TY - JOUR T1 - Evidence for calcification depth change of Globorotalia truncatulinoides between deglaciation and Holocene in the Western Atlantic Ocean JF - Marine Micropaleontology Y1 - 2009 A1 - Cleroux, C. A1 - Lynch-Stieglitz, J. A1 - Schmidt, M. W. A1 - Cortijo, E. A1 - Duplessy, J. C. AB - Measurements of the delta O-18 in tests of planktonic and benthic foraminifera in the Florida Straits are used to reconstruct the properties of the water column through time over the last 12 ka (Lynch-Stieglitz et al., in press). The isotopic composition of the foraminifera largely reflects the vertical density gradient. We use this reconstruction and delta O-18 measurements on Globorotalia truncatulinoides in a nearby core to track the depth habitat of this species from the last deglaciation to 1.6 ka B.P. Around 9 ka, G. truncatulinoides was calcifying in much shallower water than during the late Holocene. The downward migration toward its modem habitat is a regional phenomenon over the western tropical Atlantic continental slope. The cause is still unclear but we hypothesize that the shallower calcification depth may be a response to the presence of glacial melt water or to circulation changes. This study points to the value of further study of the ecology, life cycle and calcification depth for G. truncatulinoides and other planktonic foraminifera that are used to reconstruct the history of the thermocline and upper water column structure. Published by Elsevier B.V. VL - 73 IS - 1-2 N1 - id: 1883; 514BR Times Cited:0 Cited References Count:33Y JO - Evidence for calcification depth change of Globorotalia truncatulinoides between deglaciation and Holocene in the Western Atlantic Ocean ER - TY - JOUR T1 - Florida Straits density structure and transport over the last 8,000 years JF - Paleoceanography Y1 - 2009 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Lund, D. C. VL - 24 IS - 3 N1 - id: 837; YY JO - Florida Straits density structure and transport over the last 8,000 years ER - TY - JOUR T1 - Deglacial variability in the surface return flow of the Atlantic meridional overturning circulation JF - Paleoceanography Y1 - 2008 A1 - Came, R. E. A1 - Oppo, D. W. A1 - Curry, W. B. A1 - Lynch-Stieglitz, J. AB - [1] Benthic foraminiferal Cd/Ca from a Florida Current sediment core documents the history of the northward penetration of southern source waters within the surface return flow of the Atlantic meridional overturning circulation (AMOC). Cd seawater estimates (Cd-W) indicate that intermediate-depth southern source waters crossed the equator and contributed to the Florida Current during the Bolling-Allerod warm period of the last deglaciation, consistent with evidence of only a modest AMOC reduction compared to today. The Cd-W estimates also provide the first paleoceanographic evidence of a reduction in the influence of intermediate-depth southern source waters within the Florida Current during the Younger Dryas, a deglacial cold event characterized by a weak North Atlantic AMOC. Our results reveal a close correspondence between the northward penetration of intermediate-depth southern source waters and the influence of North Atlantic Deep Water, suggesting a possible link between intermediate-depth southern source waters and the strength of the Atlantic AMOC. VL - 23 IS - 1 N1 - id: 838; 281YL Times Cited:4 Cited References Count:41; YY JO - Deglacial variability in the surface return flow of the Atlantic meridional overturning circulation ER - TY - JOUR T1 - Atlantic meridional overturning circulation during the Last Glacial Maximum JF - Science Y1 - 2007 A1 - Lynch-Stieglitz, J. A1 - Adkins, J. F. A1 - Curry, W. B. A1 - Dokken, T. A1 - Hall, I. R. A1 - Herguera, J. C. A1 - Hirschi, J. J. M. A1 - Ivanova, E. V. A1 - Kissel, C. A1 - Marchal, O. A1 - Marchitto, T. M. A1 - McCave, I. N. A1 - McManus, J. F. A1 - Mulitza, S. A1 - Ninnemann, U. A1 - Peeters, F. A1 - Yu, E. F. A1 - Zahn, R. AB - The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation. VL - 316 IS - 5821 N1 - id: 1897; ISI Document Delivery No.: 153XD Times Cited: 46 Cited Reference Count: 61 Cited References: ADKINS JF, 