scholarly journals Oceanic Boundary Conditions for Jakobshavn Glacier. Part II: Provenance and Sources of Variability of Disko Bay and Ilulissat Icefjord Waters, 1990–2011

2015 ◽  
Vol 45 (1) ◽  
pp. 33-63 ◽  
Author(s):  
Carl V. Gladish ◽  
David M. Holland ◽  
Craig M. Lee
Keyword(s):  
Atlantic Water ◽  
Temperature Cycle ◽  
Freshwater Flux ◽  
The West ◽  
Baffin Bay ◽  
West Greenland ◽  
Water Fraction ◽  
West Greenland Current ◽  
Current Water ◽  
Polar Water

AbstractJakobshavn Glacier, west Greenland, has responded to temperature changes in Ilulissat Icefjord, into which it terminates. Basin waters in this fjord exchange with neighboring Disko Bay waters of a particular density at least once per year. This study determined the provenance of this isopycnic layer for 1990–2011 using hydrographic data from Cape Farewell to Baffin Bay. The warm Atlantic-origin core of the West Greenland Current never filled deep Disko Bay or entered the fjord basin because of bathymetric impediments on the west Greenland shelf. Instead, equal parts of Atlantic water and less-saline polar water filled the fjord basin and bathed Jakobshavn Glacier. The polar water fraction was often traceable to the East/West Greenland Current but sometimes to the colder Baffin Current. The huge annual temperature cycle on West Greenland Current isopycnals did not propagate into deep Disko Bay or the fjord basin because isopycnals over the west Greenland shelf were depressed during the warm autumn/winter phase of the cycle.Ilulissat Icefjord basin waters were anomalously cool in summer 2010. This was not because of the record low NAO index winter of 2009/10 or atmospheric anomalies over Baffin Bay but, possibly, because of high freshwater flux through the Canadian Arctic and a weak West Greenland Current in early 2010. Together, this caused cold Baffin Current water to flood the west Greenland shelf. Subpolar gyre warming associated with the NAO anomaly in winter 2009/10 was more likely responsible for the record warm Disko Bay and Ilulissat Icefjord basin waters of 2011/12.

MARINE MACROPLANKTON FROM THE CANADIAN EASTERN ARCTIC: I. AMPHIPODA AND SCHIZOPODA

1942 ◽  
Vol 20d (1) ◽  
pp. 33-46 ◽  
Author(s):  
M. J. Dunbar
Keyword(s):  
High Arctic ◽  
Atlantic Water ◽  
Amphipod Species ◽  
Hydrographic Data ◽  
Baffin Bay ◽  
West Greenland ◽  
The Difference ◽  
Two Sides ◽  
A New Species ◽  
Polar Water

Twenty-four amphipod species (one a new species), three euphausiids, and two mysids are recorded from the coastal water of the Canadian eastern Arctic. Most of the records are new.The list is representative of a high arctic plankton, giving no evidence of the intrusion of Atlantic water. This is in agreement with the hydrographic observations made, and with available hydrographic data from other sources.The plankton is contrasted with that found in 1936 in Disko Bay, west Greenland, where there appears to be an upwelling of mixed Arctic and Atlantic water. The difference between the plankton of the two sides of Baffin Bay suggests the possibility of distinguishing water of Lancaster Sound (Canadian polar water) from that of west Greenland by means of their planktonic fauna.

Holocene water mass changes in the Labrador Current

The Holocene ◽  
2019 ◽  
Vol 29 (4) ◽  
pp. 676-690 ◽  
Author(s):  
Annalena Antonia Lochte ◽  
Janne Repschläger ◽  
Marit-Solveig Seidenkrantz ◽  
Markus Kienast ◽  
Thomas Blanz ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Productivity ◽  
Atlantic Water ◽  
Water Masses ◽  
Labrador Sea ◽  
The West ◽  
West Greenland ◽  
Labrador Current ◽  
Water Outflow ◽  
Polar Water

