scholarly journals Joint effects of boundary currents and thermohaline intrusions on the warming of Atlantic water in the Canada Basin, 1993–2007

Author(s):  
Fiona A. McLaughlin ◽  
Eddy C. Carmack ◽  
William J. Williams ◽  
Sarah Zimmermann ◽  
Koji Shimada ◽  
...  
2020 ◽  
Vol 125 (8) ◽  
Author(s):  
Jianqiang Li ◽  
Robert S. Pickart ◽  
Peigen Lin ◽  
Frank Bahr ◽  
Kevin R. Arrigo ◽  
...  

ARCTIC ◽  
1974 ◽  
Vol 27 (4) ◽  
Author(s):  
J.L. Newton ◽  
L.K. Coachman

2018 ◽  
Vol 48 (2) ◽  
pp. 245-260 ◽  
Author(s):  
Hayley V. Dosser ◽  
Mary-Louise Timmermans

AbstractThe deep waters in the Canada Basin display a complex temperature and salinity structure, the evolution of which is poorly understood. The fundamental physical processes driving changes in these deep water masses are investigated using an inverse method based on tracer conservation combined with empirical orthogonal function analysis of repeat hydrographic measurements between 2003 and 2015. Changes in tracer fields in the deep Canada Basin are found to be dominated by along-isopycnal diffusion of water properties from the margins into the central basin, with advection by the large-scale Beaufort Gyre circulation as well as localized, vertical mixing playing important secondary roles. In the Barents Sea branch of the Atlantic Water layer, centered around 1200-m depth, diffusion is shown to be nearly twice as important as advection to lateral transport. Along-isopycnal diffusivity is estimated to be ~300–600 m2 s−1. Large-scale circulation patterns and lateral advective velocities associated with the anticyclonic Beaufort Gyre are inferred, with an average speed of 0.6 cm s−1. Below about 1500 m, along-isopycnal diffusivity is estimated to be ~200–400 m2 s−1.


2018 ◽  
Vol 48 (10) ◽  
pp. 2397-2418 ◽  
Author(s):  
Elizabeth C. Fine ◽  
Jennifer A. MacKinnon ◽  
Matthew H. Alford ◽  
John B. Mickett

AbstractAn intrahalocline eddy was observed on the Chukchi slope in September of 2015 using both towed CTD and microstructure temperature and shear sections. The core of the eddy was 6°C, significantly warmer than the surrounding −1°C water and far exceeding typical temperatures of warm-core Arctic eddies. Microstructure sections indicated that outside of the eddy the rate of dissipation of turbulent kinetic energy ε was quite low . However, at the edges of the eddy core, ε was elevated to . Three different processes were associated with elevated ε. Double-diffusive steps were found at the eddy’s top edge and were associated with an upward heat flux of 5 W m−2. At the bottom edge of the eddy, shear-driven mixing played a modest role, generating a heat flux of approximately 0.5 W m−2 downward. Along the sides of the eddy, density-compensated thermohaline intrusions transported heat laterally out of the eddy, with a horizontal heat flux of 2000 W m−2. Integrating these fluxes over an idealized approximation of the eddy’s shape, we estimate that the net heat transport due to thermohaline intrusions along the eddy flanks was 2 GW, while the double-diffusive flux above the eddy was 0.4 GW. Shear-driven mixing at the bottom of the eddy accounted for only 0.04 GW. If these processes continued indefinitely at the same rate, the estimated life-span would be 1–2 years. Such eddies may be an important mechanism for the transport of Pacific-origin heat, freshwater, and nutrients into the Canada Basin.


2014 ◽  
Vol 44 (9) ◽  
pp. 2353-2369 ◽  
Author(s):  
Wenli Zhong ◽  
Jinping Zhao

Abstract In 2004, a cold mode of Atlantic Water (AW) entered the western Canada basin, replacing the anomalously warm AW that resided in the basin since the 1990s. This slightly colder AW was denser than the 1990s warm mode; it gradually filled most of the western basin by 2009. The enhanced surface stress curl led to the spinup of the Beaufort Gyre and convergence of freshwater. The spinup also resulted in a deepening of the AW core at the center of the gyre and in shoaling of the AW core at the margins of the gyre. The density versus depth relationship revealed in this study shows that the depth of the maximum AW temperature was mainly controlled by the density structure before 2007; thus, it is the case when the denser water was deeper and the case when the lighter water was shallower around the basin. However, this relationship was reversed to become the case when the denser water was shallower and the case when the lighter water was deeper since 2008 inside the Beaufort Gyre. The combined effect of density and sea ice retreat that enhanced surface stress curl determined the depth of the AW inside the Beaufort Gyre since 2008. The deepening of the AW core and expanding of the area where the AW deepening occurred had a profound effect on the large-scale circulation in the Arctic Ocean.


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