTION culations demonstrate that in the vicinity of BI the polar front can be generated and maintained not only by the inflow of the warm Atlantic waters and outflow of the cold Arctic waters, but also by the tidal motion. Shelf Res., 10, 81-86, 1990. Pca.se, C. H., P. Turet, R. S. Pritchard, and J. E. Overland, Barents Sea tidal, wind drift, and inertial motion from ARGOS ice buoys during CEAREX, J. Geophys. Res., in press, 1995. Pingtee, R. D., and L. Maddock, Rotary currents and residual circulation around banks and islands, Deep Sea Res., Part A, 32, 929-947, 1985. Pingtee, R. D., P.M. Holligan, and G. T. Mardell, The effect of vertical stability on phytoplankton distributions in the summer on the northwest European shelf, Deep Sea Res., Part A, 25, 1011-1028, 1978. Proshutinsky, A. Yu., Tidal water and ice dynamics in the rents in the western Dutch Wadden Sea, in Coastal and Estuarine Studies, edited by R. T. Cheng, pp. 93-104, Springer-Verlag, New York, 1990. Robinson, I.S., Tidal vorticity and residual circulation, Deep Sea Res., part A, 28, 195-212, 1981. Sandven, S., and O. M. Johannessen, The use of microwave remote sensing for sea ice studies...