scholarly journals The Yermak Plateau in the Arctic Ocean in the light of reflection seismic data-implication for its tectonic and sedimentary evolution

2011 ◽  
Vol 187 (3) ◽  
pp. 1334-1362 ◽  
Author(s):  
W. H. Geissler ◽  
W. Jokat ◽  
H. Brekke
Keyword(s):  
Arctic Ocean ◽  
Seismic Data ◽  
The Arctic ◽  
Reflection Seismic ◽  
Sedimentary Evolution ◽  
The Arctic Ocean ◽  
Yermak Plateau

Correlations between the Lomonosov Ridge, Marvin Spur and adjacent basins of the Arctic Ocean based on seismic data

2009 ◽  
Vol 472 (1-4) ◽  
pp. 309-322 ◽  
Author(s):  
A.E. Langinen ◽  
N.N. Lebedeva-Ivanova ◽  
D.G. Gee ◽  
Yu.Ya. Zamansky
Keyword(s):  
Arctic Ocean ◽  
Seismic Data ◽  
The Arctic ◽  
Lomonosov Ridge ◽  
The Arctic Ocean

Nonlinear internal wave generation over the Yermak Plateau 

2021 ◽  
Author(s):  
Gabin Urbancic ◽  
Kevin Lamb ◽  
Ilker Fer ◽  
Laurie Padman
Keyword(s):  
Internal Wave ◽  
Arctic Ocean ◽  
Internal Waves ◽  
Wave Generation ◽  
The Arctic ◽  
Nonlinear Internal Wave ◽  
Nonlinear Internal Waves ◽  
The Arctic Ocean ◽  
Yermak Plateau ◽  
Internal Wave Generation

<p>North of the critical latitude (78.4), internal waves of the M<sub>2</sub> tidal frequency can no longer freely propagate, and the energy conversion from the barotropic to the internal tides vanishes. Near the continental slopes around the Arctic Ocean, internal wave energy is enhanced and comparable to values at mid-latitudes (Rippeth et al. 2015, Levine et al. 1985). Observations on the northern flank of the Yermak Plateau (YP) has characterized the region as one of enhanced internal wave activity and nonlinear internal waves have been observed (Czipott et al. 1991, Padman and Dillon 1991).</p><p>The YP is a bathymetry feature stretching out into the Fram Strait north-west of Svalbard. The YP plays a prominent role in the Arctic’s heat balance due to its interaction with the West-Spitsbergen current which is a main contributor to the heat transport into the Arctic Ocean. Nonlinear waves generated over the YP are a significant energy source for mixing and can therefore modulate and force exchange processes.</p><p>To study the nonlinear internal wave generation mechanisms over the YP, we used a high resolution, nonlinear, non-hydrostatic model. We found that nonlinear internal waves are forced not by the M<sub>2</sub> but the K<sub>1</sub> tide which has been observed to have significant variability over the YP (Padman et al. 1992). Barotropic, diurnal shelf waves generated on the eastern side of the YP propagates counter-clockwise, amplifying the cross-slope currents. This amplification is the necessary condition for nonlinear internal wave generation over the YP.</p>

scholarly journals Tidal forcing, energetics, and mixing near the Yermak Plateau

Ocean Science ◽  
2015 ◽  
Vol 11 (2) ◽  
pp. 287-304 ◽  
Author(s):  
I. Fer ◽  
M. Müller ◽  
A. K. Peterson
Keyword(s):  
Energy Conversion ◽  
Arctic Ocean ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
Topographic Feature ◽  
Dissipation Rates ◽  
Conversion Rates ◽  
The Arctic Ocean ◽  
Yermak Plateau

Abstract. The Yermak Plateau (YP), located northwest of Svalbard in Fram Strait, is the final passage for the inflow of warm Atlantic Water into the Arctic Ocean. The region is characterized by the largest barotropic tidal velocities in the Arctic Ocean. Internal response to the tidal flow over this topographic feature locally contributes to mixing that removes heat from the Atlantic Water. Here, we investigate the tidal forcing, barotropic-to-baroclinic energy conversion rates, and dissipation rates in the region using observations of oceanic currents, hydrography, and microstructure collected on the southern flanks of the plateau in summer 2007, together with results from a global high-resolution ocean circulation and tide model simulation. The energetics (depth-integrated conversion rates, baroclinic energy fluxes and dissipation rates) show large spatial variability over the plateau and are dominated by the luni-solar diurnal (K1) and the principal lunar semidiurnal (M2) constituents. The volume-integrated conversion rate over the region enclosing the topographic feature is approximately 1 GW and accounts for about 50% of the M2 and approximately all of the K1 conversion in a larger domain covering the entire Fram Strait extended to the North Pole. Despite the substantial energy conversion, internal tides are trapped along the topography, implying large local dissipation rates. An approximate local conversion–dissipation balance is found over shallows and also in the deep part of the sloping flanks. The baroclinic energy radiated away from the upper slope is dissipated over the deeper isobaths. From the microstructure observations, we inferred lower and upper bounds on the total dissipation rate of about 0.5 and 1.1 GW, respectively, where about 0.4–0.6 GW can be attributed to the contribution of hot spots of energetic turbulence. The domain-integrated dissipation from the model is close to the upper bound of the observed dissipation, and implies that almost the entire dissipation in the region can be attributed to the dissipation of baroclinic tidal energy.

