Hydrographic Changes in Nares Strait (Canadian Arctic Archipelago) in Recent Decades Based on δ18O Profiles of Bivalve Shells

ARCTIC ◽  
2011 ◽  
Vol 64 (1) ◽  
pp. 45 ◽  
Author(s):  
Marta E. Torres ◽  
Daniela Zima ◽  
Kelly K. Falkner ◽  
Robie W. Macdonald ◽  
Mary O'Brien ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
The Arctic ◽  
Past Century ◽  
Depth Range ◽  
Baffin Bay ◽  
Nares Strait ◽  
The North ◽  
The Arctic Ocean ◽  
Oxygen Isotopic ◽  
Bivalve Shells

<span style="font-family: 'Times New Roman';">Nares Strait is one of three main passages of the Canadian Archipelago that channel relatively fresh seawater from the Arctic Ocean through Baffin Bay to the Labrador Sea. Oxygen isotopic profiles along the growth axis of bivalve shells, collected live over the 5 – 30 m depth range from the Greenland and Ellesmere Island sides of the strait, were used to reconstruct changes in the hydrography of the region over the past century. The variability in oxygen isotope ratios is mainly attributed to variations in salinity and suggests that the northern end of Nares Strait has been experiencing an increase in freshwater runoff since the mid 1980s. The recent changes are most pronounced at the northern end of the strait and diminish toward the south, a pattern consistent with proximity to the apparently freshening Arctic Ocean source in the north and mixing with Baffin Bay waters as the water progresses southward. This increasing freshwater signal may reflect changes in circulation and ice formation that favor an increased flow of relatively fresh waters from the Arctic Ocean into Nares Strait. </span>

scholarly journals Interpretation of Slar Imagery of Sea Ice in Nares Strait and the Arctic Ocean

1975 ◽  
Vol 15 (73) ◽  
pp. 193-213
Author(s):  
Moira Dunbar
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
North Pole ◽  
The Arctic ◽  
Canadian Forces ◽  
Nares Strait ◽  
The North ◽  
The Arctic Ocean ◽  
Ice Edge ◽  
Airborne Sensors

AbstractSLAR imagery of Nares Strait was obtained on three flights carried out in. January, March, and August of 1973 by Canadian Forces Maritime Proving and Evaluation Unit in an Argus aircraft equipped with a Motorola APS-94D SLAR; the March flight also covered two lines in the Arctic Ocean, from Alert 10 the North Pole and from the Pole down the long. 4ºE. meridian to the ice edge at about lat. 80º N. No observations on the ground were possible, but -some back-up was available on all flights from visual observations recorded in the air, and on the March flight from infrared line-scan and vertical photography.The interpretation of ice features from the SLAR imagery is discussed, and the conclusion reached that in spite of certain ambiguities the technique has great potential which will increase with improving resolution, Extent of coverage per distance flown and independence of light and cloud conditions make it unique among airborne sensors.

scholarly journals Interpretation of Slar Imagery of Sea Ice in Nares Strait and the Arctic Ocean

1975 ◽  
Vol 15 (73) ◽  
pp. 193-213 ◽  
Author(s):  
Moira Dunbar
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
North Pole ◽  
The Arctic ◽  
Canadian Forces ◽  
Nares Strait ◽  
The North ◽  
The Arctic Ocean ◽  
Ice Edge ◽  
Airborne Sensors

Abstract SLAR imagery of Nares Strait was obtained on three flights carried out in. January, March, and August of 1973 by Canadian Forces Maritime Proving and Evaluation Unit in an Argus aircraft equipped with a Motorola APS-94D SLAR; the March flight also covered two lines in the Arctic Ocean, from Alert 10 the North Pole and from the Pole down the long. 4ºE. meridian to the ice edge at about lat. 80º N. No observations on the ground were possible, but -some back-up was available on all flights from visual observations recorded in the air, and on the March flight from infrared line-scan and vertical photography. The interpretation of ice features from the SLAR imagery is discussed, and the conclusion reached that in spite of certain ambiguities the technique has great potential which will increase with improving resolution, Extent of coverage per distance flown and independence of light and cloud conditions make it unique among airborne sensors.

