北大西洋のミレニアムスケールの気候変動の050万年の記録
1Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA. Salem State College, Salem, MA 01970, USA.
まとめ
海洋沈殿物の記録は,北大西洋の気候の不安定性が,氷床が重要なサイズ値を超えると増幅されることを明らかにしています. これにより,海面の温度変動が大きくなり,氷河期に氷山の排出が増加します.
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 海洋学とは
- 氷河学 氷河学とは
背景:
- サブポラー北大西洋からの海洋沈殿物の記録は,過去の気候動態の洞察を提供します.
- ミレニアムスケールの気候変動は,過去50万年以上にわたって北大西洋地域の特徴でした.
- 氷床の大きさは,地域の気候の不安定性を調節する上で重要な役割を果たします.
研究 の 目的:
- 氷床の大きさと地域的な気候の不安定性との関係を調査する.
- 増幅された気候変動の変動を誘発する氷床の成長における重要な値を特定する.
- 海面温度の変化と氷山の流出パターンを分析する.
主な方法:
- サブポラー北大西洋の長い,連続した海洋堆積物核の分析.
- 氷床の大きさを示すためのベンシック酸素同位体 (デルタ18O) 値の試験.
- 氷山の放出と海面の気温変動に関する指標の評価.
主要な成果:
- 氷床の大きさの臨界値が特定され,デルタ18O値 3.5 per mil で示されました.
- この値を超えると,海面温度と氷山の排出のミレニアムスケールの変動が著しく増加しました.
- 海面温度の振動が1-2°Cから4-6°Cに増幅され,頻繁に大きな氷山の放出が発生する.
結論:
- 氷床の大きさは,北大西洋のミレニアムスケールの気候変動の変動を拡大する重要な要因です.
- 特定された不安定性の値は,現代の氷床の構成から比較的わずかな変化で到達しています.
- ホロセンの間氷期は,氷期中に観察された増幅された不安定性の範囲の外にある安定した気候状態を表しています.
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