Role of Greenland Sea Gyre Circulation on Atlantic Water Temperature Variability in the Fram Strait

2018 ◽  
Vol 45 (16) ◽  
pp. 8399-8406 ◽  
Author(s):  
Sourav Chatterjee ◽  
Roshin P. Raj ◽  
L. Bertino ◽  
Ø. Skagseth ◽  
M. Ravichandran ◽  
...  
Keyword(s):  
Water Temperature ◽  
Atlantic Water ◽  
Temperature Variability ◽  
Fram Strait ◽  
Greenland Sea ◽  
Gyre Circulation

Large-scale connections between Fram Strait recirculation and warm water pathways towards Greenland fjords

2021 ◽  
Author(s):  
Rebecca McPherson ◽  
Torsten Kanzow ◽  
Claudia Wekerle
Keyword(s):  
Large Scale ◽  
Atlantic Water ◽  
Ocean Model ◽  
Intermediate Water ◽  
Fram Strait ◽  
The Past ◽  
Subsurface Waters ◽  
West Spitsbergen ◽  
Annual Time

<p>In the last two decades, rising ocean temperatures have significantly contributed to the increased melting and retreat of marine-terminating glaciers along the coast of Greenland. Warming subsurface waters have also been shown to interact with the glaciers in Northeast Greenland, which until recently were considered stable, and caused their rapid retreat. The main source of these waters is the westward recirculation of subducted Atlantic Water (AW) in Fram Strait, which has shown a warming of up to 1° C over the past few decades.</p><p>In this study, the connection between the subsurface warm Atlantic Intermediate Water (AIW) found on the wide continental shelf of Northeast Greenland and in the fjords, and AW within the West Spitsbergen Current (WSC) is investigated using historical hydrographic observations and high-resolution numerical simulations with the Finite-Element Sea-ice Ocean Model (FESOM). We find that AW from the WSC takes between 10 – 14 months to recirculate across Fram Strait and reach the shelf break where it moves southwards. The pronounced inter-annual variability in the WSC is preserved as the water recirculates. However, the variability of temperature and AIW layer thickness on the shelf at seasonal or inter-annual time scales is at best weakly controlled by the AW temperature in the WSC. There is no significant correlation between AIW and the WSC anywhere on the shelf, suggesting advection from the WSC alone does not control AIW signals. The role of wind-driven, episodic upwelling is then investigated as a driver of transport of AIW from Fram Strait onto the shelf (following an approach by Münchow et al., 2020) where it then may follow the deep trough system towards the glaciers.</p>

scholarly journals Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997–2010

2012 ◽  
Vol 69 (5) ◽  
pp. 852-863 ◽  
Author(s):  
Agnieszka Beszczynska-Möller ◽  
Eberhard Fahrbach ◽  
Ursula Schauer ◽  
Edmond Hansen
Keyword(s):  
Water Temperature ◽  
Arctic Ocean ◽  
Seasonal Variability ◽  
Atlantic Water ◽  
Volume Transport ◽  
The Arctic ◽  
Fram Strait ◽  
Mean Temperature ◽  
The Arctic Ocean

Abstract Beszczynska-Möller, A., Fahrbach, E., Schauer, U., and Hansen, E. 2012. Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997–2010. – ICES Journal of Marine Science, 69: 852–863. The variability in Atlantic water temperature and volume transport in the West Spitsbergen Current (WSC), based on measurements by an array of moorings in Fram Strait (78°50′N) over the period 1997–2010, is addressed. The long-term mean net volume transport in the current of 6.6 ± 0.4 Sv (directed northwards) delivered 3.0 ± 0.2 Sv of Atlantic water (AW) warmer than 2°C. The mean temperature of the AW inflow was 3.1 ± 0.1°C. On interannual time-scales, a nearly constant volume flux in the WSC core (long-term mean 1.8 ± 0.1 Sv northwards, including 1.3 ± 0.1 Sv of AW warmer than 2°C, and showing no seasonal variability) was accompanied by a highly variable transport of 2–6 Sv in the offshore branch (long-term mean of 5 ± 0.4 Sv, strong seasonal variability, and 1–2 Sv of warm AW). Two warm anomalies were found in the AW passing through Fram Strait in 1999–2000 and 2005–2007. For the period 1997–2010, there was a positive linear trend in the AW mean temperature of 0.06°C year−1, but no statistically significant trend was observed in the AW volume transport. A possible impact of warming on AW propagation in the Arctic Ocean and properties of the outflow to the North Atlantic are also discussed.

scholarly journals The role of interannual environmental variations in the geographic range of spawning and feeding concentrations of redfish Sebastes mentella in the Irminger Sea

2005 ◽  
Vol 62 (7) ◽  
pp. 1501-1510 ◽  
Author(s):  
Andrey P. Pedchenko
Keyword(s):  
Water Temperature ◽  
Central Area ◽  
Distribution Patterns ◽  
Atlantic Water ◽  
Western Slope ◽  
The North ◽  
Irminger Sea ◽  
Environmental Variations ◽  
Sebastes Mentella

