@article {27,
	title = {Radiocarbon evidence for a possible abyssal front near 3.1 km in the glacial equatorial Pacific Ocean},
	journal = {Earth and Planetary Science Letters},
	volume = {425},
	year = {2015},
	pages = {93-104},
	abstract = {We investigate the radiocarbon ventilation age in deep equatorial Pacific sediment cores using the difference in conventional 14C age between coexisting benthic and planktonic foraminifera, and integrate those results with similar data from around the North Pacific Ocean in a reconstruction for the last glaciation (15 to 25 conventional 14C ka). Most new data from both the Equatorial Pacific and the Emperor Seamounts in the northwestern Pacific come from maxima in abundance of benthic taxa because this strategy reduces the effect of bioturbation. Although there remains considerable scatter in the ventilation age estimates, on average, ventilation ages in the Equatorial Pacific were significantly greater below 3.2 km ( \~{} 3080 {\textpm} 1125 yrs , n = 15 ) than in the depth interval 1.9 to 3.0 km ( \~{} 1610 {\textpm} 250 yrs , n = 12 ). When compared to the average modern seawater Δ C 14 profile for the North Pacific, the Equatorial Pacific glacial data suggest an abyssal front located somewhere between 3.0 and 3.2 km modern water depth. Above that depth, the data may indicate slightly better ventilation than today, and below that depth, glacial Equatorial Pacific data appear to be as old as last glacial maximum (LGM) deep water ages reported for the deep southern Atlantic. This suggests that a glacial reservoir of aged waters extended throughout the circumpolar Southern Ocean and into the Equatorial Pacific. Renewed ventilation of such a large volume of aged (and, by corollary, carbon-rich) water would help to account for the rise in atmospheric pCO2 and the fall in Δ C 14 as the glaciation drew to a close.},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2015.05.025},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X15003210},
	author = {Keigwin, L. D. and Lehman, S. J.}
}
@article {693,
	title = {Marine radiocarbon evidence for the mechanism of deglacial atmospheric CO2 rise},
	journal = {Science},
	volume = {316},
	year = {2007},
	note = {Marchitto, Thomas MLehman, Scott JOrtiz, Joseph DFluckiger, Jacquelinevan Geen, AlexanderengResearch Support, U.S. Gov{\textquoteright}t, Non-P.H.S.2007/05/15 09:00Science. 2007 Jun 8;316(5830):1456-9. Epub 2007 May 10.},
	month = {Jun 08},
	pages = {1456-9},
	abstract = {We reconstructed the radiocarbon activity of intermediate waters in the eastern North Pacific over the past 38,000 years. Radiocarbon activity paralleled that of the atmosphere, except during deglaciation, when intermediate-water values fell by more than 300 per mil. Such a large decrease requires a deglacial injection of very old waters from a deep-ocean carbon reservoir that was previously well isolated from the atmosphere. The timing of intermediate-water radiocarbon depletion closely matches that of atmospheric carbon dioxide rise and effectively traces the redistribution of carbon from the deep ocean to the atmosphere during deglaciation.},
	issn = {0036-8075 (Linking)},
	doi = {10.1126/science.1138679},
	author = {Marchitto, T. M. and Lehman, S. J. and Ortiz, J. D. and Fluckiger, J. and van Geen, A.}
}
@conference {1680,
	title = {Marine 14C calibration and activity record for the past 50,000 years from the Cariaco Basin, Abstract},
	booktitle = {Eos Trans AGU 87, Fall Meeting Supple.},
	year = {2006},
	note = {id: 1076},
	month = {2006},
	address = {San Francisco, CA},
	author = {Hughen, K. A. and Southon, J. and Lehman, S. J. and Jenkins, W.}
}
@article {1944,
	title = {Marine-derived 14C calibration and activity record for the past 50,000 years updated from the Cariaco Basin},
	journal = {Quaternary Science Reviews},
	volume = {25},
	year = {2006},
	note = {id: 553},
	month = {2006},
	pages = {3216-3227},
	author = {Hughen, K. A. and Southon, J. A. and Lehman, S. J. and Bertrand, C. J. H. and Turnbull, J.}
}
@conference {1816,
	title = {An updated 14C calibration and activity record for the past 50,000 years from marine Cariaco Basin, Abstract},
	booktitle = {19th International Radiocarbon Conference},
	year = {2006},
	note = {id: 559},
	month = {2006},
	address = {Oxford, UK},
	author = {Hughen, K. A. and Southon, J. A. and Lehman, S. J. and Bertrand, C. J. H. and Turnbull, J.}
}
@conference {1544,
	title = {14C activity and global carbon cycle changes over the past 50,000 years},
	booktitle = {Abstracts, 18th International Radiocarbon Conf.},
	year = {2003},
	note = {id: 1079},
	month = {2003},
	address = {Wellington, NZ},
	author = {Hughen, K. A. and Lehman, S. J. and Southon, J. and Overpeck, J. T. and Marchal, O. and Herring, C. and Turnbull, J.}
}
@article {2069,
	title = {Deep sea records from the southeast Labrador Ocean circulation changes and ice-rafting events during hte last 160,000 years},
	journal = {Paleoceanography},
	volume = {18},
	year = {2003},
	note = {id: 989},
	month = {2003},
	author = {Rasmussen, T. L. and Oppo, D. W. and Thompson, E. and Lehman, S. J.}
}
@conference {1763,
	title = {Radiocarbon calibration and abruptchanges in atmospheric 14Cconcentration during Marine Isotope Stage 3},
	booktitle = {American Geophysical Union},
	year = {2000},
	note = {id: 327},
	month = {2000},
	address = {San Francisco, CA},
