Small-scale physical processes in the Arctic Ocean

Author(s):  
Laurie Padman
2021 ◽  
Author(s):  
Magda Carr ◽  
Peter Sutherland ◽  
Andrea Haase ◽  
Karl-Ulrich Evers ◽  
Ilker Fer ◽  
...  

<p>Oceanic internal waves (IWs) propagate along density interfaces and are ubiquitous in stratified water. Their properties are influenced strongly by the nature and form of the upper and lower bounding surfaces of the containing basin(s) in which they propagate.<span>  </span>As the Arctic Ocean evolves to a seasonally more ice-free state, the IW field will be affected by the change. The relationship between IW dynamics and ice is important in understanding (i) the general circulation and thermodynamics in the Arctic Ocean and (ii) local mixing processes that supply heat and nutrients from depth into upper layers, especially the photic zone. This, in turn, has important ramifications for sea ice formation processes and the state of local and regional ecosystems.<span>  </span>Despite this, the effect of diminishing sea ice cover on the IW field (and vice versa) is not well established. A better understanding of IW dynamics in the Arctic Ocean and, in particular, how the IW field is affected by changes in both ice cover and stratification, is central in understanding how the rapidly changing Arctic will adapt to climate change.</p><p> </p><p>An experimental study of internal solitary waves (ISWs) propagating in a stably stratified two-layer fluid in which the upper boundary condition changes from open water to ice are studied for grease, level, and nilas ice. The experiments show that the internal wave-induced flow at the surface is capable of transporting sea-ice in the horizontal direction. In the level ice case, the transport speed of, relatively long ice floes, nondimensionalized by the wave speed is linearly dependent on the length of the ice floe nondimensionalized by the wave length. It will also be shown that bottom roughness associated with different ice types can cause varying degrees of vorticity and small-scale turbulence in the wave-induced boundary layer beneath the ice. Measures of turbulent kinetic energy dissipation under the ice are shown to be comparable to those at the wave density interface. Moreover, in cases where the ice floe protrudes into the pycnocline, interaction with the ice edge can cause the ISW to break or even be destroyed by the process. The results suggest that interaction between ISWs and sea ice may be an important mechanism for dissipation of ISW energy in the Arctic Ocean.</p><p> </p><p><strong>Acknowledgements</strong></p><p>This work was funded through the EU Horizon 2020 Research and Innovation Programme Hydralab+.</p>


2001 ◽  
Vol 33 ◽  
pp. 567-576 ◽  
Author(s):  
Ye. Aksenov ◽  
A.C. Coward

AbstractTo investigate the Arctic Ocean Circulation, results from a high-resolution fully global ocean model have been analyzed. The results come from two runs of the Ocean Circulation and Climate Advanced Modelling project (OCCAM) model, developed and run by the Southampton Oceanography Centre, at 1/4° × 1/4° and 1/8° × 1/8° resolution. The model is based on the Bryan-Semtner-Cox model and has 36 vertical levels. Enhancements include a free surface, an improved advection scheme and an improved treatment of the surface fresh-water flux. The model is forced with a monthly European Centre for Medium-range Weather Forecasts wind-stress climatology. It reproduces many of the fine-scale features found in the Arctic Ocean. The analysis concentrates on several of the key features, including the highly energetic eddy system in the western part of the Beaufort Sea, East Greenland West and Spitsbergen Currents and the detailed structure of the marginal currents along the Siberian and Canadian coasts. Much of the paper is focused on the water transport through the Bering and Fram Straits and through the Canadian Archipelago. Comparisons of the model net fluxes through the straits against observations are presented. The analyses of the results demonstrate the ability of the fine-resolution model to simulate features such as small-scale eddies and jets, which have some agreement with the limited observations available.


2016 ◽  
Vol 70 (1) ◽  
pp. 19-27
Author(s):  
M Ogi ◽  
S Rysgaard ◽  
DG Barber ◽  
T Nakamura ◽  
B Taguchi

Data Series ◽  
10.3133/ds862 ◽  
2014 ◽  
Author(s):  
Lisa L. Robbins ◽  
Jonathan Wynn ◽  
Paul O. Knorr ◽  
Bogdan Onac ◽  
John T. Lisle ◽  
...  

2020 ◽  
Vol 29 (1) ◽  
pp. 138-154
Author(s):  
R.V. Smirnov ◽  
O.V. Zaitseva ◽  
A.A. Vedenin

A new species of Pogonophora obtained from one station at a depth of 25 m from near the Dikson Island in the Kara Sea is described. Galathealinum karaense sp. nov. is one of the largest pogonophorans, the first known representative of the rare genus Galathealinum Kirkegaard, 1956 in the Eurasian part of the Arctic Ocean and a highly unusual finding for the desalted shallow of the Yenisey Gulf. Several characters occurring in the new species are rare or unique among the congeners: under-developed, hardly discernible frills on the tube segments, extremely thin felted fibres in the external layer of the tube, and very faintly separated papillae in the anterior part of the trunk. Morphological characters useful in distinguishing species within the genus Galathealinum are defined and summarised in a table. Diagnosis of the genus Galathealinum is emended and supplemented by new characters. Additionally, three taxonomic keys are provided to the species of Galathealinum and to the known species of the Arctic pogonophorans using either animals or their empty tubes only, with the brief zoogeographical information on each Arctic species.


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