scholarly journals A case-study in tracking 1998 polynya ice dynamics in Smith Sound, North Water polynya region, Canadian Arctic, using RADARSAT-1 data

2001 ◽  
Vol 33 ◽  
pp. 413-418 ◽  
Author(s):  
K. J. Wilson ◽  
D. J. King ◽  
D. G. Barber
Keyword(s):  
Canadian Arctic ◽  
Ice Dynamics ◽  
The North ◽  
North Water Polynya ◽  
North Water ◽  
Oceanic Forcing ◽  
The Mean ◽  
Insight Into

AbstractMonitoring ice motion provides insight into the relative contributions of atmospheric and oceanic forcing to polynya dynamics In this study ice kinematics in the North Water (NOW) region, northern Baffin Bay Canadian Arctic are determined using time-sequential RADARSAT-1 ScanSARWide imagery (from the period January-December 1998), processed by the automated ice-tracking algorithm (Tracker) currently used at the Canadian Ice Service (CIS). A case-study is then carried out on the Smith Sound region from January till the end of june 1998 to monitor polynya formation, maintenance and disintegration. This has two objectives: (1) to evaluate satellite ice-motion products as a means of better understanding the relative contributions of latent- and sensible-heat mechanisms responsible for the formation and behaviour of the NOW polynya, and (2) to study the influence of winds on regional sea-ice motion. Derived ice-motion maps were validated using in situ ice beacons deployed onto floes in the NOW region during the 1998 ship-based science experiment. Tracker-derived displacement and directional regressions were 0.93 and 0.79, respectively, with a total standard error of 3.6 km in magnitude and 38.8° in direction. Analysis of monthly mean ice-motion maps shows that a significant export of ice occurs from the polynya. A comparison of weekly-averaged ice motion with the mean wind-field data suggests that ice export in Smith Sound is influenced by synoptic-scale atmospheric pressure systems.

scholarly journals Biomarker characterization of the North Water Polynya, Baffin Bay: Implications for local sea ice and temperature proxies

2021 ◽  
Author(s):  
David J. Harning ◽  
Brooke Holman ◽  
Lineke Woelders ◽  
Anne E. Jennings ◽  
Julio Sepúlveda
Keyword(s):  
Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
The North ◽  
North Water Polynya ◽  
Lipid Biomarker ◽  
North Water ◽  
Order Of Magnitude ◽  
Insight Into

Abstract. The North Water Polynya (NOW, Greenlandic Inuit: Pikialasorsuaq), Baffin Bay, is the largest polynya and one of the most productive regions in the Arctic. This area of thin to absent sea ice is a critical moisture source for local ice sheet sustenance and coupled with the inflow of nutrient-rich Arctic Surface Water, supports a diverse community of Arctic fauna and indigenous people. Although paleoceanographic records can provide critical insight into the NOW’s past behavior, it is critical that we fully understand the modern functionality of the paleoceanographic proxies beforehand. In this study, we analyzed lipid biomarkers, including algal highly-branched isoprenoids and sterols for sea ice extent and pelagic productivity, and algal alkenones and archaeal GDGTs for ocean temperature, in a suite of modern surface sediment samples from within and around the NOW. Our data show that all highly-branched isoprenoids exhibit strong correlations with each other and show highest concentrations within the NOW, which suggests a spring/autumn sea ice diatom source rather than a combination of sea ice and open water diatoms as seen elsewhere in the Arctic. Sterols are also highly concentrated in the NOW and exhibit an order of magnitude higher concentration here compared to sites south of the NOW, consistent with the order of magnitude higher primary productivity observed within the NOW relative to surrounding waters in spring/summer months. Finally, our temperature calibrations for alkenones, GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations, but also identify some additional variables that may be important in controlling their local distribution, such as salinity, nutrients, and dissolved oxygen. Collectively, our datasets provide new insight into the utility of these lipid biomarker proxies in high-latitude settings and will help provide a refined perspective on the Holocene development of the NOW with their application in downcore reconstructions.

