scholarly journals Circulation and transports in the Newfoundland Basin, western subpolar North Atlantic

2014 ◽  
Vol 119 (11) ◽  
pp. 7772-7793 ◽  
Author(s):  
Christian Mertens ◽  
Monika Rhein ◽  
Maren Walter ◽  
Claus W. Böning ◽  
Erik Behrens ◽  
...  
Keyword(s):  
North Atlantic ◽  
Newfoundland Basin

scholarly journals A multi-decadal meridional displacement of the Subpolar Front in the Newfoundland Basin

Ocean Science ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 91-102 ◽  
Author(s):  
I. Núñez-Riboni ◽  
M. Bersch ◽  
H. Haak ◽  
J. H. Jungclaus ◽  
K. Lohmann
Keyword(s):  
North Atlantic ◽  
General Circulation ◽  
Sea Water ◽  
Circulation Model ◽  
Heat Fluxes ◽  
Meridional Overturning Circulation ◽  
The North ◽  
Meridional Displacement ◽  
The North Atlantic ◽  
Newfoundland Basin

Abstract. Observations since the 1950s show a multi-decadal cycle of a meridional displacement of the Subpolar Front (SPF) in the Newfoundland Basin (NFB) in the North Atlantic. The SPF displacement is associated with corresponding variations in the path of the North Atlantic Current. We use the ocean general circulation model MPIOM with enhanced horizontal and vertical resolutions and forced with NCEP/NCAR reanalysis data to study the relation of the SPF displacement to atmospheric forcing, intensities of the subpolar gyre (SPG) and Meridional Overturning Circulation (MOC), and Labrador Sea Water (LSW) volume. The simulations indicate that the SPF displacement is associated with a circulation anomaly between the SPG and the subtropical gyre (STG), an inter-gyre gyre with a multi-decadal time scale. A sensitivity experiment indicates that both wind stress curl (WSC) and heat fluxes (which match LSW changes) contribute to the circulation anomalies in the frontal region and to the SPF displacement. An anticyclonic inter-gyre gyre is related to negative WSC and LSW anomalies and to a SPF north of its climatological position, indicating an expanding STG. A cyclonic inter-gyre gyre is related to positive WSC and LSW anomalies and a SPF south of its climatological position, indicating an expanding SPG. Therefore, the mean latitudinal position of the SPF in the NFB (a "SPF index") could be an indicator of the amount of LSW in the inter-gyre region. Spreading of LSW anomalies intensifies the MOC, suggesting our SPF index as predictor of the MOC intensity at multi-decadal time scales. The meridional displacement of the SPF has a pronounced influence on the meridional heat transport, both on its gyre and overturning components.

scholarly journals Sea-Surface Characteristics of the Newfoundland Basin of the Northwest Atlantic Ocean during the Last 145,000 Years: A Study Based on the Sedimentological and Paleontological Proxies

2021 ◽  
Vol 11 (8) ◽  
pp. 3343
Author(s):  
Harunur Rashid ◽  
Qian Qian Lu ◽  
Min Zeng ◽  
Yang Wang ◽  
Zhao Wu Zhang
Keyword(s):  
North Atlantic ◽  
Surface Characteristics ◽  
Water Masses ◽  
Sea Surface ◽  
Ecological Niches ◽  
Subpolar Gyre ◽  
North Atlantic Current ◽  
Northwest Atlantic ◽  
Newfoundland Basin ◽  
The Impact

