最後の脱氷期における海洋冷度の逆転
B Stenni1, V Masson-Delmotte, S Johnsen
1Department of Geological, Environmental and Marine Sciences, University of Trieste, Trieste, Italy. stenni@univ.trieste.it
まとめ
南極の氷の核は,大気循環の変化に関連した南極冷逆の800年後の海面温度変化を示しています. これは,南インド洋における海洋冷却の逆転を明らかにしている.
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
- 海洋学 海洋学 海洋学
背景:
- 氷の芯は,過去の気候条件の貴重なアーカイブを提供します.
- 氷芯のデウテリウム過剰は,水分源の温度と大気中の水蒸気特性の代理です.
- 南極における氷の塊化に関する欧州プロジェクト (EPICA) のドームCの氷芯は,南極の気候の歴史を高解像度で記録しています.
研究 の 目的:
- 南大洋の水源地域における海面温度 (SST) の変化を再構築する.
- 最後の脱氷期における気候現象のタイミングと規模を,氷芯データを用いて決定する.
- 海洋の気温グラデーションと大気循環の強さの関係を調査する.
主な方法:
- ドームC EPICAの氷芯からのデュテリウム過剰プロフィールの詳細な分析.
- デウテリウム過剰データと他の古気候プロキシ (例えば,ナトリウム濃度) の相関.
- 過去の海面温度と大気循環パターンの推論.
主要な成果:
- 南インド洋では,南極冷逆の800年後に発生する,明確な海洋冷逆が特定されました.
- デュテリウムの過剰プロファイルは,ドームCの降雨源地域における海面温度の大幅な変化を示している.
- 温度の梯度 (海洋の水分源から南極まで) とドームCのナトリウムプロファイルの間に強い相関が観察され,脱氷期間の大気循環の強さを反映した.
結論:
- この研究は,氷河期から氷河期間の気候変動への海洋の反応が遅れていることを確認しています.
- この発見は,大洋の水分源と南極の間の気温グラディエントが,大気循環パターンを推進する上で果たす重要な役割を強調している.
- 南極の氷の核におけるデウテリウムの過剰は,過去の海洋大気動態を理解するための強力なツールです.
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