淡水放出と海洋循環を通じて,氷河気候の強い半球結合
R Knutti1, J Flückiger, T F Stocker
1Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. knutti@climate.unibe.ch
Nature
|August 20, 2004
まとめ
最後の氷河期における気候の変動は,海洋循環の変化によって引き起こされた. 北大西洋への淡水排出は,南大洋の温度に直接影響を及ぼし,改訂された双極性揺らぎの気候モデルを支持します.
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
- 海洋学 海洋学 海洋学
- 気候モデリング
背景:
- 最後の氷河期における千年規模の気候変動は,北半球の急激な温暖化と南極の温度変化の遅さを示した.
- 海洋熱ハリン循環 (THC) の障害は,この気候の変動の原因として広く受け入れられています.
- 世界の海水位も,これらの気候変化に伴って変化した.
研究 の 目的:
- 北大西洋の淡水排出が南洋の温度に及ぼす直接的な影響を調査する.
- 双極性気候の動態を駆動するメカニズムと,海面の変化との関係を解明する.
- 拡張され,定量的な双極性揺らぎの概念を提示する.
主な方法:
- 海洋・大気・海氷のモデルを用いた.
- 北大西洋への淡水排出をシミュレートした.
- 海洋熱伝送と密度グラデーションを分析した.
主要な成果:
- 北大西洋への淡水排出は,THCの減少と併せて,南大洋の温度に直接影響を及ぼします.
- 異常な南向きの海洋熱輸送は,亜熱帯北大西洋のゾナ密度の傾斜から発生します.
- このモデルは,グリーンランドと南極の気温変化のタイミングと振幅,南極の気温と海面の類似性をうまく説明しています.
結論:
- この研究は,北大西洋と南大洋の気候の動態を結びつける二極性揺らぎメカニズムのための定量的な枠組みを提供します.
- これは,北大西洋の淡水パルスが,世界の気候パターンに直接的に影響していることを示しています.
- この発見は,海洋循環,極地の気温,氷河期間の海面変動の複雑な相互作用についての洞察を提供しており,海洋同位体第3段階の海面の潜在的遅延を含む氷河期間の海面変動に関する洞察を提供している.
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