北極の氷床の積もりが遅れたのは,太陽熱の変動の40万年最小値の間であった
Qingzhen Hao1, Luo Wang, Frank Oldfield
1Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China. haoqz@mail.iggcas.ac.cn
Nature
|October 5, 2012
まとめ
中国のロエス高原からの過去の気候データは,弱い東アジアの冬季モンスーン (EAWM) 風が北極で穏やかな非氷河状態を長引かせたことを明らかにしています. この発見は,将来の気候変動シナリオについての洞察を提供します.
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
- 四次地質学 四次地質学
- 気候のダイナミクス
背景:
- 北極の高緯度における過去の気候の変動を理解することは,将来の気候変動を予測する上で極めて重要です.
- 北半球の氷床の長期記録は稀で,ベンシック (18) O記録は両極の氷の量を統合している.
- 北半球の氷床の影響を受けた東アジアの冬季モンスーン (EAWM) は,北極の気候変動の代理として機能することができます.
研究 の 目的:
- 過去の北極気候の変動をEAWMを代理として使用して再構築する.
- 氷河期間の期間と特性を調査し,北緯度の高い地域への影響を調査する.
主な方法:
- 過去90万年にわたる中国ロエス高原のロエス部分の粒子の大きさの変動の分析.
- EAWMの強度のプロキシとしてエオリアン塵の堆積物を利用する.
- EAWMの変動と天文周期 (離心率と前進) を相関させる.
主要な成果:
- ロースの粒サイズデータを用いて,EAWMの90万年のプロキシ記録が作成されました.
- 特定の40万年周期の間,弱いEAWMは,氷河期間の後の20,000年間まで持続しました.
- これは,他のほとんどの氷期間の後のEAWMの急速な増加と対照的です.
結論:
- 弱いEAWM風は,シベリアの高気圏の活動が低下したため,以前考えられていたよりも長く穏やかな北極の条件を維持しました.
- この延長された非氷河期は,65°Nの夏の低温の低温と関連しており,氷の蓄積を抑制しています.
- この発見は,氷河間から氷河間への移行に関する従来のロースと海洋酸素同位体記録に異議を唱えるものである.
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