Atmospheric, oceanic, and sea-ice variability along Nares Strait: a numerical model study

2021 ◽  
Author(s):  
Yarisbel Garcia Quintana ◽  
Paul G. Myers ◽  
Kent Moore
Keyword(s):  
Numerical Model ◽  
Sea Ice ◽  
Arctic Ocean ◽  
North Atlantic ◽  
The Other ◽  
The Arctic ◽  
Nares Strait ◽  
The North ◽  
The Arctic Ocean ◽  
The North Atlantic

&lt;p&gt;Nares Strait, between Greenland and Ellesmere Island, is one of the main pathways connecting the Arctic Ocean to the North Atlantic. The multi-year sea ice that is transported through the strait plays an important role in the mass balance of Arctic sea-ice as well as influencing the climate of the North Atlantic region. This transport is modulated by the formation of ice arches that form at the southern and northern of the strait.&amp;#160; The arches also play an important role in the maintenance of the North Water Polynya (NOW) that forms at the southern end of the strait. The NOW is one of the largest and most productive of Arctic polynyas.&amp;#160;Given its significance, we use an eddy-permitting regional configuration of the Nucleus for European Modelling of the Ocean (NEMO) to explore sea-ice variability along Nares Strait, from 2002 to 2019.&amp;#160;The model is coupled with the Louvain-la-Neuve (LIM2) sea ice thermodynamic and dynamic numerical model and is forced by the Canadian Meteorological Centre&amp;#8217;s Global Deterministic Prediction System Reforecasts.&lt;/p&gt;&lt;p&gt;We use the model to explore the variability in ocean and sea ice characteristics along Nares Strait. The positive and negative degree days, measures of ice decay and growth, along the strait are consistent with the warming that the region is experiencing. Sea-ice production/decay did not show any significant change other than an enhanced decay during the summers of 2017-1019. Sea-ice thickness on the other hand has decreased significantly since 2007. This decrease has been more pronounced along the northern (north of Kane Basin) portion of the strait. What is more, ocean model data indicates that since 2007 the northern Nares Strait upper 100m layer has become fresher, indicating an increase in the freshwater export out of the Arctic Ocean and through the strait. The southern portion of the strait, on the other hand, has become warmer and saltier, which would be consistent with an influx of Irminger Water as proposed by previous modelling results. These changes could impact the formation and stability of the ice arch and hence the cessation of ice transport down Nares Strait as well as contributing to changes in the characteristics of the NOW.&amp;#160;&lt;/p&gt;

Oceanographic Features of the Canadian Archipelago

1957 ◽  
Vol 14 (5) ◽  
pp. 731-769 ◽  
Author(s):  
W. B. Bailey
Keyword(s):  
Arctic Ocean ◽  
Beaufort Sea ◽  
The Arctic ◽  
Temperature Structure ◽  
Vertical Temperature ◽  
Baffin Bay ◽  
The North ◽  
The Arctic Ocean ◽  
North Water ◽  
Ice Floes

Oceanographic data collected during the first cruise of H.M.C.S. Labrador to the Canadian Arctic in August and September 1954 permit comparisons of the vertical temperature and salinity structures in Baffin Bay, the Canadian Archipelago and the Arctic Ocean. From a comparison of the temperature–salinity characteristics of the waters in the Arctic Ocean (Beaufort Sea) with those in Baffin Bay, it is found that: (a) the surface waters of the Arctic Ocean are much less saline than those in Baffin Bay, but minimum temperatures are the same (−1.8 °C), (b) the waters of the upper 200 m. in Baffin Bay are denser than those found at corresponding depths in the Arctic Ocean, (c) below 200 m., Arctic waters are the denser, and below 500 m. they are denser than any waters found in Baffin Bay, and (d) waters found at 250 m. in the Beaufort Sea, at 500 m. in Smith Sound, and at 1250 m. in central Baffin Bay, have identical temperature and salinity characteristics (−0.3 °C., 34.4‰).In addition the data permitted limited investigations into the effect of drifting ice floes on the vertical temperature structure of the water, the origin of the "north water", long-term variations in the oceanographic conditions in Baffin Bay, and dynamic calculations of currents and volume transports of the waters through the channels leading into Baffin Bay.

scholarly journals Reconstruction of Holocene oceanographic conditions in the Northeastern Baffin Bay

2020 ◽  
Author(s):  
Katrine Elnegaard Hansen ◽  
Jacques Giraudeau ◽  
Lukas Wacker ◽  
Christof Pearce ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Atlantic Water ◽  
The Arctic ◽  
Subsurface Water ◽  
The Holocene ◽  
Baffin Bay ◽  
Nares Strait ◽  
The Arctic Ocean ◽  
Water Conditions