1997, NATURE, V390, P154 ADKINS JF, 1999, RECONSTRUCTING OCEAN, P103 ADKINS JF, 2003, EARTH PLANET SC LETT, V216, P109, DOI 10.1016/S0012-821X(03)00502-8 BACON MP, 1982, J GEOPHYS RES, V87, P2045 BICKERT T, 2004, S ATLANTIC LATE QUAT, P671 BOYLE EA, 1982, SCIENCE, V218, P784 BROECKER W, 1988, RADIOCARBON, V30, P261 CHASE Z, 2002, EARTH PLANET SC LETT, V204, P215 CLARK PU, 2002, NATURE, V415, P863 CONKRIGHT ME, 2002, WORLD OCEAN ATLAS 20 CURRY WB, 1982, QUATERNARY RES, V18, P218 CURRY WB, 2005, PALEOCEANOGRAPHY, V20, ARTN PA1017 DUPIESSY JC, 1980, NATURE, V286, P479 DUPLESSY JC, 1988, PALEOCEANOGRAPHY, V3, P343 DUPLESSY JC, 1989, RADIOCARBON, V31, P493 ELDERFIELD H, 2006, EARTH PLANET SC LETT, V250, P633, DOI 10.1016/j.epsl.2006.07.041 EMILIANI C, 1955, J GEOL, V63, P538 GANACHAUD A, 2000, NATURE, V408, P453 GEBBIE G, 2006, GEOCHEM GEOPHY GEOSY, V7, ARTN Q11N07 GHERARDI JM, 2005, EARTH PLANET SC LETT, V240, P710, DOI 10.1016/j.epsl.2005.09.061 HALL IR, 2006, GEOPHYS RES LETT, V33, ARTN L16616 HALL MM, 1982, DEEP-SEA RES, V29, P339 HEWITT CD, 2003, CLIM DYNAM, V20, P203, DOI 10.1007/s00382-002-0272-6 HIRSCHI JJM, 2006, GEOCHEM GEOPHY GEOSY, V7, ARTN Q10N04 HUYBERS P, 2007, J PHYS OCEANOGR, V37, P394, DOI 10.1175/JPO3018.1 KEIGWIN LD, 2004, PALEOCEANOGRAPHY, V19, ARTN PA4012 KISSEL C, 1999, EARTH PLANET SC LETT, V171, P489 KITOH A, 2001, GEOPHYS RES LETT, V28, P2221 KUCERA M, 2005, QUATERNARY SCI REV, V24, P951, DOI 10.1016/j.quascirev.2004.07.014 KUMAR N, 1993, NATURE, V362, P45 LEGRAND P, 1995, PALEOCEANOGRAPHY, V10, P1011 LEGRANDE AN, 2006, P NATL ACAD SCI USA, V103, P837 LYNCHSTIEGLITZ J, 1999, PALEOCEANOGRAPHY, V14, P360 LYNCHSTIEGLITZ J, 2001, GEOCHEM GEOPHY GEOSY, V2, DOI 10.1029/2001GC000208 LYNCHSTIEGLITZ J, 2003, TREATISE GEOCHEMISTR, V6, P433 LYNCHSTIEGLITZ J, 2006, GEOCHEM GEOPHY GEOSY, V7, ARTN Q10N03 MANABE S, 1988, J CLIMATOL, V1, P841 MANGINI A, 1998, NATURE, V392, P347 MARCHAL O, 2000, PALEOCEANOGRAPHY, V15, P625 MARCHITTO TM, 2000, PALEOCEANOGRAPHY, V15, P299 MARCHITTO TM, 2006, GEOCHEM GEOPHY GEOSY, V7, ARTN Q12003 MAROTZKE J, 1999, J GEOPHYS RES-OCEANS, V104, P29529 MATSUMOTO K, 1999, PALEOCEANOGRAPHY, V14, P149 MCCAVE IN, 2006, GEOCHEM GEOPHY GEOSY, V7, ARTN Q10N05 MCMANUS JF, 2004, NATURE, V428, P834, DOI 10.1038/nature02494 MIX AC, 2001, QUATERNARY SCI REV, V20, P627 OTTOBLIESNER BL, 2006, J CLIMATE, V19, P2526 PAUL A, 2003, PALEOCEANOGRAPHY, V18, ARTN 1058 PIOTROWSKI AM, 2005, SCIENCE, V307, P1933, DOI 10.1126/science.1104883 ROBINSON LF, 2005, SCIENCE, V310, P1469, DOI 10.1126/science.1114832 ROEMMICH D, 1985, DEEP-SEA RES, V32, P619 SARNTHEIN M, 1994, PALEOCEANOGRAPHY, V9, P209 SCHMITTNER A, 2005, GLOBAL BIOGEOCHEM CY, V19, ARTN GB3004 SHACKLETON NJ, 1988, NATURE, V335, P708 SHIN SI, 2003, CLIM DYNAM, V20, P127, DOI 10.1007/s00382-002-0260-x STOMMEL H, 1961, TELLUS, V13, P224 STREETER SS, 1979, SCIENCE, V203, P168 VELLINGA M, 2002, CLIMATIC CHANGE, V54, P251 WUNSCH C, 2003, QUATERNARY SCI REV, V22, P371 YU EF, 1996, NATURE, V379, P689 ZHANG R, 2005, J CLIMATE, V18, P1853 Lynch-Stieglitz, Jean Adkins, Jess F. Curry, William B. Dokken, Trond Hall, Ian R. Herguera, Juan Carlos Hirschi, Joel J. -M. Ivanova, Elena V. Kissel, Catherine Marchal, Olivier Marchitto, Thomas M. McCave, I. Nicholas McManus, Jerry F. Mulitza, Stefan Ninnemann, Ulysses Peeters, Frank Yu, Ein-Fen Zahn, Rainer Amer assoc advancement science Washington; YY JO - Atlantic meridional overturning circulation during the Last Glacial Maximum ER - TY - JOUR T1 - Surface currents in the western North Atlantic during the Last Glacial Maximum JF - Geochemistry Geophysics Geosystems Y1 - 2007 A1 - LeGrande, A. N. A1 - Lynch-Stieglitz, J. AB - [1] During the last ice age, the density gradient across the Florida Current was reduced, implying a reduction in the flow of the Gulf Stream through the Florida Straits. Here we investigate the possibility that a significant portion of this wind-driven western boundary flow bypassed the Florida Straits during glacial times due to either changes in bathymetry induced by the sea level drop or changes in wind patterns. Down core records of the oxygen isotope ratios of the