プレオ・プレイストセンの氷の量,南極の気候,そして世界のデルタ18O記録
M E Raymo1, L E Lisiecki, Kerim H Nisancioglu
1Department of Earth Science, Boston University, 685 Commonwealth Avenue, Boston, MA 02215, USA. raymo@bu.edu
Science (New York, N.Y.)
|June 24, 2006
まとめ
両半球の氷の量の変化は,地元の夏の太陽照射によって制御された. 約100万年前,南極の海洋ベースの氷床への移行は,北半球と南半球の氷床を同期させた.
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 氷河学 氷河学とは
- 地球システム科学 地球システム科学
背景:
- 地球の半球における氷の体積の変動は,軌道力との複雑な相互作用を示している.
- 海洋デルタ18Oや海面などのグローバルに統合されたプロキシは,相内と相外の両方の軌道構成要素の影響を受けます.
研究 の 目的:
- 北半球と南半球のドライバを調査する 3~100万年前の氷の量変化.
- 古代気候記録における41,000年の傾斜周期の優位性を説明するために.
- プレイストセンの中期の移行と2万3千年の周期性の強化の原因を解明する.
主な方法:
- 海洋デルタ18Oと海面記録を含む古気候のプロキシデータの分析.
- 氷床のダイナミクスのモデリングと,日照圧への反応.
- 北半球と南半球の氷の量行動の比較.
主要な成果:
- 各半球における氷の量の変化は,主に地元の夏の太陽照射によって制御された.
- 半球間の相外プレセシオンサイクル (2万3000年) は,地球的なプロキシーでキャンセルにつながった.
- 南極の氷の質量のわずかな変化は,北半球のより大きな信号を相殺する可能性があります.
- プレイストセンの中期の移行は,海洋ベースの南極の氷床への移行を含み,南半球の行動を同期し,23,000年の周期性を強化しました.
結論:
- 全球的ではなく,地域的な夏の太陽照射が,研究期間中に半球氷の量変化を誘導した.
- 南極の海洋ベースの氷床への移行は,氷床のダイナミクスと古気候の周期性を根本的に変えました.
- 観測されたパターンは,古い記録における斜率強制の優位性と,移行後のより強いプレセーション信号の出現を説明します.
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