HR: 1340h
AN: PP13B-1284    [Abstracts]
TI: Anti-phase variability of North Pacific ventilation and Atlantic overturning circulation during the last deglaciation
AU: * Uchida, M
EM: uchidama@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan
AU: * Uchida, M
EM: uchidama@nies.go.jp
AF: Woods Hole Oceanographic Institution, WHOI mail stop 4, Woods Hole, MA 02543, United States
AU: Ohkushi, K
EM: ohkushi@penguin.kobe-u.ac.jp
AF: Kobe University, 3-11 Tsurukabuto Nadaku, Kobe, 657-8501, Japan
AU: Kennett, J P
EM: kennett@geol.ucsb.edu
AF: University of California, Santa Barbara, Institute of Earth Sciences, Santa Barbara, CA 93106, United States
AU: Eglinton, T
EM: teglinton@whoi.edu
AF: Woods Hole Oceanographic Institution, WHOI mail stop 4, Woods Hole, MA 02543, United States
AU: Kimoto, K
EM: kimopy@jamstec.go.jp
AF: JAMSTEC, Natsushima, Yokosuka, 237-0061, Japan
AU: Shibata, Y
EM: yshibata@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan
AB: Modern North Pacific Intermediate Water (NPIW), the densest water formed in the North Pacific, is one of key water masses in the Pacific overturn circulation1. climate-driven fluctuations in the glacial NPIW (GNPIW) circulation held the clue to whether the millennial-scale global climate change during glacial times was initiated through ocean-atmosphere feedbacks or by changes in the Atlantic meridional overturning circulation(AMOC). Here we present high resolution records of ventilation change estimated from the 14C age difference between coexisting benthic and planktic foraminifera and sea surface temperatures and intermediate water temperature from two mid-depth cores in the northwestern Pacific near NPIW source region. During the last deglaciation, the GNPIW ventilation history was drastically changed with millennial time scales and also synchronous with the collapse and rapid resumption of the AMOC during cooling intervals of Heinrich event 1(H1). Ventilation rates were increased during cooling intervals of the H1 and the Younger Dryas. Conversely, during warming intervals of the preBorial and the Bølling-Ållerød (B/A), they were significantly decreased. Both warm periods coincide with maxima in surface ocean productivity reported along the western and eastern margins of the North Pacific2. On the other hand, alkenone surface water temperature in the deglacial period was coincidently changed with ventilation change and substantially dropped during Younger Dryas, synchronous with shutdown and reduction of the AMOC. These results suggest that the GNPIW ventilation was probably controlled by millennial fresh water cycle and the atmospheric teleconnections over the North Pacific driven by reorganization of oceans' overturn circulation.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4954 Sea surface temperature
DE: 4962 Thermohaline
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting