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Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
過去11万年の間に大気中のメタン濃度の急速な変動
1E. J. Brook and J. Orchardo, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA. T. Sowers, 447 Deike Building, Geosciences Department, Pennsylvania State University, University Park, PA 16802, USA.
まとめ
大気中のメタンの濃度は過去11万年にわたって大きく変動し,グリーンランドの温暖化現象と相関しています. 北半球の日照は,これらのメタンシフトに影響を与え,地上生物圏に影響を与えたようです.
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
- アイスコアの分析
- 大気化学 大気化学
背景:
- 千年スケールの気候変動の変動は,古気候記録で記録されています.
- グリーンランドの氷芯は,過去の大気条件の高解像度アーカイブを提供します.
- Dansgaard-Oeschger現象は,最後の氷河期間の突然の温暖化期間を表しています.
研究 の 目的:
- GISP2の氷核記録を用いて,過去11万年におけるミレニアムスケールメタンの変動を分析する.
- 大気中のメタン濃度の変化とダンズガード-オシュガー現象の関係について調査する.
- 氷河期間のメタンダイナミクスに対する北半球の太陽照射の潜在的影響を調査する.
主な方法:
- GISP2の氷核からのメタン濃度の分析.
- メタンのデータと Dansgaard-Oeschger イベントのタイミングの相関.
- メタンシフトの大きさと北半球の夏の太陽照射記録の比較.
主要な成果:
- GISP2の氷核は,過去11万年にわたってミレニアムスケールのメタンの変動を明らかにしています.
- メタンの濃度の急激な変化 (50〜300ppb) は,ほとんどのダンズガール・オシュガー温暖化現象と一致しました.
- メタンシフトの大きさは,より長い時間スケールで変化し,北半球の夏の太陽照射と相関しています.
結論:
- ミレニアムスケールのメタンの変動性は,過去11万年の重要な特徴です.
- Dansgaard-Oeschger現象には,大気中のメタンの急速な変化が伴いました.
- 北半球の日照は,地上の生物圏のメタン産生に対する段階間の気候変動の影響を調整した可能性が高い.
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