2007 Fiscal Year Final Research Report Summary
Study on abrupt climate and environment changes during glacial cycles by high time resolution anlalyzes of polar ice cores.
| Project/Area Number |
15101001
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| Research Category |
Grant-in-Aid for Scientific Research (S)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | National Institute of Polar Research |
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Principal Investigator |
FUJII Yoshiyuki National Institute of Polar Research, Director (20125214)
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| Co-Investigator(Kenkyū-buntansha) |
AOKI Shuji Tohoku University, Graduate School of Science and Faculty of Science, Professor (00183129)
YOSHIDA Naohiro Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Professor (60174942)
SHIBATA Yasuyuki National Institute of Polar Research, Division for Research and Education, Professor (20210099)
IIZUKA Yoshinori Hokkaido University, Institute of Low Temperature Science, Research Associate (40370043)
KAWAMURA Kenji National Institute of Polar Research, Division for Research and Education, Research Associate (90431478)
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| Project Period (FY) |
2003 – 2007
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| Keywords | Ice Core / Antarctica / Dome Fuji / Global Climate Change / Global Environmental Change / High time Resolution Analysis / Milankovitch Theory / Dust Flux |
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| Research Abstract |
(Objects) The two deep ice cores from Dome Fuji, Antarctica showed the occurrences of a number of abrupt climate and environment changes during the glacial cycles. Objectives of the research project are 1. to establish high time resolution analysis of the deep ice core from Dome Fuji, 2. to reconstruct detailed climatic and environment changes with yearly time scale, and 3. to study scenarios caused the abrupt changes in climate and environment
(Results) The high time resolution analyses of ice core in various climate stages (Holocene, LGM, interstadial and glacial stages) were done and the relationship between dust flux and non sea salt calcium ion was studied. The constitution of calcium mineral in dust was different depending on climate stages and it was suggested that the fluctuation was changed by relatively short cycle.
In order to investigate the roles of orbital and greenhouse-gas forcings on climate, one needs a paleoclimate chronology with an accuracy better than 〜ky (〜1/10 of
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precession cycle). Recently, Kawamura et at (2007, Nature) established such an Antarctic ice-core chronology for the past 360 ky through orbital tuning of O2/N2 ratio of trapped air in the Dome Fuji and Vostok ice cores with local summer insolation. The 02/N2 chronology permits comparisons between Antarctic climate, atmospheric greenhouse gas and insolation variations, thus providing a possible way to separate the respective contributions.
The 3035m of the ice core provides us with undisturbed climate record brick to 720, 000 years ago, the second longest ice core record after the Dome C ice core. The Dome Fuji 6180 record shows pervasive millennial-scale climate variability during the past seven glacial periods, as was reported for the Dome C 6D record. We find a close match between the Dome Fujiδ18O and the Dome δ1) records even on millennial scales, as well as on orbital time scales. This supports the integrity of both of the ice core records and suggests homogeneity of millennial-scale climate variability across East Antarctic Plateau over the past seven glacial periods. Mineral dust flux also shows millennial-scale variability, while sea salt flux doesn't. Less
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