@article {2812,
	title = {Sortable silt records of intermediate-depth circulation and sedimentation in the Southwest Labrador Sea since the Last Glacial Maximum},
	journal = {Quaternary Science Reviews},
	volume = {206},
	year = {2019},
	month = {Jan-02-2019},
	pages = {99 - 110},
	abstract = {The Labrador Sea is a vital region for the Atlantic Meridional Overturning Circulation (AMOC), where overflow waters from the Nordic Seas mix with locally produced Labrador Sea Water (LSW), before exiting to the interior of the Atlantic Ocean. The dynamical sedimentary proxy of mean sortable silt size () can give information on past changes in deep water circulation speed and the strength of AMOC. We have produced records from two core sites at depths between 1500 and 2000 m on the continental slope east of Newfoundland, to reconstruct changes in intermediate depth water circulation speed, including Glacial North Atlantic Intermediate Water and Labrador Sea Water over the past 22,000 years. Increases in appear to coincide with much of the deglaciation as well as the mid-late Holocene. End-member modeling suggests that ice-rafted debris (IRD) is an important factor in interpreting during the deglaciation. We find that a robust increase in is likely unrelated to IRD during the past 5 ka, and probably reflects increased flow at intermediate depths due to local production of LSW strengthening as Nordic Seas overflows weakened at this depth. Our results highlight both the complications of producing records in IRD-rich, slope environments and the promise that this proxy nevertheless has for reconstructing dynamical changes in deep ocean currents.},
	keywords = {Holocene, labrador sea, paleoceanography, Sedimentology-marine cores},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2018.12.028},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379118306449},
	author = {Hoffmann, Sharon S. and Dalsing, Risa E. and Murphy, Sarah C.}
}
@article {2811,
	title = {Evidence for Stable Holocene Basin-Scale Overturning Circulation Despite Variable Currents Along the Deep Western Boundary of the North Atlantic Ocean},
	journal = {Geophysical Research Letters},
	volume = {45},
	year = {2018},
	month = {Apr-12-2020},
	abstract = {While substantial changes in thermohaline circulation related to deglacial climate variability are well established, the role of this circulation in Holocene climate variability remains uncertain. Here we use two dynamical proxies, 231Pa/230Th ratios and mean sortable silt size ( urn:x-wiley:00948276:media:grl58406:grl58406-math-0001), to reconstruct Holocene bottom water circulation at the intermediate-depth Carolina Slope. We find no substantial change in deep current speed or 231Pa export at this site during the Holocene, suggesting consistent 231Pa export via the Deep Western Boundary Current. urn:x-wiley:00948276:media:grl58406:grl58406-math-0002 shows increasing millennial-scale variability in the middle-late Holocene, which may reflect Labrador Sea Water contribution to current speed. We conclude that deepwater export from the North Atlantic has remained remarkably stable during the Holocene, decoupled from changing rates of specific water masses, while production of these water masses varied at millennial to centennial time scales. The persistence of the large-scale overturning may reflect the ocean{\textquoteright}s stabilizing influence on Holocene climate.},
	keywords = {chemical tracers, interglacial, Radioactivity and radioisotopes, sedimentation (1861), thermohaline},
	issn = {0094-8276},
	doi = {10.1029/2018GL080187},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080187},
	author = {Hoffmann, Sharon S. and McManus, Jerry F. and Swank, Emerson}
}
@article {2545,
	title = {Persistent export of 231Pa from the deep central Arctic Ocean over the past 35,000 years},
	journal = {Nature},
	volume = {497},
	year = {2013},
	month = {May-05-2015},
	pages = {603 - 606},
	abstract = {The Arctic Ocean has an important role in Earth{\textquoteright}s climate, both through surface processes1 such as sea-ice formation and transport, and through the production and export of waters at depth that contribute to the global thermohaline circulation2, 3. Deciphering the deep Arctic Ocean{\textquoteright}s palaeo-oceanographic history is a crucial part of understanding its role in climatic change. Here we show that sedimentary ratios of the radionuclides thorium-230 (230Th) and protactinium-231 (231Pa), which are produced in sea water and removed by particle scavenging on timescales of decades to centuries, respectively4, record consistent evidence for the export of 231Pa from the deep Arctic and may indicate continuous deep-water exchange between the Arctic and Atlantic oceans throughout the past 35,000 years. Seven well-dated box-core records provide a comprehensive overview of 231Pa and 230Th burial in Arctic sediments during glacial, deglacial and interglacial conditions. Sedimentary 231Pa/230Th ratios decrease nearly linearly with increasing water depth above the core sites, indicating efficient particle scavenging in the upper water column and greater influence of removal by lateral transport at depth. Although the measured 230Th burial is in balance with its production in Arctic sea water, integrated depth profiles for all time intervals reveal a deficit in 231Pa burial that can be balanced only by lateral export in the water column. Because no enhanced sink for 231Pa has yet been found in the Arctic, our records suggest that deep-water exchange through the Fram strait may export 231Pa. Such export may have continued for the past 35,000 years, suggesting a century-scale replacement time for deep waters in the Arctic Ocean since the most recent glaciation and a persistent contribution of Arctic waters to the global ocean circulation.},
	keywords = {Marine chemistry, Palaeoceanography, Palaeoclimate},
	issn = {0028-0836},
	doi = {10.1038/nature12145},
	url = {http://www.nature.com/doifinder/10.1038/nature12145},
	author = {Hoffmann, Sharon S. and McManus, Jerry F. and Curry, William B. and Brown-Leger, L. Susan}
}