Abstract. The Baffin Bay is a semi-enclosed basin connecting the Arctic Ocean and the western North Atlantic, thus making out a significant pathway for heat exchange. Here we reconstruct the alternating advection of relatively warmer and saline Atlantic waters versus the incursion of colder Arctic water masses entering the Baffin Bay through the multiple gateways in the Canadian Arctic Archipelago and the Nares Strait during the Holocene. We carried out benthic foraminiferal assemblage analyses, X-Ray Fluorescence scanning and radiocarbon dating of a 738  cm long marine sediment core retrieved from the eastern Baffin Bay near Upernavik (Core AMD14-204C; 987m water depth). Results reveal that the eastern Baffin Bay was subjected to several oceanographic changes during the last 9.2 ka BP. Waning deglacial conditions with enhanced meltwater influxes and an extensive sea-ice cover prevailed in the eastern Baffin Bay from 9.2–7.9 ka BP. A transition towards bottom water ameliorations are recorded at 7.9 ka BP by increased advection of Atlantic water masses, encompassing the Holocene Thermal Maximum. A cold period with growing sea-ice cover at 6.7 ka BP interrupts the overall warm subsurface water conditions, promoted by a weaker northward flow of Atlantic waters. The onset of the Neoglaciation at ca. 2.9 ka BP, is marked by an abrupt transition towards a benthic fauna dominated by agglutinated species likely partly explained by a reduction of the influx of Atlantic water, allowing increased influx of the cold, corrosive Baffin Bay Deep Water originating from the Arctic Ocean, to enter the Baffin Bay through the Nares Strait. These cold subsurface water conditions persisted throughout the late Holocene, only interrupted by short-lived warmings superimposed on this cooling trend.

scholarly journals Reconstruction of Holocene oceanographic conditions in eastern Baffin Bay

2020 ◽  
Vol 16 (3) ◽  
pp. 1075-1095 ◽  
Author(s):  
Katrine Elnegaard Hansen ◽  
Jacques Giraudeau ◽  
Lukas Wacker ◽  
Christof Pearce ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Atlantic Water ◽  
The Arctic ◽  
Subsurface Water ◽  
The Holocene ◽  
Baffin Bay ◽  
Nares Strait ◽  
The Arctic Ocean ◽  
Water Conditions

Abstract. Baffin Bay is a semi-enclosed basin connecting the Arctic Ocean and the western North Atlantic, thus making out a significant pathway for heat exchange. Here we reconstruct the alternating advection of relatively warmer and saline Atlantic waters versus the incursion of colder Arctic water masses entering Baffin Bay through the multiple gateways in the Canadian Arctic Archipelago and the Nares Strait during the Holocene. We carried out benthic foraminiferal assemblage analyses, X-ray fluorescence scanning, and radiocarbon dating of a 738 cm long marine sediment core retrieved from eastern Baffin Bay near Upernavik, Greenland (Core AMD14-204C; 987 m water depth). Results reveal that eastern Baffin Bay was subjected to several oceanographic changes during the last 9.2 kyr. Waning deglacial conditions with enhanced meltwater influxes and an extensive sea-ice cover prevailed in eastern Baffin Bay from 9.2 to 7.9 ka. A transition towards bottom water amelioration is recorded at 7.9 ka by increased advection of Atlantic water masses, encompassing the Holocene Thermal Maximum. A cold period with growing sea-ice cover at 6.7 ka interrupts the overall warm subsurface water conditions, promoted by a weaker northward flow of Atlantic waters. The onset of the neoglaciation at ca. 2.9 ka is marked by an abrupt transition towards a benthic fauna dominated by agglutinated species, likely in part explained by a reduction of the influx of Atlantic Water, allowing an increased influx of the cold, corrosive Baffin Bay Deep Water originating from the Arctic Ocean to enter Baffin Bay through the Nares Strait. These cold subsurface water conditions persisted throughout the Late Holocene, only interrupted by short-lived warmings superimposed on this cooling trend.

