プレオセーン時代に地球が徐々に冷たくなり,地域の気候が変化した
Ana Christina Ravelo1, Dyke H Andreasen, Mitchell Lyle
1Ocean Sciences Department, University of California, Santa Cruz, California 95064, USA. acr@es.ucsc.edu
Nature
|May 21, 2004
まとめ
地球の気候は,単一の出来事ではなく,漸進的な変化によって,400万年以上にわたって徐々に冷却されました. 低緯度の条件は,世界の気候フィードバックに大きく影響します.
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
- 気候変動のダイナミクス
- 地球システム科学 地球システム科学
背景:
- 地球の気候は,過去400万年にわたって暖かいところから冷たいところへ移行した.
- 海洋の熱伝送に及ぼす地質学的な影響が,この移行の原因であると提案されています.
- 地球温暖化と氷河化の正確な原因については,未だに議論が続いている.
研究 の 目的:
- 地球の長期的な気候変動の原因を調査する.
- 気候記録を異なる緯度で比較して冷却パターンを理解する.
- 低緯度気候と高緯度気候の感受性との関係を決定する.
主な方法:
- 高緯度,亜熱帯,熱帯の気候記録の比較分析.
- 気候の冷却のタイミングにおける地域差の検討.
- 太陽熱による変動に対する高緯度気候の感受性の評価.
主要な成果:
- 氷河期/氷河間周期の始まりは,単一の低緯度気候再編と一致しなかった.
- 地球の冷却は,突然の出来事ではなく,段階的なプロセスとして起こりました.
- 高緯度の気候の感受性は,特に200万年前以降,徐々に増加した.
結論:
- 地域間の気候の違いは,地球が徐々に冷却していることを示唆している.
- 確立された冷たい熱帯および亜熱帯の上流条件が,高緯度の感度増加に先行した.
- 平均的な低緯度の気候条件は,世界の気候フィードバックにおいて重要な役割を果たします.
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