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Abstract Changes in the Atlantic Meridional Overturning Circulation, which have the potential to drive societally-important climate impacts, have traditionally been linked to the strength of deep water formation in the subpolar North Atlantic. Yet there is neither clear observational evidence nor agreement among models about how changes in deep water formation influence overturning. Here, we use data from a trans-basin mooring array (OSNAP—Overturning in the Subpolar North Atlantic Program) to show that winter convection during 2014–2018 in the interior basin had minimal impact on density changes in the deep western boundary currents in the subpolar basins. Contrary to previous modeling studies, we find no discernable relationship between western boundary changes and subpolar overturning variability over the observational time scales. Our results require a reconsideration of the notion of deep western boundary changes representing overturning characteristics, with implications for constraining the source of overturning variability within and downstream of the subpolar region.
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Greenland Deep Western Boundary Current (GDWBC) Mooring Data 2020-2022 [Data set]
The Greenland Deep Western Boundary Current (GDWBC) mooring array is part of the Overturning in the Subpolar North Atlantic Project (OSNAP). The mooring array consists of four moorings instrumented with SeaBird 37 MicroCATs and Nortek Aquadopp Current Meters with the goal of 1) better defining the range of DWBC transport variability up to interannual time scales from continuous multi-year time series of velocity, temperature, and salinity, 2) identifying the causes of DWBC transport and water mass variability on multiple time scales, including connections to the dense overflows upstream, and 3) assessing DWBC continuity and connectivity around Cape Farewell and to the western boundary of the Subpolar North Atlantic. These moorings were deployed August 2020 to July 2022.
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- Award ID(s):
- 1948505
- PAR ID:
- 10567776
- Publisher / Repository:
- Woods Hole Oceanographic Institution
- Date Published:
- Format(s):
- Medium: X
- Institution:
- Woods Hole Oceanographic Institution
- Sponsoring Org:
- National Science Foundation
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Changes in the Atlantic Meridional Overturning Circulation, which have the potential to drive societally-important climate impacts, have traditionally been linked to the strength of deep water formation in the subpolar North Atlantic. Yet there is neither clear observational evidence nor agreement among models about how changes in deep water formation influence overturning. Here, we use data from a trans-basin mooring array (OSNAP—Overturning in the Subpolar North Atlantic Program) to show that winter convection during 2014–2018 in the interior basin had minimal impact on density changes in the deep western boundary currents in the subpolar basins. Contrary to previous modeling studies, we find no discernable relationship between western boundary changes and subpolar overturning variability over the observational time scales. Our results require a reconsideration of the notion of deep western boundary changes representing overturning characteristics, with implications for constraining the source of overturning variability within and downstream of the subpolar region.more » « less
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