Danian Mollusks from the Prince Creek Formation, Northern Alaska, and Implications for Arctic Ocean Paleogeography

1993 ◽  
Vol 67 (S35) ◽  
pp. 1-35 ◽  
Author(s):  
Louie Marincovich
Keyword(s):  
Arctic Ocean ◽  
World Ocean ◽  
Ocean Basin ◽  
The Arctic ◽  
The North ◽  
The World ◽  
The Arctic Ocean ◽  
Molluscan Fauna ◽  
Endemic Genera ◽  
Northern Alaska

The marine molluscan fauna of the Prince Creek Formation near Ocean Point, northern Alaska, is of Danian age. It is the only diverse and abundant Danian molluscan fauna known from the Arctic Ocean realm, and is the first evidence for an indigenous Paleocene shallow-water biota within a discrete Arctic Ocean Basin faunal province.A high percentage of endemic species, and two endemic genera, emphasize the degree to which the Arctic Ocean was geographically isolated from the world ocean during the earliest Tertiary. Many of the well-preserved Ocean Point mollusks, however, also occur in Danian faunas of the North American Western Interior, the Canadian Arctic Islands, Svalbard, and northwestern Europe, and are the basis for relating this Arctic Ocean fauna to that of the Danian world ocean.The Arctic Ocean was a Danian refugium for some genera that became extinct elsewhere during the Jurassic and Cretaceous. At the same time, this nearly landlocked ocean fostered the evolution of new taxa that later in the Paleogene migrated into the world ocean by way of the northeastern Atlantic. The first Cenozoic occurrences are reported for the bivalves Integricardium (Integricardium), Oxytoma (Hypoxytoma), Placunopsis, Tancredia (Tancredia), and Tellinimera, and the oldest Cenozoic records given for the bivalves Gari (Garum), Neilo, and Yoldia (Cnesterium). Among the 25 species in the molluscan fauna are four new gastropod species, Amauropsis fetteri, Ellipsoscapha sohli, Mathilda (Fimbriatella) amundseni, and Polinices (Euspira) repenningi, two new bivalve genera, Arcticlam and Mytilon, and 15 new bivalve species, Arcticlam nanseni, Corbula (Caryocorbula) betsyae, Crenella kannoi, Cyrtodaria katieae, Gari (Garum) brouwersae, Integricardium (Integricardium) keenae, Mytilon theresae, Neilo gryci, Nucula (Nucula) micheleae, Nuculana (Jupiteria) moriyai, Oxytoma (Hypoxytoma) hargrovei, Placunopsis rothi, Tancredia (Tancredia) slavichi, Tellinimera kauffmani, and Yoldia (Cnesterium) gladenkovi.

scholarly journals Carbon cycling in the Arctic Archipelago: the export of Pacific carbon to the North Atlantic

2009 ◽  
Vol 6 (1) ◽  
pp. 971-994 ◽  
Author(s):  
E. H. Shadwick ◽  
T. Papakyriakou ◽  
A. E. F. Prowe ◽  
D. Leong ◽  
S. A. Moore ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
North Atlantic ◽  
Barents Sea ◽  
Hydrological Cycle ◽  
Dissolved Inorganic Carbon ◽  
The Arctic ◽  
Co2 Uptake ◽  
The North ◽  
The Arctic Ocean ◽  
The North Atlantic

Abstract. The Arctic Ocean is expected to be disproportionately sensitive to climatic changes, and is thought to be an area where such changes might be detected. The Arctic hydrological cycle is influenced by: runoff and precipitation, sea ice formation/melting, and the inflow of saline waters from Bering and Fram Straits and the Barents Sea Shelf. Pacific water is recognizable as intermediate salinity water, with high concentrations of dissolved inorganic carbon (DIC), flowing from the Arctic Ocean to the North Atlantic via the Canadian Arctic Archipelago. We present DIC data from an east-west section through the Archipelago, as part of the Canadian International Polar Year initiatives. The fractions of Pacific and Arctic Ocean waters leaving the Archipelago and entering Baffin Bay, and subsequently the North Atlantic, are computed. The eastward transport of carbon from the Pacific, via the Arctic, to the North Atlantic is estimated. Altered mixing ratios of Pacific and freshwater in the Arctic Ocean have been recorded in recent decades. Any climatically driven alterations in the composition of waters leaving the Arctic Archipelago may have implications for anthropogenic CO2 uptake, and hence ocean acidification, in the subpolar and temperate North Atlantic.