Behaviour of ringed seals tagged with satellite transmitters in the North Water polynya during fast-ice formation

1999 ◽  
Vol 77 (12) ◽  
pp. 1934-1946 ◽  
Author(s):  
Jonas Teilmann ◽  
Erik W Born ◽  
Mario Acquarone
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Baffin Island ◽  
The North ◽  
North Water Polynya ◽  
Ringed Seals ◽  
North Water ◽  
Satellite Transmitters ◽  
Fast Ice ◽  
Insight Into

To gain insight into the use by ringed seals (Phoca hispida) of the North Water polynya (northern Baffin Bay), we monitored the movements and diving behaviour of eight ringed seals caught in the fjords of the Thule (Avernarsuaq) area in Northwest Greenland. The animals were caught in August-September 1996 and equipped with satellite transmitters. Contact with the seals was maintained for up to 146 days. Two of the seals left the study area soon after being equipped, one moved north to the Kane Basin and one moved to southeastern Baffin Island. The departure of the other six seals from the fjords was apparently related to the formation of landfast ice. After formation of the polynya, all positions were close to the edge of the fast ice in the Thule area. Of the six seals that stayed in the North Water, three females preferred areas with shallow water (<100 m), while three males with larger body mass remained mainly in areas with deeper waters (>100 m). The "shallow-water" seals dove significantly more frequently to depths of less than 50 m than the "deep-water" seals, whereas the deep-water seals made significantly more dives that were deeper than 50 m. However, all seals occasionally dove to depths of more than 250 m.

scholarly journals An Examination of the Non-Formation of the North Water Polynya Ice Arch

2020 ◽  
Vol 12 (17) ◽  
pp. 2712
Author(s):  
Ron F. Vincent
Keyword(s):  
Ice Dynamics ◽  
Nares Strait ◽  
The North ◽  
North Water Polynya ◽  
Tidal Forces ◽  
Warming Climate ◽  
Northern Border ◽  
Key Factor ◽  
North Water ◽  
First Time

The North Water (NOW), situated between Ellesmere Island and Greenland in northern Baffin Bay, is the largest recurring polynya in the Canadian Arctic. Historically, the northern border of the NOW is defined by an ice arch that forms annually in Kane Basin, which is part of the Nares Strait system. In 2007 the NOW ice arch failed to consolidate for the first time since observations began in the 1950s. The non-formation of the NOW ice arch occurred again in 2009, 2010, 2017 and 2019. Satellite Advanced Very High Resolution Radiometry data shows that large floes broke off from the normally stable landfast ice in Kane Basin for each of these years, impeding ice arch formation. A closer analysis of a 2019 event, in which 2500 km2 of ice sheared away from Kane Basin, indicates that significant tidal forces played a role. The evidence suggests that thinning ice from a warming climate combined with large amplitude tides is a key factor in the changing ice dynamics of the NOW region. The non-formation of the NOW ice arch results in an increased loss of multiyear ice through Nares Strait.

scholarly journals Horizontal Movement of Fast Ice in the North Water Area

1977 ◽  
Vol 19 (81) ◽  
pp. 547-554 ◽  
Author(s):  
Hajime Ito ◽  
Fritz Müller
Keyword(s):  
Sea Ice ◽  
Water Area ◽  
Physical Characteristics ◽  
Stress Strain ◽  
Horizontal Movement ◽  
The North ◽  
North Water ◽  
Fast Ice ◽  
External Forces

AbstractThe understanding of the horizontal movement of fast ice is important for applied sea-ice mechanics. A case study, carried out in conjunction with a polynya known as North Water, is presented in this paper. The displacements of the fast-ire arches which separate the polynya from the surrounding ice-covered sea, were measured and found to be small. It is, therefore, confirmed that these arches prevent the influx of large quantities of sea ice into the polynya. The results are then explained in terms of the external forces (wind and current), the stress- strain situations and some physical characteristics (temperature and thickness) which were measured simultaneously.

scholarly journals Fuel economy assessment tool for auxiliary kite propulsion of merchant ship

2018 ◽  
pp. 5-7 ◽  
Author(s):  
Vincent Podeur ◽  
Damien Merdrignac ◽  
Morgan Behrel ◽  
Kostia Roncin ◽  
Caroline Fonti ◽  
...  
Keyword(s):  
Fuel Economy ◽  
Assessment Tool ◽  
Round Trip ◽  
Merchant Ship ◽  
Added Resistance In Waves ◽  
The Mean ◽  
The Impact ◽  
Engine Power

