Knowledge (XXG)

Jean-Claude Duplessy

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climate change, as the future evolution of greenhouse gas concentrations can only be realistically simulated if the interactions between the biosphere and biogeochemical cycles are well understood, so that they can be taken into account in models simulating the behaviour of the "Earth" system. The last interglacial period of 120,000 years, often taken as an analogue of a significantly warmer climate than today, reflects major changes in global ocean temperature and circulation that have contributed to destabilizing the West Antarctic ice cap.
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role that the ocean can play in disrupting climate, as outlined in a book written for the general public entitled "When the ocean gets angry ". He is also the co-author of "Gros temps sur la planète ", "Paléoclimatologie : Tome 1, and Tome 2 "Paléoclimatologie : Tome 2, Emboiter les pièces du puzzle : comprendre et modéliser un système complexe ".
198:. This effort led the French teams to initiate, with their American and European colleagues, the International Joint Global Ocean Flux Study program to quantify carbon fluxes in the ocean and the role of plankton-produced particulate matter transfer in supplying the deep ocean environment with carbon, food and energy. 157:
of the Atlantic Ocean during the last glacial maximum with sufficient accuracy for major modelling groups to use this data to simulate global ocean circulation using general ocean circulation models. These results have provided the basis for understanding ocean circulation in glacial climates and the
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His mission was to coordinate the activities of some twenty scientists from the international community with the objective of showing how the study of ancient climates makes it possible to better understand the mechanisms that could come into play in a world whose climate is disrupted by greenhouse
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While developing this research and a group of marine paleoclimatology, he has endeavoured to bring to light in France the study of biogeochemical cycles within the surface envelopes of our planet. With the support of the CNRS, he launched the program to study the flow of matter in the ocean. This
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The deep waters of the world ocean are formed by convection and diving of dense surface waters during winter periods. To understand the causes of changes in deep ocean circulation, it was necessary to develop a method to reconstruct not only the temperature (which was already known), but also the
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Duplessy led numerous oceanographic campaigns and showed that variations in the isotopic composition of fossil foraminifera present in the sediments of the various oceans made it possible to reconstruct changes in the isotopic composition of the ocean and ocean circulation on a large scale, which
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reconstructions over geological time. These studies have thus made it possible to highlight phenomena as unexpected as the great variability of the carbon cycle in relation to changes in vegetation. These themes will become increasingly important in the coming years in the study of human-induced
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and living things. At the request of COFUSI (Comité français des unions scientifiques internationales), Duplessy chaired the French scientific committee of the International Geosphere-Biosphere Programme. He federated research on the physical, chemical and biological mechanisms that govern the
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in Chicago. The analysis of stable isotopes and natural radioactive elements makes it possible to approach the study of major biogeochemical cycles in an original way and to reconstruct changes in the Earth's climate and environment by applying current principles.
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to date marine sediments. With his collaborators, he was able to provide the first evidence of a ten-degree change in seawater temperature in times compatible with human life. These results were confirmed and further refined by the study of drilling in
701: 46:(Ulm), a physics graduate, is a geochemist. His work has contributed to a better understanding of how the ocean has functioned over the recent history of the Earth. He is a recognized pioneer in rebuilding ocean dynamics through the use of 114:, then by ocean circulation and finally, to a lesser extent, by gas exchanges between the ocean and the atmosphere. All these phenomena, which dominate the carbon cycle in the ocean, are now being taken into account to study the fate of 638: 194:
programme would bring together the actions of biologists, chemists and geochemists by highlighting the fundamental role of the coupling between biology and geochemistry, which led to the now recognized notion of
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shell oxygen in marine sediments. He was one of the first to see the importance of a high quality chronology for a reliable interpretation of measurements related to climate variations in the Earth's past.