Radiogenic Isotope Signatures of Holocene Sediments from Kane Basin: Linkage with the Re-opening and Evolution of Nares Strait

2021 ◽  
Author(s):  
Lina Madaj ◽  
Friedrich Lucassen ◽  
Claude Hillaire-Marcel ◽  
Simone A. Kasemann
Keyword(s):  
Ellesmere Island ◽  
The Arctic ◽  
Baffin Bay ◽  
Low Salinity ◽  
The Core ◽  
The Past ◽  
Nares Strait ◽  
The North ◽  
Sediment Input ◽  
Detrital Sediment

&lt;p&gt;The re-opening of the Arctic Ocean-Baffin Bay gateway through Nares Strait, following the Last Glacial Maximum, has been partly documented, discussed and revised in the past decades. The Nares Strait opening has led to the inception of the modern fast circulation pattern carrying low-salinity Arctic water towards Baffin Bay and further towards the Labrador Sea. This low-salinity water impacts thermohaline conditions in the North Atlantic, thus the Atlantic Meridional Overturning Circulation. Available land-based and marine records set the complete opening between 9 and 7.5&amp;#160;ka&amp;#160;BP [1-2], although the precise timing and intensification of the southward flowing currents is still open to debate. A recent study of a marine deglacial sedimentary record from Kane Basin, central Nares Strait, adds information about subsequent paleoceanographic conditions in this widened sector of the strait and proposed the complete opening at ~8.3&amp;#160;ka&amp;#160;BP [3].&lt;/p&gt;&lt;p&gt;We present complementary radiogenic strontium, neodymium and lead isotope data of the siliciclastic detrital sediment fraction of this very record [3] further documenting the timing and pattern of Nares Strait opening from a sediment provenance approach. The data permit to distinguish detrital material from northern Greenland and Ellesmere Island, transported to the core location from both sides of Nares Strait. Throughout the Holocene, the evolution of contributions of these two sources hint to the timing of the ice break-up in Kennedy Channel, north of Kane Basin, which led to the complete opening of Nares Strait [3]. The newly established gateway of material transported to the core location from the north via Kennedy Channel is recorded by increased contribution of northern Ellesmere Island detrital sediment input. This shift from a Greenland (Inglefield Land) dominated sediment input to a northern Ellesmere Island dominated sediment input supports the hypothesis of the newly proposed timing of the complete opening of Nares Strait at 8.3&amp;#160;ka&amp;#160;BP [3] and highlights a progressive trend towards modern-like conditions, reached at about 4&amp;#160;ka&amp;#160;BP.&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;[1] England (1999) Quaternary Science Reviews, 18(3), 421&amp;#8211;456. [2] Jennings et al. (2011) Oceanography, 24(3), 26-41. [3] Georgiadis et al. (2018) Climate of the Past, 14 (12), 1991-2010.&lt;/p&gt;

scholarly journals The Mass Balance of the Sea Ice of the Arctic Ocean

1973 ◽  
Vol 12 (65) ◽  
pp. 173-185 ◽  
Author(s):  
R. M. Koerner
Keyword(s):  
Arctic Ocean ◽  
Ablation Rate ◽  
The Arctic ◽  
First Year ◽  
The North ◽  
Ice Accumulation ◽  
The Pacific ◽  
The Arctic Ocean ◽  
Ridged Ice ◽  
Ice Production

AbstractFrom data taken on the British Trans-Arctic Expedition it is calculated that 9% of the Arctic Ocean surface between the North Pole and Spitsbergen was hummocked or ridged ice, 17% was unridged ice less than a year old, 73% was unridged old ice and 0.6% was ice-free. The mode of 250 thickness measurements taken through level areas of old floes along the entire traverse lies between 2.25 and 2.75 m. The mean end-of-winter thickness of the ice is calculated to be 4.6 m in the Pacific Gyral and 3.9 m in the Trans-Polar Drift Stream. From measurements of the percentage coverage and thickness of the various ice forms, it is calculated that the total annual ice accumulation in the Arctic Ocean is equivalent to a continuous layer of ice 1.1 m thick. 47% of this accumulation occurs in ice-free areas and under ice less than 1 year old. 20% of the total ice production is either directly or indirectly related to ridging or hummocking. An ice-ablation rate of 500 kg m−2 measured on a level area of a multi-year floe is compared with the rate on deformed and ponded ice. Greatest melting occurs on new hummocks and least on old smooth hummocks. The annual balance of ice older than 1 year but younger than multi-year ice is calculated from a knowledge of ice-drift patterns and the percentage coverage of first-year ice. The same calculations give a mean-maximum drift period of 5 years for ice in the Trans-Polar Drift Stream and 16 years in the Pacific Gyral. It is calculated that for the period February 1968 to May 1969 the annual ice export was 5 580 km3.

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