A tool dedicated to assess fuel economy induced by kite propulsion has been developed. To produce reliable results, computations must be performed on a period over several years, for several routes and for several ships. In order to accurately represent the impact of meteorological trends variations on the exploitability of the kite towing concept, a time domain approach of the problem has been used. This tool is based on the weather database provided by the ECMWF. Two sailing strategies can be selected for assessing the performance of the kite system. For a given kite area, the simulation can be run either at constant speed or at constant engine power. A validation has been made, showing that predicted consumption is close from in-situ measurement. It shows an underestimation of 11.9% of the mean fuel consumption mainly due to auxiliary consumption and added resistance in waves that were not taken into account. To conclude, a case study is performed on a 2200 TEU container ship equipped with an 800m² kite on a transatlantic route between Halifax and Le Havre. Round trip simulations, performed over 5 years of navigation, show that the total economy predicted is of around 12% at a speed of 16 knots and around 6.5% at a speed of 19 knots.

scholarly journals Living at a High Arctic Polynya: Inughuit Settlement and Subsistence around the North Water during the Thule Station Period, 1910–53

ARCTIC ◽  
2016 ◽  
Vol 69 (5) ◽  
pp. 1 ◽  
Author(s):  
Bjarne Grønnow
Keyword(s):  
Raw Materials ◽  
High Arctic ◽  
Ringed Seal ◽  
Site Location ◽  
Ice Cap ◽  
The North ◽  
North Water Polynya ◽  
Annual Range ◽  
North Water ◽  
The Rich

The settlement and subsistence patterns of the Inughuit of the Avanersuaq (Thule area) are described and analyzed for the years 1910 to 1953, when Knud Rasmussen’s trading station at Dundas was active. Inughuit subsistence was based on the rich biotic resources of the North Water polynya between Ellesmere Island and Greenland, but the analysis shows that trade, primarily with fox furs at the Thule Station, also played a major role in shaping the settlement pattern of the period. During the Thule Station Period, the named winter settlements amounted to c. 40 sites; however, only 10–15 of them were settled at any given time. The Inughuit settlement close to the station, Uummannaq, soon became the largest site in the area. The sources enable us to follow changes of residence of some hunting families over four decades. By moving their winter sites every second or third year, the families gained primary knowledge of the topography and seasonal variation of the hunting grounds in the entire Thule district during their active years. In the same way, they connected with diverse family networks through the years. Tracing the sledge routes that connected the sites over great distances reveals how decisive proximity to main and escape routes over the Ice Cap was for site location. Dog sledge technology, and thus capacity to transport people, gear, and stored food, boomed during the Thule Station Period with the wealth created from trade and access to raw materials. Mapping the main hunting grounds on the sea ice and modeling the hunters’ annual range of possibilities for accessing different game—mainly walrus, ringed seal, narwhal, and sea birds (plus some caribou)—showed that ringed seal formed the bread and butter of the subsistence economy. However, bulk resources, gained in particular from intensive spring walrus hunts at a few hot spots, as well as carefully timed consumption and sharing of the stored meat and blubber, were keys to life at the North Water polynya. Temporary settlement at the trading stations in the area—a couple of winters at a time—was also part of the risk management strategy of the Inughuit.

scholarly journals Global Art Market in the Aftermath of COVID-19: A Case Study on the United Arab Emirates

Arts ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 59
Author(s):  
Eve Grinstead
Keyword(s):  
United Arab Emirates ◽  
Art Market ◽  
Institutional Structures ◽  
Art Scene ◽  
The 2008 Financial Crisis ◽  
Global Art ◽  
Insight Into ◽  
Rare Instance

How has COVID-19 affected the global art market? This virus interrupted 2020 in unforeseen ways globally, including the cancellation of the most important art events of the year. Through a close chronological study of the Emirati art scene’s response, both in commercial and noncommercial venues, this essay explains how, and why, the UAE’s art scene was able to react quickly and perhaps more effectively than that of other nations, and what that means for its future. Based on fieldwork and press articles, this article posits that the Emirati art scene evolved from being virtually non-existent to a thriving contemporary art hub in a matter of decades because it has always had to adapt to challenges such as nonexistent art infrastructure or the 2008 financial crisis. By studying the UAE, we find examples of exhibitions that quickly moved from being in situ to online, a rare instance of galleries and art auction house collaborating, government and institutional structures stepping up to support artists and galleries, and the renaissance of Art Dubai taking place in person in 2021 after being abruptly cancelled in 2020. This knowledge provides insight into how the global art market is changing to face the consequences of COVID-19.

