[M-IS05] 南大洋・南極氷床が駆動する全球気候変動

[MIS05-P09] Climatic and atmospheric changes over the last three Terminations from O₂/N₂,d¹⁸O_atm and CH₄ records of the Dome Fuji ice core, Antarctica

*大藪 幾美¹、川村 賢二^1,2,3、北村 享太郎¹、Orsi Anais⁴、Parrenin Fredric⁵、Buizert Christo⁶ (1.情報・システム研究機構　国立極地研究所、2.総合研究大学院大学、3.海洋研究開発機構、4.フランス気候環境科学研究所、5.フランス地球環境科学研究所、6.オレゴン州立大学)

キーワード：アイスコア、退氷期、南極

Understanding the mechanisms of glacial terminations and associated global climatic changes is an important area of paleoclimatic research, because the terminations involve various interactions between the atmosphere, ocean, ice, and solid earth over multiple timescales. However, the climatic variations for the older terminations than the last one are relatively poorly reconstructed because of the limitations of available paleoclimatic proxies, time resolution, and chronological controls. Here, we revise the Dome Fuji chronology using newly measured O₂/N₂ ratio (a proxy of local summer insolation) combined with densification modeling and ice flow modeling, and discuss the timing of climatic and atmospheric variations including abrupt changes for Termination I, II and III, based on the records of CH₄ concentrations and δ¹⁸O of O₂ in the Dome Fuji ice core.