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and air temperature at the time they were formed. He obtained the first reconstructions of air temperatures and climatic conditions in the south of France for the last millennia and for the previous
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salinity of surface waters in the past. Duplessy has developed a method based on fractionations that affect stable oxygen isotopes during the water cycle. This has allowed him to reconstruct the
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Duplessy J.C.,,et al., « Carbon-13 records of benthic foraminifera in the last interglacial ocean:  implications for the carbon cycle and the global deep water circulation »,
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Jean-Claude Duplessy was one of the lead authors of the "paleoclimatology" chapter of the report of the Intergovernmental Panel on Climate Change (IPCC), which was published in 2007.
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Jean-Claude Duplessy et Gilles Ramstein, Paléoclimatologie : Tome 2, Emboiter les pièces du puzzle : comprendre et modéliser un système complexe, Paris, 2 décembre 2013
102:.  His doctoral thesis work has focused on the geochemistry of stable carbon isotopes in the sea. He showed how the distribution of the stable heavy carbon isotope, 564:
Bard E., et al., « Retreat velocity of the North Atlantic Polar front during the last deglaciation determined by means of 14C accelerator mass spectrometry »,
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evolution of our environment. This research program initiated the study of the variability of the coupled geosphere-biosphere system, giving high priority to
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Labeyrie L.D., et al., « Changes in the oceanic  13C/12C ratio during the last 140,000 years : high latitude surface water records »,
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Duplessy J.C., La géochimie des isotopes stables du carbone dans la mer, Université de Paris VI, Thèse de doctorat ès Sciences Physiques, 21 juin 1972
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By the late 1980s, it had become clear that understanding living conditions on the Earth's surface required studying the couplings between the
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Duplessy J.C., et al., « Direct dating of the oxygen-isotope record of the last deglaciation by14C accelerator mass spectrometry »,
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Labeyrie L.D., et al., « Variations in the mode of formation and temperature of oceanic deep waters over the last 125,000 years »,
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Jean-Claude Duplessy et Gilles ramstein, Paléoclimatologie : Tome 1, Trouver, dater et interpréter les indices, Paris, 2 décembre 2013
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deep water disappears under glacial conditions, accompanied by a general slowdown in large-scale ocean circulation, the intensity of the
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Duplessy J.C., et al., « Response of global deep-water circulation to earth's climatic change 135,000-107,000 years ago. »,
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Chronology plays an essential role in understanding the evolution of climates and the links with astronomical theory initiated by Dr.
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Duplessy J.C., et al., « Differential isotopic fractionation in benthic foraminifera and paleotemperatures reassessed »,
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He began his research just as the foundations of isotopic geochemistry were beginning to be well established through the work of
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Duplessy J. C. et a, « Surface salinity reconstruction of the North Atlantic Ocean during the last glacial maximum »,
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Jean-Claude Duplessy initially focused on the concretions of the caves and demonstrated that they were good recorders of the
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gas and dust emissions. He was co-recipient, with his IPCC colleagues, of the 2007 Nobel Peace Prize in this capacity.
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Duplessy J.C., Let al., « Continental climatic variations between 130,000 and 90,000 years B.P »,
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He has been a member of the French Academy of Sciences since 2011 in the "Sciences of the Universe" section.
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thejointglobaloceanfluxstudy.4.1b8ae20512db692f2a680009040.html «  »The joint global ocean flux study
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Paléoclimatologie : Emboiter les pièces du puzzle : comprendre et modéliser un système complexe
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Duplessy J. C., Quand l'océan se fâche, Histoire naturelle du climat, Paris, Editions Odile Jacob, 1996
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He established the first reconstructions of the deep ocean circulation during the height of the last
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Duplessy Jean-Claude, Morel Pierre, Gros temps sur la planète, Paris, éditions Odile Jacob, 1990
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Duplessy turned to the ocean because of its role as a climate regulator and its major impact on
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ice. Today, rapid climatic variations are recognized as a major feature of climate change.