scholarly journals Water mass distribution in Fram Strait and over the Yermak Plateau in summer 1997

2000 ◽  
Vol 18 (6) ◽  
pp. 687-705 ◽  
Author(s):  
B. Rudels ◽  
R. Meyer ◽  
E. Fahrbach ◽  
V. V. Ivanov ◽  
S. Østerhus ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Mass ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
The West ◽  
The Arctic Ocean ◽  
Yermak Plateau ◽  
Eurasian Basin ◽  
West Spitsbergen

Abstract. The water mass distribution in northern Fram Strait and over the Yermak Plateau in summer 1997 is described using CTD data from two cruises in the area. The West Spitsbergen Current was found to split, one part recirculated towards the west, while the other part, on entering the Arctic Ocean separated into two branches. The main inflow of Atlantic Water followed the Svalbard continental slope eastward, while a second, narrower, branch stayed west and north of the Yermak Plateau. The water column above the southeastern flank of the Yermak Plateau was distinctly colder and less saline than the two inflow branches. Immediately west of the outer inflow branch comparatively high temperatures in the Atlantic Layer suggested that a part of the extraordinarily warm Atlantic Water, observed in the boundary current in the Eurasian Basin in the early 1990s, was now returning, within the Eurasian Basin, toward Fram Strait. The upper layer west of the Yermak Plateau was cold, deep and comparably saline, similar to what has recently been observed in the interior Eurasian Basin. Closer to the Greenland continental slope the salinity of the upper layer became much lower, and the temperature maximum of the Atlantic Layer was occasionally below  0.5 °C, indicating water masses mainly derived from the Canadian Basin. This implies that the warm pulse of Atlantic Water had not yet made a complete circuit around the Arctic Ocean. The Atlantic Water of the West Spitsbergen Current recirculating within the strait did not extend as far towards Greenland as in the 1980s, leaving a broader passage for waters from the Atlantic and intermediate layers, exiting the Arctic Ocean. A possible interpretation is that the circulation pattern alternates between a strong recirculation of the West Spitsbergen Current in the strait, and a larger exchange of Atlantic Water between the Nordic Seas and the inner parts of the Arctic Ocean.Key words: Oceanography: general (Arctic and Antarctic oceanography; water masses) - Oceanography: physical (general circulation)

Internal Waves and Mixing in the Marginal Ice Zone near the Yermak Plateau*

2010 ◽  
Vol 40 (7) ◽  
pp. 1613-1630 ◽  
Author(s):  
Ilker Fer ◽  
Ragnheid Skogseth ◽  
Florian Geyer
Keyword(s):  
Internal Wave ◽  
Arctic Ocean ◽  
Internal Waves ◽  
Noise Level ◽  
Atlantic Water ◽  
The Arctic ◽  
Cold Side ◽  
Marginal Ice Zone ◽  
The Arctic Ocean ◽  
Yermak Plateau

Abstract Observations were made of oceanic currents, hydrography, and microstructure in the southern Yermak Plateau in summer 2007. The location is in the marginal ice zone at the Arctic Front northwest of Svalbard, where the West Spitsbergen Current (WSC) carries the warm Atlantic Water into the Arctic Ocean. Time series of approximately 1-day duration from five stations (upper 520 m) and of an 8-day duration from a mooring are analyzed to describe the characteristics of internal waves and turbulent mixing. The spectral composition of the internal-wave field over the southern Yermak Plateau is 0.1–0.3 times the midlatitude levels and compares with the most energetic levels in the central Arctic. Dissipation rate and eddy diffusivity below the pycnocline increase from the noise level on the cold side of the front by one order of magnitude on the warm side, where 100-m-thick layers with average diffusivities of 5 × 10−5 m2 s−1 lead to heat loss from the Atlantic Water of 2–4 W m−2. Dissipation in the upper 150 m is well above the noise level at all stations, but strong stratification at the cold side of the front prohibits mixing across the pycnocline. Close to the shelf, at the core of the Svalbard branch of the WSC, diffusivity increases by another factor of 3–6. Here, near-bottom mixing removes 15 W m−2 of heat from the Atlantic layer. Internal-wave activity and mixing show variability related to topography and hydrography; thus, the path of the WSC will affect the cooling and freshening of the Atlantic inflow. When generalized to the Arctic Ocean, diapycnal mixing away from abyssal plains can be significant for the heat budget. Around the Yermak Plateau, it is of sufficient magnitude to influence heat anomaly pulses entering the Arctic Ocean; however, diapycnal mixing alone is unlikely to be significant for regional cooling of the WSC.

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