scholarly journals Barotropic and baroclinic tidal currents on the Mackenzie shelf break in the southeastern Beaufort Sea

2004 ◽  
Vol 109 (C5) ◽  
Author(s):  
Evgueni A. Kulikov
Keyword(s):  
Beaufort Sea ◽  
Tidal Currents ◽  
Shelf Break ◽  
Mackenzie Shelf

Variability of baroclinic tidal currents on the Mackenzie Shelf, the Southeastern Beaufort Sea

2010 ◽  
Vol 30 (6) ◽  
pp. 656-667 ◽  
Author(s):  
Evgueni A. Kulikov ◽  
Alexander B. Rabinovich ◽  
Eddy C. Carmack
Keyword(s):  
Beaufort Sea ◽  
Tidal Currents ◽  
Mackenzie Shelf

A description of water types on the Mackenzie Shelf of the Beaufort Sea during winter

1992 ◽  
Vol 97 (C8) ◽  
pp. 12607 ◽  
Author(s):  
R. M. Moore ◽  
H. Melling ◽  
K. R. Thompson
Keyword(s):  
Beaufort Sea ◽  
Water Types ◽  
Mackenzie Shelf

scholarly journals Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea

2017 ◽  
Author(s):  
Jacoba Mol ◽  
Helmuth Thomas ◽  
Paul G. Myers ◽  
Xianmin Hu ◽  
Alfonso Mucci
Keyword(s):  
Sea Ice ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Beaufort Sea ◽  
Total Alkalinity ◽  
The Arctic ◽  
Surface Mixed Layer ◽  
Saturation State ◽  
Carbon Transfer ◽  
Mackenzie Shelf

Abstract. The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries inorganic carbon and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world oceans. Upwelling carries dissolved inorganic carbon (DIC) and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of inorganic carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of inorganic carbon are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) framework. A strong upwelling event prior to sampling on the Mackenzie Shelf is analyzed and the resulting influence on the carbonate system, including the saturation state of waters with respect to aragonite and pH, is investigated. TA and the oxygen isotope ratio of water (δ18O) are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of carbon dioxide (CO2) in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis for understanding how it will respond to the aforementioned climate-induced changes.

scholarly journals Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica

Ocean Science ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 77-93 ◽  
Author(s):  
Stefanie Semper ◽  
Elin Darelius
Keyword(s):  
Dispersion Curve ◽  
Austral Summer ◽  
Tidal Energy ◽  
Tidal Currents ◽  
Shelf Break ◽  
Weddell Sea ◽  
Austral Winter ◽  
Background Current ◽  
Trapped Waves ◽  
Coastal Trapped Waves

Abstract. The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with distance from it. The diurnal tidal energy increases from austral winter to summer by, on average, 50 %. The austral summer enhancement is observed in all deployments. The observations are compared to results from an idealised numerical solution of the properties of coastal trapped waves (CTWs) for a given bathymetry, stratification and an along-slope current. The frequency at which the dispersion curve for mode 1 CTWs displays a maximum (i.e. where the group velocity is zero and resonance is possible) is found within or near the diurnal frequency band, and it is sensitive to the stratification in the upper part of the water column and to the background current. The maximum of the dispersion curve is shifted towards higher frequencies, above the diurnal band, for weak stratification and a strong background current (i.e. austral winter-like conditions) and towards lower frequencies for strong upper-layer stratification and a weak background current (austral summer). The seasonal evolution of hydrography and currents in the region is inferred from available mooring data and conductivity–temperature–depth profiles. Near-resonance of diurnal tidal CTWs during austral summer can explain the observed seasonality in tidal currents.

The Structure of the Internal Tide at the Celtic Sea Shelf Break

1984 ◽  
Vol 64 (1) ◽  
pp. 99-113 ◽  
Author(s):  
R. D. Pingree ◽  
D. K. Griffiths ◽  
G. T. Mardell
Keyword(s):  
Simple Model ◽  
Internal Tide ◽  
Tidal Currents ◽  
Shelf Break ◽  
Progressive Wave ◽  
Celtic Sea

Measurements at sea in the Biscay and Celtic Sea have shown that the peak to trough displacement of the internal tide maximises at the shelf break of the Celtic Sea with peak to trough values in excess of 50 m at spring tides during the summer. In this region the internal tide generated at the top of the slopes is highly distorted by the shelf barotropic tidal currents. The internal tide propagates on-shelf towards the coast and off-slope towards the ocean as a decaying progressive wave. A simple model is developed that illustrates many of the observed features of the measured structure of the internal tide.

