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アイソトープモデリングによるハインリッヒイベント4の持続時間と淡水放出量の制限
D Roche1, D Paillard, E Cortijo
1IPSL/Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS, 91191 Gif sur Yvette, France. roche@lsce.saclay.cea.fr
Nature
|November 19, 2004
まとめ
ハインリッヒ事件は,急激な気候の冷却エピソードでした. ハインリッヒ事件4に関する新しい研究は,それらはより短く,以前に考えられていたよりも少ない氷を放出し,気候への影響を潜在的に軽減する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
- 気候モデリング
- 海洋学 海洋学とは
背景:
- ハインリッヒ現象は,北大西洋の氷床の不安定性に関連して,氷河期間の気候の急激な冷却イベントです.
- 物理的なメカニズムはモデル化されているが,ハインリッヒ現象の定量的な特徴は依然として十分に理解されていない.
研究 の 目的:
- ハインリッヒイベント4をシミュレートするには (約. 4万年前) で,中間複雑性の気候モデルを用いた.
- ハインリッヒイベントの期間と氷の放出に関する定量的な推定を精査する 4.
主な方法:
- 海洋の酸素同位体分布を組み込んだ気候モデルを利用した.
- モデルシミュレーションを,北大西洋の堆積物中でのフォラミニフェラルカルシートからの酸素同位体データと比較した.
主要な成果:
- ハインリッヒ事件4の期間が250 +/- 150年であることを決定しました.
- 海平面2 +/- 1mの海平面相当でハインリッヒイベント4の量化氷の放出.
- 以前の見積もりと比較して,不確実性が著しく低下した (最大2000年,海面15m相当).
結論:
- ハインリッヒイベント4はより短く,氷の放出が以前よりも少ないと推定されました.
- ハインリッヒ現象による気候と海面への影響は,これまで考えられていたより軽度であったかもしれない.
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