最後の氷河期最大期におけるエルニーニョ-南方振動の減少
Heather L Ford1, A Christina Ravelo2, Pratigya J Polissar3
1Ocean Sciences Department, University of California, Santa Cruz, CA 95064, USA. Biology and Paleo Environment, Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA. hford@ldeo.columbia.edu.
Science (New York, N.Y.)
|January 17, 2015
まとめ
エルニーニョ・サザン・オシレーション (ENSO) は,深層の熱流線により,最後の氷河期最大期間の変動が減少したことを示し,それは単に温度グラデーションによって引き起こされるものではないことを示唆しています.
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:
- エルニーニョ・サザン・オシレーション (ENSO) は,世界の気候の変動の主要な原動力である.
- 最後の氷河期最大期 (LGM) のような過去の気候変動に対する ENSO の反応を理解することは,将来の気候を予測する上で極めて重要です.
- 以前の仮定は,ENSOの変動を,東西気温グラデーションと直接結び付けていた.
研究 の 目的:
- 赤道太平洋のLGM海面温度を再構築する.
- LGMの境界条件下でのENSOの行動を調査する.
- ENSOの変動性の主要な要因を再評価する.
主な方法:
- 温度再構築のための個々のプランクトンフォラミニフェラ殻の分析.
- 赤道太平洋の堆積物核から古気候データ収集.
- LGM ENSOの変異性を Holocene 後期記録と比較する.
主要な成果:
- LGM赤道太平洋の気温は,深い熱帯を明らかにしています.
- この深層の熱帯は,東方赤道の冷たい舌で海洋のダイナミクスを大幅に変化させた.
- ENSOの変動性は,後期ホロセーンと比較して,LGMの間に明らかに減少しました.
結論:
- LGM中のENSOの変動は,東西温度グラデーションによって直接制御されていませんでした.
- 深東赤道太平洋の熱流は,LGMの気候条件に対するENSOの反応を調節する上で重要な役割を果たしました.
- これらの発見は,ENSOのグローバル境界条件に対する感受性についての理解を洗練します.
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