Late Quaternary paleoceanography of the western Baffin Bay region: evidence from fossil diatoms

1990 ◽  
Vol 27 (11) ◽  
pp. 1487-1494 ◽  
Author(s):  
Kerstin M. Williams
Keyword(s):  
Sea Ice ◽  
East Coast ◽  
Late Quaternary ◽  
Baffin Island ◽  
Ocean Water ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
Oceanographic Variables ◽  
Diatom Productivity ◽  
Fossil Diatoms

Seven marine cores from the east coast of Baffin Island were examined for variations in diatom content. The cores have good age control and were used for Holocene paleoceanographic reconstruction. A diatom barren zone or a zone of much reduced diatom productivity is evident some time during the early to middle Holocene. This zone ends earlier in the southern area than farther north. The changes in diatom productivity may be caused by changing oceanographic variables such as sea ice extent and the presence of a meltwater cap during deglaciation. Light isotope 18O events ("meltwater spikes") generally coincide with barren or reduced productivity zones in the cores from the middle and southern part of the shelf and from Jones Sound, suggesting a general surficial cooling of the fjord and ocean water. If diatom productivity was depressed because of a meltwater cap over the core sites with increasing sea ice extent, the theory of a general "marine optimum" in all of Baffin Bay and Davis Strait from 8000 to 6000 BP may have to be modified.

scholarly journals Late Quaternary Marine and Terrestrial Environments, Northwestern Baffin Island, Northwest Territories

2007 ◽  
Vol 48 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Susan K. Short ◽  
John T. Andrews ◽  
Kerstin M. Williams ◽  
Nancy J. Weiner ◽  
Scott A. Elias
Keyword(s):  
Sea Ice ◽  
Late Quaternary ◽  
Major Change ◽  
Local Environment ◽  
High Arctic ◽  
Baffin Island ◽  
Radiocarbon Dates ◽  
Terrestrial Environments ◽  
Ice Conditions ◽  
Diatom Productivity

ABSTRACT Paleoenvironmental data were analyzed from terrestrial, lake, and marine sediments collected near Arctic Bay, Baffin Island, N.W.T. Eighteen new radiocarbon dates provide chronological control, superseding earlier results. Spuriously old dates were obtained from both sandy peats and low-organic lake sediments. The most reliable dates were from marine shells and foraminifera. They indicate that déglaciation was underway by 9000 BP rather than 16,000 BP. Over the period of the record, the local environment was characterized by a high arctic pollen assemblage dominated by grass, sedge, and willow; a middle Holocene warm period is indicated by increased willow, herb, and moss values. Sea-ice conditions were severe enough to inhibit the growth of diatoms until ca. 6300 BP and ice proximal and deglacial conditions prevailed in the fiords until ca. 6000 BP. Diatom productivity increased between 3000 BP and 2500 BP, suggesting warmer surface waters and less sea ice. After 2000 BP diatom accumulation decreased sharply, due to a cooling of climate. The foraminifera indicate a major change in bottom water conditions ca. 4000 BP as the benthic species shift from a calcareous to an arenaceous assemblage.

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.

scholarly journals The anomalous sea‐ice extent in Hudson bay, Baffin bay and the Labrador sea during three simultaneous NAO and ENSO episodes

1996 ◽  
Vol 34 (2) ◽  
pp. 313-343 ◽  
Author(s):  
L.A. Mysak ◽  
R.G. Ingram ◽  
J. Wang ◽  
A. van der Baaren
Keyword(s):  
Sea Ice ◽  
Labrador Sea ◽  
Hudson Bay ◽  
Sea Ice Extent ◽  
Baffin Bay

scholarly journals Bridging perspectives from remote Sensing and Inuit communities on changing Sea-ice cover in the Baffin Bay region

2006 ◽  
Vol 44 ◽  
pp. 433-438 ◽  
Author(s):  
Walter N. Meier ◽  
Julienne Stroeve ◽  
Shari Gearheard
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Local Level ◽  
Indigenous Communities ◽  
Passive Microwave ◽  
Regional Variability ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
Inuit Knowledge ◽  
Arctic Summer

