FN Archimer Export Format PT J TI Stratification of surface waters during the last glacial millennial climatic events: a key factor in subsurface and deep-water mass dynamics BT AF WARY, M. EYNAUD, F. SABINE, M. ZARAGOSI, S. ROSSIGNOL, L. MALAIZE, B. PALIS, E. ZUMAQUE, J. CAULLE, C. PENAUD, A. MICHEL, E. CHARLIER, K. AS 1:1;2:1;3:1;4:1;5:1;6:1;7:1;8:1;9:1;10:2;11:3;12:1; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;12:; C1 Univ Bordeaux, EPOC, UMR 5805, F-33615 Pessac, France. UBO, IUEM, UMR 6538, F-29280 Plouzane, France. UVSQ, CNRS INSU, CEA, LSCE,UMR 8212, F-91198 Gif Sur Yvette, France. C2 UNIV BORDEAUX, FRANCE UBO, FRANCE UNIV VERSAILLES, FRANCE UM LGO IN DOAJ IF 3.638 TC 12 UR https://archimer.ifremer.fr/doc/00296/40767/39770.pdf https://archimer.ifremer.fr/doc/00296/40767/39771.pdf https://archimer.ifremer.fr/doc/00296/40767/48240.pdf LA English DT Article CR IMAGES V LEG 1-MD114 IMAGES V LEG 4-MD114 IMAGES V LEG 5 BO Marion Dufresne AB The last glacial period was punctuated by abrupt climatic events with extrema known as Heinrich and Dansgaard–Oeschger events. These millennial events have been the subject of many paleoreconstructions and model experiments in the past decades, but yet the hydrological processes involved remain elusive. In the present work, high-resolution analyses were conducted on the 12–42 ka BP section of core MD99-2281 retrieved southwest of the Faeroe Islands, and combined with analyses conducted in two previous studies (Zumaque et al., 2012; Caulle et al., 2013). Such a multiproxy approach, coupling micropaleontological, geochemical and sedimentological analyses, allows us to track surface, subsurface, and deep hydrological processes occurring during these rapid climatic changes. Records indicate that the coldest episodes of the studied period (Greenland stadials and Heinrich stadials) were characterized by a strong stratification of surface waters. This surface stratification seems to have played a key role in the dynamics of subsurface and deep-water masses. Indeed, periods of high surface stratification are marked by a coupling of subsurface and deep circulations which sharply weaken at the beginning of stadials, while surface conditions progressively deteriorate throughout these cold episodes; conversely, periods of decreasing surface stratification (Greenland interstadials) are characterized by a coupling of surface and deep hydrological processes, with progressively milder surface conditions and gradual intensification of the deep circulation, while the vigor of the subsurface northward Atlantic flow remains constantly high. Our results also reveal different and atypical hydrological signatures during Heinrich stadials (HSs): while HS1 and HS4 exhibit a "usual" scheme with reduced overturning circulation, a relatively active North Atlantic circulation seems to have prevailed during HS2, and HS3 seems to have experienced a re-intensification of this circulation during the middle of the event. Our findings thus bring valuable information to better understand hydrological processes occurring in a key area during the abrupt climatic shifts of the last glacial period. PY 2015 SO Climate Of The Past SN 1814-9324 PU Copernicus Gesellschaft Mbh VL 11 IS 11 UT 000365979200002 BP 1507 EP 1525 DI 10.5194/cp-11-1507-2015 ID 40767 ER EF