塵:最後の氷河期最大期間の水学サイクルを診断する
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena 91125, USA.
Science (New York, N.Y.)
|February 16, 1996
まとめ
最後の氷河期最大 (Last Glacial Maximum,LGM) 時の高い塵の濃度は,水循環が弱かったことを示唆している. この発見は,その期間に海洋の温度が大幅に下がったという証拠と一致している.
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:
- グリーンランドと南極の氷河核は,最後の氷河期最大期 (LGM) 中の高い塵の濃度を示しています.
- 以前の研究では,LGMの間に地球が著しく冷たくなったことが示されています.
研究 の 目的:
- LGMの氷核で観測された高い塵の濃度を説明するために.
- LGMにおける塵レベル,水循環強度,海洋温度の関係について調査する.
主な方法:
- 氷の核における塵の濃度の分析.
- 水循環の強さをモデリングする.
- 珊瑚の記録 (ストロンチウムとカルシウム測定) から古海洋学的データを解釈する.
主要な成果:
- 観測されたLGMの氷核における塵の増幅は,現在のレベルより約50%弱かった水循環と一致しています.
- この水循環強度の減少は,LGM期間の海洋温度 (約5°C) の大幅な低下と相関しています.
結論:
- LGMは,現在の水学サイクルと比較して,かなり弱い水学サイクルを経験しました.
- 海洋温度の低下は,おそらくLGMの間に水循環の強さと大気中の塵の輸送を調節する役割を果たした.
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