TY - JOUR
T1 - State dependence of climatic instability over the past 720,000 years from Antarctic ice cores and climate modeling
AU - Dome Fuji Ice Core Project Members
AU - Kawamura, Kenji
AU - Abe-Ouchi, Ayako
AU - Motoyama, Hideaki
AU - Ageta, Yutaka
AU - Aoki, Shuji
AU - Azuma, Nobuhiko
AU - Fujii, Yoshiyuki
AU - Fujita, Koji
AU - Fujita, Shuji
AU - Fukui, Kotaro
AU - Furukawa, Teruo
AU - Furusaki, Atsushi
AU - Goto-Azuma, Kumiko
AU - Greve, Ralf
AU - Hirabayashi, Motohiro
AU - Hondoh, Takeo
AU - Hori, Akira
AU - Horikawa, Shinichiro
AU - Horiuchi, Kazuho
AU - Igarashi, Makoto
AU - Iizuka, Yoshinori
AU - Kameda, Takao
AU - Kanda, Hiroshi
AU - Kohno, Mika
AU - Kuramoto, Takayuki
AU - Matsushi, Yuki
AU - Miyahara, Morihiro
AU - Miyake, Takayuki
AU - Miyamoto, Atsushi
AU - Nagashima, Yasuo
AU - Nakayama, Yoshiki
AU - Nakazawa, Takakiyo
AU - Nakazawa, Fumio
AU - Nishio, Fumihiko
AU - Obinata, Ichio
AU - Ohgaito, Rumi
AU - Oka, Akira
AU - Okuno, Jun'ichi
AU - Okuyama, Junichi
AU - Oyabu, Ikumi
AU - Parrenin, Frédéric
AU - Pattyn, Frank
AU - Saito, Fuyuki
AU - Saito, Takashi
AU - Saito, Takeshi
AU - Sakurai, Toshimitsu
AU - Sasa, Kimikazu
AU - Seddik, Hakime
AU - Shibata, Yasuyuki
AU - Shinbori, Kunio
N1 - Publisher Copyright:
2017 © The Authors, some rights reserved.
PY - 2017/2
Y1 - 2017/2
N2 - Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720,000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instability with bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.
AB - Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate system and projections of its future change. We investigate the long-term characteristics of climatic variability using a new ice-core record from Dome Fuji, East Antarctica, combined with an existing long record from the Dome C ice core. Antarctic warming events over the past 720,000 years are most frequent when the Antarctic temperature is slightly below average on orbital time scales, equivalent to an intermediate climate during glacial periods, whereas interglacial and fully glaciated climates are unfavourable for a millennial-scale bipolar seesaw. Numerical experiments using a fully coupled atmosphere-ocean general circulation model with freshwater hosing in the northern North Atlantic showed that climate becomes most unstable in intermediate glacial conditions associated with large changes in sea ice and the Atlantic Meridional Overturning Circulation. Model sensitivity experiments suggest that the prerequisite for the most frequent climate instability with bipolar seesaw pattern during the late Pleistocene era is associated with reduced atmospheric CO2 concentration via global cooling and sea ice formation in the North Atlantic, in addition to extended Northern Hemisphere ice sheets.
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U2 - 10.1126/sciadv.1600446
DO - 10.1126/sciadv.1600446
M3 - Article
C2 - 28246631
AN - SCOPUS:85021841804
VL - 3
JO - Science advances
JF - Science advances
SN - 2375-2548
IS - 2
M1 - e1600446
ER -