The Labrador Current is part of the anticlockwise subpolar gyre and plays a major role in the formation of North Atlantic Deep Water. It is influenced by the West Greenland and Baffin currents supplying warmer Atlantic and cold polar waters, respectively. During the early Holocene, at the final stage of the last deglaciation, meltwater and iceberg discharge caused highly variable conditions in the Labrador Current. In order to assess its sensitivity to such freshening, this study provides a well-resolved Holocene paleoclimatic record from the Labrador Shelf. Based on benthic foraminiferal faunal and alkenone biomarker analyses, we differentiated four distinct climatic periods in the western Labrador Sea. From 8.9 to 8.6 ka BP, the Labrador Shelf was dominated by polar water outflow from Baffin Bay and covered by perennial sea ice. Between 8.6 and 7.4 ka BP, a strong subsurface inflow of warmer Atlantic water masses is ascribed to an intensification and redirection of the West Greenland Current. At 7.4 ka BP, the decreased influence of Atlantic water masses on the Labrador Shelf marks the establishment of winter convection leading to the formation of Labrador Sea Water in the central basin. Concurrently, an intensified polar water outflow through the Canadian Gateways strengthened the inner Labrador Current, and higher primary productivity suggests longer spring blooms because of a shorter sea-ice season during the Holocene Thermal Maximum. In the late Holocene after 3 ka BP, periodic fluctuations of primary productivity may tentatively be correlated with stronger and weaker northwesterly winds.

scholarly journals Variable influx of West Greenland Current water into the Labrador Current through the last 7200 years: a multiproxy record from Trinity Bay (NE Newfoundland)

arktos ◽  
2015 ◽  
Vol 1 (1) ◽  
Author(s):  
C. M. Sheldon ◽  
M.-S. Seidenkrantz ◽  
P. Frandsen ◽  
H. V. Jacobsen ◽  
N. Van Nieuwenhove ◽  
...  
Keyword(s):  
West Greenland ◽  
West Greenland Current ◽  
Labrador Current ◽  
Current Water ◽  
Trinity Bay

scholarly journals Mean Conditions and Seasonality of the West Greenland Boundary Current System near Cape Farewell

2020 ◽  
Vol 50 (10) ◽  
pp. 2849-2871
Author(s):  
Astrid Pacini ◽  
Robert S. Pickart ◽  
Frank Bahr ◽  
Daniel J. Torres ◽  
Andrée L. Ramsey ◽  
...  
Keyword(s):  
Current System ◽  
Labrador Sea ◽  
Western Boundary ◽  
Coastal Current ◽  
Boundary Current ◽  
The West ◽  
West Greenland ◽  
Irminger Sea ◽  
West Greenland Current ◽  
Recirculation Gyre

AbstractThe structure, transport, and seasonal variability of the West Greenland boundary current system near Cape Farewell are investigated using a high-resolution mooring array deployed from 2014 to 2018. The boundary current system is comprised of three components: the West Greenland Coastal Current, which advects cold and fresh Upper Polar Water (UPW); the West Greenland Current, which transports warm and salty Irminger Water (IW) along the upper slope and UPW at the surface; and the Deep Western Boundary Current, which advects dense overflow waters. Labrador Sea Water (LSW) is prevalent at the seaward side of the array within an offshore recirculation gyre and at the base of the West Greenland Current. The 4-yr mean transport of the full boundary current system is 31.1 ± 7.4 Sv (1 Sv ≡ 106 m3 s−1), with no clear seasonal signal. However, the individual water mass components exhibit seasonal cycles in hydrographic properties and transport. LSW penetrates the boundary current locally, through entrainment/mixing from the adjacent recirculation gyre, and also enters the current upstream in the Irminger Sea. IW is modified through air–sea interaction during winter along the length of its trajectory around the Irminger Sea, which converts some of the water to LSW. This, together with the seasonal increase in LSW entering the current, results in an anticorrelation in transport between these two water masses. The seasonality in UPW transport can be explained by remote wind forcing and subsequent adjustment via coastal trapped waves. Our results provide the first quantitatively robust observational description of the boundary current in the eastern Labrador Sea.

scholarly journals Ice stream retreat following the LGM and onset of the west Greenland current in Uummannaq Trough, west Greenland