planktonic foraminifer Globorotalia truncatulinoides are used to locate the density gradients and thus the locations of upper ocean currents in the western North Atlantic. We find that western boundary flow was largely confined within the Florida Straits during the Last Glacial Maximum as it is today. This finding supports the idea that the reduced density gradient across the Florida Current represents a reduction in the surface branch of the surface to deep meridional overturning circulation in the Atlantic rather than a reduction in the proportion of the wind-driven flow carried by the Florida Current. VL - 8 IS - 1 N1 - 131djTimes Cited:2Cited References Count:16 JO - Surface currents in the western North Atlantic during the Last Glacial Maximum ER - TY - JOUR T1 - Gulf Stream density structure and transport during the past millennium JF - Nature Y1 - 2006 A1 - Lund, D. C. A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. AB - The Gulf Stream transports approximately 31 Sv (1 Sv = 10(6) m(3) s(-1)) of water and 1.3 x 10(15) W of heat into the North Atlantic ocean. The possibility of abrupt changes in Gulf Stream heat transport is one of the key uncertainties in predictions of climate change for the coming centuries. Given the limited length of the instrumental record, our knowledge of Gulf Stream behaviour on long timescales must rely heavily on information from geologic archives. Here we use foraminifera from a suite of high-resolution sediment cores in the Florida Straits to show that the cross-current density gradient and vertical current shear of the Gulf Stream were systematically lower during the Little Ice Age (ad approximately 1200 to 1850). We also estimate that Little Ice Age volume transport was ten per cent weaker than today's. The timing of reduced flow is consistent with temperature minima in several palaeoclimate records, implying that diminished oceanic heat transport may have contributed to Little Ice Age cooling in the North Atlantic. The interval of low flow also coincides with anomalously high Gulf Stream surface salinity, suggesting a tight linkage between the Atlantic Ocean circulation and hydrologic cycle during the past millennium. VL - 444 IS - 7119 N1 - Lund, David CLynch-Stieglitz, JeanCurry, William BengResearch Support, U.S. Gov't, Non-P.H.S.England2006/12/01 09:00Nature. 2006 Nov 30;444(7119):601-4. JO - Gulf Stream density structure and transport during the past millennium ER - TY - JOUR T1 - Meridional overturning circulation in the South Atlantic at the last glacial maximum JF - Geochemistry Geophysics Geosystems Y1 - 2006 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Oppo, D. W. A1 - Ninneman, U. S. A1 - Charles, C. D. A1 - Munson, J. AB - The geostrophic shear associated with the meridional overturning circulation is reflected in the difference in density between the eastern and western margins of the ocean basin. Here we examine how the density difference across 30 degrees S in the upper 2 km of the Atlantic Ocean ( and thus the magnitude of the shear associated with the overturning circulation) has changed between the last glacial maximum and the present. We use oxygen isotope measurements on benthic foraminifera to reconstruct density. Today, the density in upper and intermediate waters along the eastern margin in the South Atlantic is greater than along the western margin, reflecting the vertical shear associated with the northward flow of surface and intermediate waters and the southward flowing North Atlantic Deep Waters below. The greater density along the eastern margin is reflected in the higher delta(18)O values for surface sediment benthic foraminifera than those found on the western margin for the upper 2 km. For the last glacial maximum the available data indicate that the eastern margin foraminifera had similar delta(18)O to those on the western margin between 1 and 2 km and that the gradient was reversed relative to today with the higher delta(18)O values in the western margin benthic foraminifera above 1 km. If this reversal in benthic foraminifera delta(18)O gradient reflects a reversal in seawater density gradient, these data