Stratigraphy of the North Cliff section, Wellsch Valley site, Saskatchewan

1988 ◽  
Vol 25 (2) ◽  
pp. 206-214 ◽  
Author(s):  
William C. Mahaney ◽  
A. MacS. Stalker
Keyword(s):  
Surface Soil ◽  
Element Composition ◽  
Sediment Chemistry ◽  
Distinctive Features ◽  
Centre Of Gravity ◽  
The North ◽  
Mn Content ◽  
The Mean ◽  
Valley Site

Eight separate till sheets are displayed at the North Cliff, which is part of the Wellsch Valley site in Saskatchewan. Those tills are differentiated by using physical characteristics, particle size, clay and primary mineralogy, and sediment chemistry. Grain size tends to fine downward in the section, and a significant increase in the mean [Formula: see text] centre of gravity indicates that some weathering occurred after deposition of the tills. Within the clay mineral suites, smectite tends to dominate in all eight tills, indicating that the paleoclimate was generally as dry as the present-day climate. Only till number 4 (counting from the bottom) contains halloysite; this halloysite may have been entrained from a preweathered surface by the glacier, or it may have formed in situ following deposition. Among the primary minerals, quartz dominates throughout the section, whereas plagioclases are least abundant in tills 4 and 5, possibly as a result of postdepositional weathering. Element composition shows only minor changes for Cu, Pb, Zn, Co, and Ni, whereas Mo increases upward in the section, Cr remains uniform in tills 1, 2, 3, 7, and 8 but increases slightly in tills 4–6, and Mn increases downward, possibly as a response to fluctuating amounts of groundwater. Till 4 forms the best stratigraphic marker in the sequence because of its high Mn content and the presence of halloysite, but till 5 also contains distinctive features in its element composition.The clay composition of the surface soil, which has formed in the top till since the departure of the last glacier, resembles that found in the underlying tills, whereas quartz and plagioclase are present in lesser amounts. These properties reflect both weathering in a semiarid climate and the presence of preweathered material from earlier paleosols.

Visiting the horned serpent’s home: A relational analysis of Paquimé as a pilgrimage site in the North American Southwest

2018 ◽  
Vol 18 (3) ◽  
pp. 306-324 ◽  
Author(s):  
Todd L VanPool ◽  
Christine S VanPool
Keyword(s):  
American Southwest ◽  
Casas Grandes ◽  
The Past ◽  
The North ◽  
Relational Perspective ◽  
Architectural Features ◽  
The Dead ◽  
North American Southwest ◽  
Insight Into

Paquimé, Chihuahua, was the ceremonial center of the Medio period (AD 1200 to 1450) Casas Grandes world, and the focus of regional pilgrimages. We use a relational perspective to explore the connections that were created and expressed during the pilgrimage. We propose that Paquimé was considered a living city, and that pilgrims actively supported its vitality through offerings of marine shells and other symbolically important goods. A region-wide network of signal fires centered on Cerro de Moctezuma, a hill directly overlooking Paquimé, summoned pilgrims. Ritual negotiations also focused on the dead and may have included at least occasional human sacrifice. While the pilgrimages focused on water-related ritual, they also included community and elite competition as reflected in architectural features such as the ball courts. Central to the pilgrimage was negotiation with the horned serpent, a deity that controlled water and was associated with leadership throughout Mesoamerica and the Southwest. The horned serpent is the primary supernatural entity reflected at the site and in the pottery pilgrims took with them back to their communities. Thus, the pilgrimages were times when the Casas Grandes people created and transformed their relationships with each other, religious elites, the dead, the landscape, and the horned serpent. These relationships in turn are reflected across the region (e.g., the broad distribution of Ramos Polychrome). This case study consequently demonstrates the potential that the relational perspective presented throughout this issue has for providing insight into the archaeological record and the past social structures it reflects.

The formation and maintenance of the North Water Polynya

2003 ◽  
Vol 41 (3) ◽  
pp. 187-201 ◽  
Author(s):  
T. Yao ◽  
C. L. Tang
Keyword(s):  
The North ◽  
North Water Polynya ◽  
North Water
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