2016 ◽  
Vol 147 ◽  
pp. 27-46 ◽  
Author(s):  
Christina Sheldon ◽  
Anne Jennings ◽  
John T. Andrews ◽  
Colm Ó Cofaigh ◽  
Kelly Hogan ◽  
...  
Keyword(s):  
The West ◽  
West Greenland ◽  
Ice Stream ◽  
West Greenland Current

scholarly journals Origin and Composition of Seasonal Labrador Sea Freshwater

2007 ◽  
Vol 37 (6) ◽  
pp. 1445-1454 ◽  
Author(s):  
Sunke Schmidt ◽  
Uwe Send
Keyword(s):  
Time Scales ◽  
Late Summer ◽  
The Arctic ◽  
Labrador Sea ◽  
The West ◽  
East Greenland ◽  
West Greenland ◽  
Boundary Currents ◽  
East Greenland Current ◽  
West Greenland Current

Abstract The depth of winter convection in the central Labrador Sea is strongly influenced by the prevailing stratification in late summer. For this late summer stratification salinity is as important as temperature, and in the upper water layers salinity even dominates. To analyze the source of the spring and summer freshening in the central region, seasonal freshwater cycles have been constructed for the interior Labrador Sea, the West Greenland Current, and the Labrador Current. It is shown that none of the local freshwater sources is responsible for the spring–summer freshening in the interior, which appears to occur in two separate events in April to May and July to September. Comparing the timing and volume estimates of the seasonal freshwater cycles of the boundary currents with the central Labrador Sea helps in understanding the origin of the interior freshwater signals. The first smaller pulse cannot be attributed clearly to either of the boundary currents. The second one is about three times stronger and supplies 60% of the seasonal summer freshwater. Transport estimates and calculated mixing properties provide evidence that its source is the West Greenland Current. The finding implies a connection also on interannual time scales between Labrador Sea surface salinity and freshwater sources in the West Greenland Current and farther upstream in the East Greenland Current. The freshwater input from the West Greenland Current thus also is the likely pathway for the known modulation of Labrador Sea Water mass formation by freshwater export from the Arctic (via the East Greenland Current), which implies some predictability on longer time scales.

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.

An Index of the Relative Abundance of Wintering Belugas, Delphinapterus leucas, and Narwhals, Monodon monoceros, off West Greenland

1993 ◽  
Vol 50 (11) ◽  
pp. 2323-2335 ◽  
Author(s):  
M. P. Heide-Jørgensen ◽  
H. Lassen ◽  
J. Teilmann ◽  
R. A. Davis
Keyword(s):  
Relative Abundance ◽  
Delphinapterus Leucas ◽  
Late Winter ◽  
The West ◽  
Baffin Bay ◽  
West Greenland ◽  
Abundance Estimate ◽  
Monodon Monoceros ◽  
Pack Ice ◽  
Ice Conditions

Systematic aerial surveys of the wintering grounds of belugas, Delphinapterus leucas, and narwhals, Monodon monoceros, in southern Baffin Bay and northern Davis Strait were conducted in late winter of 1981, 1982, 1990, and 1991. Most belugas were found between 67°N and 69°N and none were seen more than 80 km off the coast of West Greenland. Compared with the surveys in 1981 and 1982, a decline in relative abundance of belugas along West Greenland was evident in 1991. This decline was significant at a probability level of 0.13 of the bootstrapped distribution of the combined abundance estimate. Pod sizes declined significantly between the 1981–82 and 1990–91 surveys. The variations in ice conditions between years did not seem to affect the distribution, clumping, or pod sizes of the belugas. Narwhals were widely distributed in the close pack ice offshore between 65°N and 72°N. Along the West Greenland coast, narwhals were primarily seen at the mouth of Disko Bay. No change in relative abundance or pod sizes could be detected for narwhals.

scholarly journals Irminger Water variability in the West Greenland Current

2007 ◽  
Vol 34 (17) ◽  
Author(s):  
Paul G. Myers ◽  
Nilgun Kulan ◽  
Mads H. Ribergaard
Keyword(s):  
The West ◽  
West Greenland ◽  
West Greenland Current
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