Distribution of dinoflagellate cysts in surface sediments of the Mackenzie Shelf and Amundsen Gulf, Beaufort Sea (Canada)

2008 ◽  
Vol 74 (3-4) ◽  
pp. 825-839 ◽  
Author(s):  
Thomas Richerol ◽  
André Rochon ◽  
Steve Blasco ◽  
Dave B. Scott ◽  
Trecia M. Schell ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Beaufort Sea ◽  
Dinoflagellate Cysts ◽  
Mackenzie Shelf ◽  
Amundsen Gulf

scholarly journals Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica

2016 ◽  
Author(s):  
Stefanie Semper ◽  
Elin Darelius
Keyword(s):  
Dispersion Curve ◽  
Austral Summer ◽  
Tidal Currents ◽  
Shelf Break ◽  
Weddell Sea ◽  
Background Current ◽  
Trapped Waves ◽  
Coastal Trapped Waves ◽  
Near Resonance ◽  
Temperature Depth

Abstract. The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with distance; its magnitude increases from austral winter to summer by on average 50 %. The summer enhancement is observed in all deployments. The observations are compared to results from an idealised numerical solution of the properties of coastal trapped waves (CTWs) for a given bathymetry, stratification and an along-slope current. The frequency at which the dispersion curve for mode 1 CTWs displays a maximum (i.e. where the group velocity is zero and resonance is possible) is found within or near the diurnal frequency band, and it is sensitive to the stratification in the upper part of the water column and to the background current. The maximum of the dispersion curve is shifted towards higher frequencies, above the diurnal band, for low stratification and a strong background current (i.e. winter-like conditions) and towards lower frequencies for strong upper layer stratification and a weak background current (summer). The seasonal evolution of hydrography and currents in the region is inferred from available mooring data and conductivity-temperature-depth profiles. Near-resonance between CTWs and the diurnal tides during austral summer can explain the observed seasonality in tidal currents.

scholarly journals Patterns of suspended particulate matter across the continental margin in the Canadian Beaufort Sea during summer

2019 ◽  
Vol 16 (7) ◽  
pp. 1583-1605 ◽  
Author(s):  
Jens K. Ehn ◽  
Rick A. Reynolds ◽  
Dariusz Stramski ◽  
David Doxaran ◽  
Bruno Lansard ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Sea Ice ◽  
Suspended Particulate Matter ◽  
Continental Margin ◽  
Suspended Particle ◽  
Particle Diameter ◽  
Beaufort Sea ◽  
Shelf Break ◽  
Return Flow ◽  
Suspended Particulate

Abstract. The particulate beam attenuation coefficient at 660 nm, cp(660), was measured in conjunction with properties of suspended particle assemblages in August 2009 within the Canadian Beaufort Sea continental margin, a region heavily influenced by freshwater and sediment discharge from the Mackenzie River, but also by sea ice melt. The mass concentration of suspended particulate matter (SPM) ranged from 0.04 to 140 g m−3, its composition varied from mineral to organic dominated, and the median particle diameter determined over the range 0.7–120 µm varied from 0.78 to 9.45 µm, with the fraction of particles <1 µm in surface waters reflecting the degree influenced by river water. Despite this range in particle characteristics, a strong relationship between SPM and cp(660) was found and used to determine SPM distributions across the shelf based on measurements of cp(660) taken during summer seasons of 2004, 2008, and 2009. SPM spatial patterns on the stratified shelf reflected the vertically sheared two-layer estuarine circulation and SPM sources (i.e., fluvial inputs, bottom resuspension, and biological productivity). Along-shelf winds generated lateral Ekman flows, isopycnal movements, and upwelling or downwelling at the shelf break. Cross-shelf transects measured during three summers illustrate how sea ice meltwater affects river plume extent, while the presence of meltwater on the shelf was associated with enhanced near-bottom SPM during return flow of upwelled Pacific-origin water. SPM decreased sharply past the shelf break with further transport of particulate matter occurring near the bottom and in interleaving nepheloid layers. These findings expand our knowledge of particle distributions in the Beaufort Sea controlled by river discharge, sea ice, and wind, each of which is sensitive to weather and climate variations.

Current surges and seabed erosion near the shelf break in the Canadian Beaufort Sea: A response to wind and ice motion stress

2016 ◽  
Vol 160 ◽  
pp. 1-16 ◽  
Author(s):  
Alexandre Forest ◽  
Philip D. Osborne ◽  
Gregory Curtiss ◽  
Malcolm G. Lowings
Keyword(s):  
Beaufort Sea ◽  
Shelf Break
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