	author = {Hughen, K. A. and Southon, J. and Lehman, S. J. and Peterson, L. C. and Overpeck, J. T.}
}
@article {2347,
	title = {North Atlantic Deep Water variability during stage 3},
	journal = {Eos, Transactions, American Geophysical Union},
	volume = {76},
	year = {1995},
	note = {id: 58},
	month = {1995},
	pages = {171-172},
	author = {Oppo, D. W. and Lehman, S. J. and Curry, J. and Lynch, Stieglitz and Fairbanks, R. G.}
}
@article {784,
	title = {Suborbital Timescale Variability of North-Atlantic Deep-Water during the Past 200,000 Years},
	journal = {Paleoceanography},
	volume = {10},
	year = {1995},
	note = {Rx409Times Cited:145Cited References Count:39},
	month = {Oct},
	pages = {901-910},
	abstract = {We generated similar to 200-kyr-long proxy records of surface and deepwater variability from a subpolar North Atlantic core (V29-202), enabling us to assess the linkage between surface and deepwater changes on suborbital timescales. In particular, we used a benthic delta(13)C record to evaluate the deep water response to Dansgaard-Oeschger temperature oscillations and to Heinrich events, times of massive iceberg delivery to the North Atlantic. We found that the reduction of North Atlantic Deep Water (NADW) production was generally associated with cold or dropping sea surface temperatures (SSTs) as indicated by planktonic foraminiferal assemblages. The NADW contribution to the site did not drop appreciably during Heinrich events H4 through H2, probably because these events followed intervals of prolonged surface cooling already characterized by low rates of NADW production. By contrast NADW reduction appears to have been synchronous with H5. SST rise associated with both Dansgaard-Oeschger oscillations and Heinrich events was usually accompanied by increasing NADW strength. In a few cases the NADW recovery appeared to lag the SST rise; however, the apparent delay is most likely an artefact of the sedimentary record (low concentrations of benthic foraminifera). As a result of low benthic foraminiferal abundances during stage 6, the stage 6 benthic foraminiferal delta(13)C record is of lower resolution than the younger part of the record. The stage 6 proxy records for surface hydrography nevertheless reveal millennial-scale oscillations similar to those seen in stage 3. The available delta(13)C data suggest that NADW weakened in association with the cold portions of stage 6 SST oscillations. We also sought to confirm a recent study which concluded that there was little NADW variability during the peak of the last interglaciation, marine oxygen isotope substage 5e (Eemian). Isotope stage 5 was marked by a trend of increasing benthic delta(13)C in V29-202. Rising delta(13)C through isotope stage 5 is also seen in tropical surface water records and at some deep Atlantic sites and may reflect the common derivation of these water masses. Variations of greater than or equal to 0.5 parts per thousand superimposed on this rising delta(13)C trend within substage 5e in V29-202 are so far not evident in tropical feed waters and may therefore indicate that NADW production was weaker during the late than mid-Eemian.},
	issn = {0883-8305},
	doi = {10.1029/95pa02089},
	author = {Oppo, D. W. and Lehman, S. J.}
}
@article {2345,
	title = {Two-step deglaciation of the southeastern Barents Sea},
	journal = {Geology},
	volume = {23},
	year = {1995},
	note = {id: 62},
	month = {1995},
	pages = {567-571},
	author = {Polyak, L. and Lehman, S. J. and Gataulin, V. and Jull, A. J. T.}
}
@article {755,
	title = {The Role of the Deep-Ocean in North-Atlantic Climate-Change between 70-Kyr and 130-Kyr Ago},
	journal = {Nature},
	volume = {371},
	year = {1994},
	note = {Ph254Times Cited:159Cited References Count:32},
	month = {Sep 22},
	pages = {323-326},
	abstract = {THE suggestion(1) that changes in North Atlantic Deep Water (NADW) production are linked through surface heat flux to the atmospheric temperature over Greenland is supported by earlier indications(2,3) that NADW production decreased during glacial times, and by the subsequent finding(4-6) that it declined during the Younger Dryas cool period at the end of the last glaciation. Changes in North Atlantic surface temperatures have been found? to mirror high-frequency temperature changes recorded in Greenland ice cores over the past 80 kyr, but the connection to abyssal circulation has yet to be established, except for one or two isolated oscillations(8,9). Here we present carbon and oxygen isotope analyses of benthic foraminifera in a high-resolution North Atlantic deepsea sediment core for the period 70-130 kyr ago. These data allow us to reconstruct the history of NADW production, which shows a close correlation with Greenland climate variability for much of this time interval, suggesting that the climate influence of NADW variability was widespread. We see no evidence, however, for changes in NADW production during substage 5e (the Eemian interglacial period), in contrast with recent ice-core data(10) which suggest severe climate instability in Greenland during this time period. Our results may support suggestions, based on data from a second ice core, that this apparent instability is am artefact caused by ice flow(11). Alternatively, the Eemian climate instability may have had a different origin from the subsequent climate events.},
	issn = {0028-0836},
	doi = {10.1038/371323a0},
	author = {Keigwin, L. D. and Curry, W. B. and Lehman, S. J. and Johnsen, S.}
}
