グリーンランドの中央部で16度Cの急速な気温変動 7万年前
1Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, Bern CH-3012, Switzerland. Niels Bohr Institute, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Den.
まとめ
研究者は,グリーンランドの氷の核の窒素同位体を分析して,過去の気候を再構築した. 過去の気候イベントで16ケルビンの著しい温度変化が観測され,これまでの推定値とは異なる.
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
- イソトープ地球化学 イソトープ地球化学
背景:
- 極地氷のコアにおける窒素同位体比 (29N2/28N2) は,過去の地表温度と氷河期-ガス年齢の差異と相関しています.
- これらの関係を理解することは,古気候条件を正確に再構築するために不可欠です.
研究 の 目的:
- 過去の地表温度変化と,特定の古気候現象における氷河期-ガス年齢の違いを正確に決定する.
- デルタ ((18) O (((氷) 温度係数の校正を精密にするために.
主な方法:
- Dansgaard-Oeschgerイベントのグリーンランド氷芯サンプルにおける窒素同位体比 (29N2/28N2) の高解像度分析 19.
- 燃焼濃縮,温度,ガス拡散モデルを組み合わせて適用する.
- デルタ18O氷の温度係数 (アルファ) の決定.
主要な成果:
- Dansgaard-Oeschgerイベント19の発生時の氷河期-ガス年齢の差は,1090 +/- 100年であると計算されました.
- デルタ18O氷の温度係数 (アルファ) は,0.42 +/- 0.05 per mil per Kelvin.と決定されました.
- これは,イベント中に平均表面温度の変化が16.0ケルビン (範囲:14.318.1ケルビン) であったことを意味する.
結論:
- 計算された温度変化は,掘削孔温度と現代の空間デルタ ((18) O (((氷) 表面温度相関を用いて得られた値と大きく異なる.
- この研究は,Dansgaard-Oeschgerイベントの間のグリーンランドのより正確な古気候の再構築を提供します.
- 氷の核における窒素同位体分析は,過去の気候動態を理解するための貴重なツールです.
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