Dramatic changes occur in the sea-surface characteristics (i.e., temperature and salinity) and freshwater input due to the interaction of cold and fresh Labrador Current and warm and salty North Atlantic Current (NAC) on the southeast Grand Banks. As a result, the biological productivity and seasonal stratification of the upper water masses are intensified. Such changes must have been more dramatic during the glacial times due to the penetration of the Polar and Arctic fronts and southward migration of the Gulf Stream/NAC. However, the extent to which such changes impacted the sea-surface characteristics in the Newfoundland Basin is poorly known. We report changes in the sea-surface characteristics using a piston core (Hu9007-08) collected from the Milne seamount during the last 145,000 years. Heinrich layers H1, H2, H4, and H5 and H11 within the MIS3 and at the penultimate deglaciation were identified by the ice-rafted detritus (IRD) and Neogloboquadrina pachyderma peaks and lighter oxygen isotopes. Rapid turnover by the foraminiferal species with distinct depth habitats and ecological niches in the mixed-layer and thermocline suggests an interplay between the polar and subpolar water masses during the Heinrich and non-Heinrich periods. Only two North Atlantic-wide cooling events, C24 and C21, in which the latter event linked to the minor IRD event during the marine isotope stage (MIS) 5 in Hu90-08, compared to the eight events in the eastern subpolar gyre (e.g., ODP site 984). Millennial-scale N. pachyderma variability in the western subpolar gyre appears to be absent in the eastern subpolar gyre during the MIS3 suggesting the occasional presence of salty and warm water by the NAC inflow, implying a different climate state between the western and eastern subpolar gyre. Although T. quinqueloba data are fragmentary, there are differences between the western and eastern subpolar gyre in addition to the differences within the western subpolar gyre during MIS5 that might imply a variable influence by the subpolar water. This finding suggests that the influence by the NAC outweighs the impact of cold and fresh polar water in the northern northwest Atlantic during the MIS5.

scholarly journals A multi-decadal meridional displacement of the Subpolar Front in the Newfoundland Basin

2011 ◽  
Vol 8 (1) ◽  
pp. 453-482 ◽  
Author(s):  
I. Núñez-Riboni ◽  
M. Bersch ◽  
H. Haak ◽  
J. H. Jungclaus
Keyword(s):  
North Atlantic ◽  
General Circulation ◽  
Sea Water ◽  
Circulation Model ◽  
Meridional Overturning Circulation ◽  
Western Boundary ◽  
The North ◽  
Meridional Displacement ◽  
The North Atlantic ◽  
Newfoundland Basin

Abstract. Observations since the 1950s show a multi-decadal cycle of a meridional displacement of the Subpolar Front (SPF) in the Newfoundland Basin (NFB) in the North Atlantic. The SPF displacement is associated with corresponding variations in the path of the North Atlantic Current. We use the ocean general circulation model MPIOM with enhanced horizontal and vertical resolutions and forced with NCEP/NCAR reanalysis data to study the relation of the SPF displacement to Labrador Sea Water (LSW) volume, atmospheric forcing and intensities of the Subpolar Gyre (SPG) and Meridional Overturning Circulation (MOC). The simulations indicate that the SPF displacement is associated with a circulation anomaly between the SPG and the subtropical gyre (STG), an inter-gyre gyre with a multi-decadal time scale. Contributions of wind stress curl (WSC) and LSW volume changes to the inter-gyre gyre are similar between 35 and 55° N (excluding the western boundary current). An anticyclonic inter-gyre gyre is related to negative WSC and LSW anomalies and to a SPF north of its climatological position, indicating an expanding STG. A cyclonic inter-gyre gyre is related to positive WSC and LSW anomalies and a SPF south of its climatological position, indicating an expanding SPG. Therefore, the mean latitudinal position of the SPF in the NFB could be an indicator of the amount of LSW in the inter-gyre region. Spreading of LSW anomalies intensifies the MOC, suggesting our SPF index as predictor of the MOC intensity at multi-decadal time scales. The meridional displacement of the SPF has a pronounced influence on the meridional heat transport, both on its gyre and overturning components.

The Atmospheric Response to North Atlantic SST Trends, 1870–2019

2020 ◽  
Author(s):  
Kristopher B. Karnauskas ◽  
Lei Zhang ◽  
Dillon J. Amaya
Keyword(s):  
North Atlantic ◽  
Atmospheric Response

The Currents of the North Atlantic

1892 ◽  
Vol 34 (872supp) ◽  
pp. 13940-13941
Author(s):  
Richard Beynon
Keyword(s):  
North Atlantic ◽  
The North ◽  
The North Atlantic
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