北極の淡水は,若いドライアスの冷たい逆転を強制する
1Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7. lev@atmosp.physics.utoronto.ca
Nature
|June 3, 2005
まとめ
ユング・ドライアスの冷却の逆転は,北極海への淡水排出によって引き起こされた. この北極の溶融水の流れは北大西洋の深水形成を混乱させ,最後の脱氷期における地球的な冷却を引き起こした.
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,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:
- この最後の脱氷期は,氷河期状態への千年規模の逆転を経験し,若年ドライアスの寒冷現象として知られています.
- この寒い時期は,北大西洋の深水形成の減少と,地表水の新鮮化による海洋循環の弱まりに関連しています.
- 以前の融水パルス (融水パルス1a) は,海洋循環を同様の方法で混乱させなかったため,淡水の影響が多様であったことを示唆しています.
研究 の 目的:
- 最後の脱氷期における淡水圧縮の地理的源を特定する.
- 若年ドライアスの寒冷現象を引き起こした可能性がある特定の淡水放出機構を調査する.
主な方法:
- 北米の氷床の排水時間表のためのシミュレーションのアンサンブルの分析.
- カリブレーションされた氷河システムモデルを使用して,淡水供給と排水経路を評価する.
主要な成果:
- 北米の氷床は,融水パルス1a.に関連した淡水のおよそ半分を供給した.
- ヤング・ドライアスの初期には,氷山の融水と氷山の排出が北極海に流れていた.
- 北極海の唯一の排水口であるグリーンランド・アイスランド・ノルウェー海への排水口が特定され,北大西洋の深水形成の重要な地域である.
結論:
- この研究では,北極海への淡水流が,若年ドライアスの寒冷逆転の主な引き金であると仮定しています.
- この北極の淡水輸入は,北大西洋の深水形成を妨害し,観測された急激な冷却につながった可能性があります.
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