AbstractPassive microwave imagery indicates a decreasing trend in Arctic Summer Sea-ice extent Since 1979. The Summers of 2002–05 have exhibited particularly reduced extent and have reinforced the downward trend. Even the winter periods have now Shown decreasing trends. At the local level, Arctic residents are also noticing changes in Sea ice. In particular, indigenous elders and hunters report changes Such as earlier break-up, later freeze-up and thinner ice. The changing conditions have profound implications for Arctic-wide climate, but there is also regional variability in the extent trends. These can have important ramifications for wildlife and indigenous communities in the affected regions. Here we bring together observations from remote Sensing with observations and knowledge of Inuit who live in the Baffin Bay region. Weaving the complementary perspectives of Science and Inuit knowledge, we investigate the processes driving changes in Baffin Bay Sea-ice extent and discuss the present and potential future effects of changing Sea ice on local activities.

scholarly journals Warming of the Polar Water Layer in Disko Bay and Potential Impact on Jakobshavn Isbrae

2013 ◽  
Vol 43 (12) ◽  
pp. 2629-2640 ◽  
Author(s):  
Paul G. Myers ◽  
Mads H. Ribergaard
Keyword(s):  
East Coast ◽  
Heat Content ◽  
Water Layer ◽  
Ocean Water ◽  
The West ◽  
Tidewater Glaciers ◽  
Baffin Bay ◽  
Coastal Shelf ◽  
Potential Impact ◽  
Polar Water

Abstract A number of recent studies have shown enhanced retreat of tidewater glaciers over much of southern and western Greenland. One of the fastest retreats has occurred at Jakobshavn Isbrae, with the rapid retreat linked to the arrival of relatively warm and saline Irminger water along the west coast of Greenland. Similar links to changes in ocean water masses on the coastal shelf of Greenland were also seen on the east coast. This study presents hydrographic data from Disko Bay, additionally revealing that there was also a significant warming of the cold polar water entering Disko Bay from the mid-to-late 1990s onward. This layer, which lies at a depth of ~30–200 m, warmed by 1°–2°C. The heat content of the polar water layer increased by a factor of 3.6 for the post-1997 period compared to the period prior to 1990. The heat content in the west Greenland Irminger water layer between the same periods increased only by a factor of 2, but contained more total heat. The authors suggest that the changes in the polar water layer are related to circulation changes in Baffin Bay.

scholarly journals Climate information preserved in seasonal water isotope at NEEM: relationships with temperature, circulation and sea ice

2018 ◽  
Author(s):  
Minjie Zheng ◽  
Jesper Sjolte ◽  
Florian Adolphi ◽  
Bo Møllesøe Vinther ◽  
Hans Christian Steen-Larsen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Ice Cores ◽  
Principal Component ◽  
Summer Precipitation ◽  
Satellite Observation ◽  
Climate Information ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
Baffin Bay

Abstract. Analyzing seasonally resolved δ18O ice core data can aid the interpretation of the climate information in ice cores, providing also insights into factors governing the δ18O signal that cannot be deciphered by investigating the annual δ18O data only. However, the seasonal isotope signal has not yet to be investigated in northern Greenland, e.g. at the NEEM (North Greenland Eemian Ice Drilling) ice core drill site. Here we analyze seasonally resolved δ18O data from four shallow NEEM ice cores covering the last 150 years. Based on correlation analysis with observed temperature, we attribute about 70 % and 30 % of annual accumulation to summer and winter respectively. The NEEM summer δ18O signal correlates strongly with summer western Greenland coastal temperature and with the first principal component (PC1) of summer δ18O from multiple seasonally resolved ice cores from central/southern Greenland. However, there are no significant correlations between NEEM winter δ18O data and western Greenland coastal winter temperature, or southern/central Greenland winter δ18O PC1. The stronger correlation with temperature during summer and the dominance of summer precipitation skew the annual δ18O signal in NEEM. The strong footprint of temperature in NEEM summer δ18O record also suggests that the summer δ18O record, rather than the winter δ18O record, is a better temperature proxy at the NEEM site. Despite dominant signal of North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO) in the central-southern ice cores data, both NAO and AMO exert weak influences on NEEM seasonal δ18O variations. The NEEM seasonal δ18O is found to be highly correlated with Baffin Bay sea ice concentration (SIC) in satellite observation period (1979–2004), suggesting a connection of the sea ice extent with δ18O at NEEM. NEEM winter δ18O significantly correlates with SIC even for the period prior to satellite observation (1901–1978). The NEEM winter δ18O may reflect sea ice variations of Baffin Bay rather than temperature itself. This study shows that seasonally resolved δ18O records, especially for sites with seasonal precipitation bias such as NEEM, provide a better understanding of how changing air temperature and circulation patterns are associated with the variability of the δ18O records.

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