Abstract The Irminger Sea is occupied by the most abundant population of the redfish, Sebastes mentella, in the North Atlantic. Results of Russian and international surveys of redfish in the Irminger Sea between 1982 and 2003 are summarized here. Interannual variations in redfish spatial distribution and oceanographic conditions are also analysed. Distribution patterns of spawning and feeding concentrations of redfish are established, and the role of oceanographic factors in the formation of concentrations and in the migrations of redfish are shown. The habitat of the mature redfish population in pelagic waters is confined within the Sub-polar cyclonic Gyre. Redfish spawning grounds extend along the western slope of the Reykjanes Ridge in the areas of intensive rise of intermediate waters. Seasonal variation in water temperature above the ridge slopes is one of the factors causing feeding redfish to migrate westwards, to the central area of the Sub-polar Gyre. Atlantic Water advection, intensified by the Irminger Sea, and water temperature increase in the upper 200-m layer in the second half of the 1990s produced a considerable shift of commercial concentrations of feeding redfish from their usual grounds westwards, to the NAFO Regulatory area.

scholarly journals Eddy‐driven recirculation of Atlantic Water in Fram Strait

2016 ◽  
Vol 43 (7) ◽  
pp. 3406-3414 ◽  
Author(s):  
Tore Hattermann ◽  
Pål Erik Isachsen ◽  
Wilken‐Jon Appen ◽  
Jon Albretsen ◽  
Arild Sundfjord
Keyword(s):  
Atlantic Water ◽  
Fram Strait

On the Role of Bottom Pressure Torques in Wind-Driven Gyres

2021 ◽  
Vol 51 (5) ◽  
pp. 1441-1464
Author(s):  
Andrew L. Stewart ◽  
James C. McWilliams ◽  
Aviv Solodoch
Keyword(s):  
Wind Stress ◽  
Bottom Friction ◽  
Bottom Pressure ◽  
Wind Stress Curl ◽  
Previous Theory ◽  
Model Experiments ◽  
Basin Scale ◽  
Vorticity Budget ◽  
Gyre Circulation

AbstractPrevious studies have concluded that the wind-input vorticity in ocean gyres is balanced by bottom pressure torques (BPT), when integrated over latitude bands. However, the BPT must vanish when integrated over any area enclosed by an isobath. This constraint raises ambiguities regarding the regions over which BPT should close the vorticity budget, and implies that BPT generated to balance a local wind stress curl necessitates the generation of a compensating, nonlocal BPT and thus nonlocal circulation. This study aims to clarify the role of BPT in wind-driven gyres using an idealized isopycnal model. Experiments performed with a single-signed wind stress curl in an enclosed, sloped basin reveal that BPT balances the winds only when integrated over latitude bands. Integrating over other, dynamically motivated definitions of the gyre, such as barotropic streamlines, yields a balance between wind stress curl and bottom frictional torques. This implies that bottom friction plays a nonnegligible role in structuring the gyre circulation. Nonlocal bottom pressure torques manifest in the form of along-slope pressure gradients associated with a weak basin-scale circulation, and are associated with a transition to a balance between wind stress and bottom friction around the coasts. Finally, a suite of perturbation experiments is used to investigate the dynamics of BPT. To predict the BPT, the authors extend a previous theory that describes propagation of surface pressure signals from the gyre interior toward the coast along planetary potential vorticity contours. This theory is shown to agree closely with the diagnosed contributions to the vorticity budget across the suite of model experiments.

The use of Cs and Sr isotopes as tracers in the Arctic Mediterranean Seas

1988 ◽  
Vol 325 (1583) ◽  
pp. 161-176 ◽  
Keyword(s):  
Deep Water ◽  
Thermohaline Circulation ◽  
Atlantic Water ◽  
The Arctic ◽  
Coastal Current ◽  
Intermediate Water ◽  
Sr Isotopes ◽  
Arctic Ice ◽  
Norwegian Coastal Current

The Arctic Mediterranean Seas constitute an oceanic region in which the thermohaline circulation has a strong advective component and deep ventilation processes are very active relative to other oceanic areas. Details of the nature of these circulation and ventilation processes have been revealed through use of Cs and Sr isotopes from bomb-fallout and nuclear-waste sources as ocean tracers. In both cases, their regional input is dominated by advective supply in the Norwegian Atlantic Current and Norwegian Coastal Current, respectively. The different temporal, spatial, and compositional input patterns of these tracers have been used to study different facets of the regional circulation. These input differences and some representative applications of the use of these tracers are reviewed. The data discussed derive from samples collected both from research vessels and from Arctic ice camps. The topics addressed include: ( a ) the role of Arctic Intermediate Water as source, supplying recent surface water to North Atlantic Deep Water via the Denmark Strait overflow; ( b ) deep convective mixing in the Greenland Sea; ( c ) circulation or recirculation of Atlantic water in the Arctic basins; and ( d ) the role of Arctic shelfwaters in the ventilation of intermediate and deep water in the Eurasian and Canadian basins.

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