are not consistent with a vigorous but shallower overturning cell in which surface waters entering the Atlantic basin are balanced by the southward export of Glacial North Atlantic Intermediate Water. VL - 7 N1 - 092siTimes Cited:17Cited References Count:46 JO - Meridional overturning circulation in the South Atlantic at the last glacial maximum ER - TY - JOUR T1 - Mid-Holocene El Nino-Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments JF - Geology Y1 - 2006 A1 - Koutavas, A. A1 - deMenocal, P. B. A1 - Olive, G. C. A1 - Lynch-Stieglitz, J. AB - Holocene reconstructions of the Ell Nino-Southern Oscillation (ENSO) provide valuable perspective on its recent evolution and can be important for assessing its future. Optimal assessment of past ENSO variability requires observations from its center of action in the eastern equatorial Pacific, but these are limited due to paucity of high-resolution paleoceanographic archives (e.g., corals). Here we use a new approach to quantify past ENSO variance based on the oxygen isotopic composition (delta O-18) of individual foraminifera (Globigerinoides ruber) from deep-sea sediments in the ENSO source region.. Individual G. ruber foraminifera behave as monthly recorders of sea-surface conditions, including ENSO extremes, circumventing the lack of annual resolution in the sediments. Intrapopulation delta O-18 distributions derived with this method from a core near the Galapagos Islands reveal mid-Holocene reductions in variance or 50%, requiring drastic attenuation of the ENSO amplitude. Furthermore, Mg/Ca thermometry indicates that mid-Holocene background conditions were accompanied by a stronger zonal temperature gradient that coincided with a northward-displaced Intertropical Convergence Zone (ITCZ). The results suggest that the position of the ITCZ is an important factor in the low-frequency modulation of ENSO and could influence its future evolution. VL - 34 IS - 12 N1 - 113wzTimes Cited:128Cited References Count:26 JO - Mid-Holocene El Nino-Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments ER - TY - JOUR T1 - Glacial-interglacial dynamics of the eastern equatorial Pacific cold tongue Intertropical Convergence Zone system reconstructed from oxygen isotope records JF - Paleoceanography Y1 - 2003 A1 - Koutavas, A. A1 - Lynch-Stieglitz, J. AB - We use planktonic oxygen isotope (delta(18)O) records spanning the last 30,000 years (kyr) to constrain the magnitude and spatial pattern of glacial cooling in the upwelling environment of the eastern equatorial Pacific (EEP). Fourteen new downcore delta(18)O records were obtained from surface-dwelling planktonic foraminifera Globigerinoides sacculifer and Globigerinoides ruber in eight cores from the upwelling tongue of the EEP. All sites have sedimentation rates exceeding 5 cm/kyr and, with one exception, lie above the modern depth of the foraminiferal lysocline. Sites directly underlying the cool band of upwelling immediately south of the equator record mean late Holocene (LH)-Last Glacial Maximum (LGM) delta(18)O amplitudes ranging between 1.0 and 1.3parts per thousand. We estimate that mean sea surface temperatures (SST) in this region during the LGM were on average 1.5 +/- 0.5degreesC lower than the LH. Larger delta(18)O amplitudes are observed in sites north of the equator, indicating a spatial pattern of reduced meridional SST gradient across the equator during the LGM. This result is supported by comparison of Mg/Ca SST reconstructions from two sites straddling the equator. We interpret the reduction of this gradient during the LGM as evidence for a less intense cold tongue-Intertropical Convergence Zone (ITCZ) frontal system, a more southerly position of the ITCZ, and weaker southeast equatorial trades in the EEP. VL - 18 IS - 4 N1 - 756nfTimes Cited:56Cited References Count:100 JO - Glacial-interglacial dynamics of the eastern equatorial Pacific cold tongue Intertropical Convergence Zone system reconstructed from oxygen isotope records ER - TY - JOUR T1 - Persistence of Gulf Stream separation during the Last Glacial Period: Implications for current separation theories JF - Journal of