プレオセンの暖かさの中でラニーニャを冷やすのか?
1Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK.
まとめ
過去の温暖期におけるエルニーニョ-南方振動 (ENSO) ダイナミクスについて議論されています. 証拠によると,エルニーニョではなく,ラニーニャのような状態がプレオセーン時代に支配され",海洋温度調節器"効果を示唆しています.
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
- 海洋学 海洋学 海洋学
- 気候科学 気候科学
背景:
- 地球温暖化と気候変動におけるエルニーニョ・サザン振動 (ENSO) の役割が議論されている.
- 過去のENSO状態を理解することは,将来の気候変動対策を予測するために極めて重要です.
研究 の 目的:
- 温暖なプレオセンの初期から中期にかけてのENSO条件を調査する.
- 継続的なエルニーニョのような状態と,ダイナミックな海洋反応の仮説を検証するために.
主な方法:
- プレオセンの古熱計を用いて海面温度を再構築した.
- 赤道太平洋における熱線傾きと上昇の証拠を分析した.
主要な成果:
- 熱線線傾きと冷流の上昇が増加した証拠が発見され,ラニャのような状態を示唆しています.
- この期間にエルニニョのような温暖な状態が持続するという以前の提案に矛盾した.
- 熱帯太平洋の加熱が東の冷却を誘導するダイナミックな"海洋温度調節器"を観測した.
結論:
- プレオセンの初期から中期には,動的なENSOが特徴となり,ラニーニャのような状況が好ましいと考えられる.
- これが示唆しているのは,
- オーシャン・サーモスタット・サーモスタット
- 熱帯太平洋の温度を調節するメカニズムである.
- 発見は,持続的な温暖化シナリオの下での海洋-大気相互作用の洞察を提供します.
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