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Duplessy, J.C., et al., « The deep ocean during the last interglacial period »,
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He is a member of the European Academy of Sciences, Academia europaea since 1989
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Research directors of the French National Centre for Scientific Research
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Grand Prix Dolomieu of BRGM awarded by the Academy of Sciences in 2004.
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laboratory, one of the objectives of which is the fine measurement of
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and the heat flux transported by the Atlantic Ocean to the coasts of
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Winner of the Aimé Berthé Prize of the Academy of Sciences (1987)
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due to the development of new dating methods and the study of
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Dr Honoris Causa from the University of Kiel, Germany (2003).
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Paléoclimatologie. Trouver, dater, interpréter les indices
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Prestwich Prize of the French Geological Society 2004.
253:Grand Prix Louis D of the Institut de France 2004. 343:Palaeogeography, Palaeoclimatology, Palaeoecology 83:Recently, this type of study has been resumed in 42:Jean-Claude Duplessy, a former student of the 26:. He is Director of Research Emeritus at the 8: 247:of the Catholic University of Louvain (1997) 625:"Co-récipiendaire du Prix Nobel de la Paix" 177:. Duplessy launched the first accelerator 278:"Directeur de recherche émérite au CNRS" 269: 240:Milankovitch Medal of the EGS (1995). 7: 639:"Prix Nobel de la Paix pour le GIEC" 289: 287: 14: 446:"Quand l'Océan se fache-Babello" 707:École Normale Supérieure alumni 122:opened a new scientific field, 91:seems open to a great future. 1: 667:"Médaille Milutin Milankovic" 118:emitted by human activities. 22:, born in 1942, is a French 473:"Gros temps sur la planète" 728: 32:French Academy of Sciences 98:cycles, particularly the 169:in Louvain-La-Neuve and 44:Ecole Normale Supérieure 295:"Académie des sciences" 245:Georges Lemaître Prize 697:French climatologists 309:Quaternary Research 212:palaeo-environmental 133:and during the last 30:and a member of the 20:Jean-Claude Duplessy 653:"Academia europaea" 135:interglacial period 81:interglacial period 219:Honours and awards 124:paleo-oceanography 77:hydrological cycle 420:Oceanologica Acta 179:mass spectrometry 165:and developed by 16:French geochemist 719: 671: 670: 663: 657: 656: 649: 643: 642: 635: 629: 628: 621: 615: 613: 604: 598: 597: 590: 584: 579: 573: 571: 562: 556: 554: 545: 539: 538: 523: 517: 514: 508: 507: 492: 486: 483: 477: 476: 469: 463: 460: 454: 453: 442: 436: 433: 427: 425: 416: 410: 408: 399: 393: 391: 382: 376: 373: 367: 365: 356: 350: 348: 339: 333: 331: 322: 316: 314: 305: 299: 298: 291: 282: 281: 274: 175:Brown University 110:assimilation by 727: 726: 722: 721: 720: 718: 717: 716: 677: 676: 675: 674: 665: 664: 660: 651: 650: 646: 637: 636: 632: 623: 622: 618: 611: 605: 601: 592: 591: 587: 580: 576: 569: 563: 559: 552: 546: 542: 525: 524: 520: 515: 