Geophysical Research-Oceans Y1 - 2003 A1 - Matsumoto, K. A1 - Lynch-Stieglitz, J. KW - cape-hatteras KW - deep-ocean KW - gulf stream separation KW - Last glacial maximum KW - marine sediment cores KW - north-atlantic KW - Ocean circulation KW - oxygen isotope composition KW - oxygen isotopic composition KW - past 21,000 years KW - planktonic foraminifera KW - planktonic-foraminifera KW - SARGASSO SEA KW - western boundary current KW - western boundary undercurrent KW - wind-driven AB - [1] We present stable oxygen isotope ratio (delta(18)O) measurements on deep-dwelling planktonic foraminifera from the western margin of the North Atlantic in order to reconstruct the latitude at which the Gulf Stream separated from the western boundary of the Atlantic Ocean in the past. The modern separation latitude can be reconstructed within one degree from delta(18)O measured on the fossil shells of deep-dwelling planktonic foraminifera Globorotalia truncatulinoides from the Holocene sediments representing the past 10,000 years of mild climate conditions similar to today. The separation latitude is captured in a sharp delta(18)O gradient, which reflects the prominent hydrographic change across the boundary between the warm waters south and east of the Gulf Stream and the cold Slope Water to the north. The latitudinal delta(18)O profile from approximately the Last Glacial Maximum shows that the Gulf Stream separated from the coast near Cape Hatteras at almost the same latitude as it does today. We assess our finding in light of existing Gulf Stream separation theories and conclude that one of the theories, the wind-induced separation mechanism, is not consistent with our paleoceanographic reconstruction. VL - 108 SN - 0148-0227 IS - C6 N1 - 690nvTimes Cited:14 Cited References Count:56 JO - J Geophys Res-Oceans ER - TY - JOUR T1 - Thirty thousand year record of climate from the Galapagos Islands and links with high latitudes JF - EOS Y1 - 2001 A1 - Koutavas, A. A1 - Lynch-Stieglitz, J. A1 - Sachs, J. P. A1 - Marchitto, T. M. AB - Fall Meeting Supplement F737 VL - 82 IS - 47 N1 - id: 255 JO - Thirty thousand year record of climate from the Galapagos Islands and links with high latitudes ER - TY - JOUR T1 - A geostrophic transport estimate for the Florida Current from the oxygen isotope composition of benthic foraminifera JF - Paleoceanography Y1 - 1999 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Slowey, N. AB - We present a new method for the quantitative reconstruction of upper ocean flows for during times in the past. For the warm (T>5 degrees C) surface ocean, density can be accurately reconstructed from calcite precipitated in equilibrium with seawater, as both of these properties increase with decreasing temperature and increasing salinity. Vertical density profiles can be reconstructed from the oxygen isotopic composition of benthic foraminifera. The net volume transport between two vertical density profiles can be calculated using the geostrophic method. Using benthic foraminifera from surface sediment samples from either side of the Florida Straits (Florida Keys and Little Bahama Bank), we reconstruct two vertical density profiles and calculate a volume transport of 32 Sv using this method. This agrees well with estimates from physical oceanographic methods of 30-32 Sv for the mean annual volume transport. We explore the sensitivity of this technique to various changes in the relationship between temperature and salinity as well as salinity and the oxygen isotopic composition of seawater. VL - 14 IS - 3 N1 - 198xcTimes Cited:81Cited References Count:45 JO - A geostrophic transport estimate for the Florida Current from the oxygen isotope composition of benthic foraminifera ER - TY - CHAP T1 - The overturning circulation of the glacial Atlantic: A view from the top T2 - Reconstructing Ocean History: A Window into the Future Y1 - 1999 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Slowey, N. A1 - Schmidt, G. A. ED - Abrantes, F. JF - Reconstructing Ocean History: A Window into the Future PB - Kluwer Academic/Plenum CY - New York N1 - id: 1364 ER - TY - CONF T1 - The overturning circulation