北半球の気候の高解像度記録は,最後の氷河間期にまで及ぶ
K K Andersen1, N Azuma, J-M Barnola
1Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark.
Nature
|September 10, 2004
まとめ
北グリーンランドの新しい氷芯は,最後の氷河間期間の安定した,より暖かい気候を明らかにしています. この記録は,最後の氷河期の始まりと,認識されていない急激な温暖化イベントの詳細を示しています.
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
- 気候科学 気候科学
背景:
- グリーンランドの中央部の氷芯は,北半球の気候再構築に不可欠です.
- これらのコアの古い部分には,氷の折りたたみによる時間的混乱があります.
- 最後の氷河期間の連続した,無干渉の気候記録が必要である.
研究 の 目的:
- 最後の氷河期間の北グリーンランドの氷芯から無干渉の気候記録を提示する.
- この期間の気温と気候の安定性を再構築する.
- 半球気候の動態と最後の氷河期の始まりを調査する.
主な方法:
- グリーンランド北部の深い氷の核の掘削と分析.
- 過去の温度を再構築するための酸素同位体分析.
- 氷の芯の断面の年代測定.
主要な成果:
- 12万3千年前まで遡る不変の気候記録です.
- 安定した気候条件で,最後の氷河期間の間,現在のより5°C暖かい温度.
- 約11万5千年前の,これまで認識されなかった突然の温暖化現象の証拠です.
- 北部と中部グリーンランドの記録の間に有意な温度差があり,北半球の氷の範囲は緯度温度グラデーションを調節することを示唆しています.
- 最後の氷河期の始まりを象徴するゆっくりとした気温下降.
- 急激な温暖化イベントに直接的な南極の対称性が欠如し,異なる南半球の気候相互作用を示しています.
結論:
- 最後の氷河期間の特徴は,グリーンランドの安定した,現在の気候より温暖な気候でした.
- 北半球の氷の広がりは,グリーンランドの緯度温度グラデーションに影響を与えました.
- 最後の氷河期が完全に形成される前に,認識されていない突然の温暖化が発生した.
- 半球間気候のシールソーメカニズムは,この特定の移行期間に支配的ではなかったかもしれません.
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