511: 494: 493: 489: 484: 480: 471: 470: 466: 461: 457: 444: 443: 439: 434: 430: 423: 417: 413: 406: 400: 396: 389: 383: 379: 374: 370: 363: 357: 353: 346: 340: 336: 329: 323: 319: 312: 306: 302: 293: 292: 285: 276: 275: 271: 266: 221: 196:biogeochemistry 69:Cesare Emiliani 61: 59:Scientific work 48:carbon isotopes 40: 17: 12: 11: 5: 725: 723: 715: 714: 709: 704: 699: 694: 689: 679: 678: 673: 672: 658: 644: 630: 616: 599: 585: 574: 557: 540: 518: 509: 487: 478: 464: 455: 437: 428: 411: 394: 377: 368: 351: 334: 317: 300: 283: 268: 267: 265: 262: 261: 260: 257: 254: 251: 248: 243:Winner of the 241: 238: 235: 232: 229: 225: 220: 217: 208:palaeoclimatic 147:Western Europe 139:North Atlantic 116:carbon dioxide 96:biogeochemical 60: 57: 52:foraminiferous 39: 36: 15: 13: 10: 9: 6: 4: 3: 2: 724: 713: 712:Living people 710: 708: 705: 703: 700: 698: 695: 693: 690: 688: 685: 684: 682: 668: 662: 659: 654: 648: 645: 640: 634: 631: 626: 620: 617: 610:, 2007, 316, 609: 603: 600: 595: 589: 586: 583: 578: 575: 568:, 1987, 328, 567: 561: 558: 551:, 1986, 320, 550: 544: 541: 536: 532: 528: 522: 519: 513: 510: 505: 501: 497: 491: 488: 482: 479: 474: 468: 465: 459: 456: 451: 447: 441: 438: 432: 429: 421: 415: 412: 405:, 1987, 327, 404: 398: 395: 388:, 1970, 168, 387: 381: 378: 372: 369: 362:, 1970, 226, 361: 355: 352: 344: 338: 335: 328:, 1985, 316, 327: 321: 318: 310: 304: 301: 296: 290: 288: 284: 279: 273: 270: 263: 258: 255: 252: 249: 246: 242: 239: 236: 233: 230: 226: 223: 222: 218: 216: 213: 209: 204: 199: 197: 191: 189: 184: 180: 176: 172: 168: 164: 159: 156: 150: 148: 144: 140: 136: 132: 127: 125: 119: 117: 113: 112:phytoplankton 109: 105: 101: 97: 92: 90: 86: 82: 78: 73: 70: 66: 58: 56: 53: 49: 45: 37: 35: 33: 29: 25: 21: 661: 647: 633: 619: 607: 602: 588: 577: 565: 560: 548: 543: 526: 521: 512: 495: 490: 481: 467: 458: 449: 440: 431: 422:, 1991, 14, 419: 414: 402: 397: 385: 380: 371: 359: 354: 345:, 1985, 50, 342: 337: 325: 320: 311:, 1984, 21, 308: 303: 272: 200: 192: 167:André Berger 163:Milankovitch 160: 151: 128: 120: 100:carbon cycle 93: 74: 62: 41: 19: 18: 692:Geochemists 687:1942 births 450:babelio.com 171:John Imbrie 143:Gulf Stream 108:chlorophyll 89:stalagmites 65:Harold Urey 681:Categories 535:275980741X 504:2759807401 264:References 24:geochemist 203:geosphere 188:Greenland 183:carbon-14 104:carbon-13 38:Biography 594:"COFUSI" 155:salinity 608:Science 572:791-794 555:350-352 426:311-324 409:477-482 392:250-251 386:Science 366:631-633 349:217-240 332:500-507 315:225-243 131:ice age 566:Nature 549:Nature 533:  502:  403:Nature 360:Nature 326:Nature 85:Europe 614:89-91 531:ASIN 500:ASIN 210:and 67:and 50:and 28:CNRS 173:at 683:: 612:p. 570:p. 553:p. 529:. 498:. 448:. 424:p. 407:p. 390:p. 364:p. 347:p. 330:p. 313:p. 286:^ 149:. 34:. 669:. 655:. 641:. 627:. 596:. 537:. 506:. 475:. 452:. 297:. 280:.

Index

geochemist
CNRS
French Academy of Sciences
Ecole Normale Supérieure
carbon isotopes
foraminiferous
Harold Urey
Cesare Emiliani
hydrological cycle
interglacial period
Europe
stalagmites
biogeochemical
carbon cycle
carbon-13
chlorophyll
phytoplankton
carbon dioxide
paleo-oceanography
ice age
interglacial period
North Atlantic
Gulf Stream
Western Europe
salinity
Milankovitch
André Berger
John Imbrie
Brown University
mass spectrometry

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