of the glacial Atlantic: A view from the top T2 - Sixth International Conference on Paleoceanography Y1 - 1999 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Slowey, N. C. JF - Sixth International Conference on Paleoceanography N1 - id: 1337 ER - TY - JOUR T1 - Similar glacial and Holocene deep water circulation inferred from southeast Pacific benthic foraminiferal carbon isotope composition JF - Paleoceanography Y1 - 1999 A1 - Matsumoto, K. A1 - Lynch-Stieglitz, J. AB - We present Holocene and last glacial maximum (LGM) oxygen and carbon isotope measurements on Planulina wuellerstorfi in six southeast Pacific cores. Sedimentation rates are low in this part of the ocean, acid measurements were made on individual foraminiferal shells in order to identify the Holocene and glacial individuals on the basis of their extreme delta(18)O. The new delta(13)C data were combined with previous P. wuellerstorfi data for interpretation of global thermohaline circulation. Data from the Southern Ocean were examined closely for regional coherency and a few anomalous delta(13)C values suspected of having productivity overprint were removed. The resulting global delta(13)C distributions and gradients indicate that the deep water circulation was similar during the Holocene and LGM. This interpretation brings delta(13)C data to a better agreement with Cd/Ca data and marks a sharp contrast with a widely held view based on delta(13)C measurements that the glacial Southern Ocean was the terminus of the thermohaline circulation. The proposed presence of glacial North Atlantic Deep Water does not necessarily contradict the postulated presence of Glacial North Atlantic Intermediate Water. VL - 14 IS - 2 N1 - 179kdTimes Cited:61Cited References Count:90 JO - Similar glacial and Holocene deep water circulation inferred from southeast Pacific benthic foraminiferal carbon isotope composition ER - TY - JOUR T1 - Weaker Gulf Stream in the Florida straits during the last glacial maximum JF - Nature Y1 - 1999 A1 - Lynch-Stieglitz, J. A1 - Curry, W. B. A1 - Slowey, N. AB - As it passes through the Florida Straits, the Gulf Stream consists of two main components: the western boundary flow of the wind-driven subtropical gyre and the northward-flowing surface and intermediate waters which are part of the 'global conveyor belt' compensating for the deep water that is exported from the North Atlantic Ocean(1), The mean flow through the Straits is largely in geostrophic balance and is thus reflected in the contrast in seawater density across the Straits(2). Here we use oxygen-isotope ratios of benthic foraminifera which lived along the ocean margins on the boundaries of the Florida Current during the Last Glacial Maximum to determine the density structure in the water and thereby reconstruct transport through the Straits using the geostrophic method-a technique which has been used successfully for estimating present-day flow(3). Our data suggest that during the Last Glacial Maximum, the density contrast across the Florida Straits was reduced, with the geostrophic flow, referenced to the bottom of the channel, at only about two-thirds of the modern value. If the wind-driven western boundary flow was not lower during the Last Glacial Maximum than today, these results indicate a significantly weaker conveyor-belt component of the Gulf Stream compared to present-day values. Whereas previous studies based on tracers suggested that deep waters of North Atlantic origin were not widespread during glacial times, indicating either a relatively weak or a shallow overturning cell, our results provide evidence that the overturning cell was indeed weaker during glacial times. VL - 402 IS - 6762 N1 - 264pcTimes Cited:122Cited References Count:31 JO - Weaker Gulf Stream in the Florida straits during the last glacial maximum ER - TY - JOUR T1 - A Younger Dryas Temperature Reversal in the Eastern Equatorial Pacific, EOS, Transactions JF - AGU, 1999 Fall Meeting Y1 - 1999 A1 - Koutavas, A. A1 - Lynch-Stieglitz, J. VL - 80 N1 - id: 167; 46 JO - A Younger Dryas Temperature Reversal in the Eastern Equatorial Pacific, EOS, Transactions ER -