大気中のN2Oの氷核記録は,過去10万6000年間をカバーしています
Todd Sowers1, Richard B Alley, Jennifer Jubenville
1Department of Geosciences and the EMS Environment Institute, Pennsylvania State University, UniversityPark, PA 16802, USA. sowers@geosc.psu.edu
まとめ
氷の核の記録は,10万6千年にわたる大気中の酸化窒素 (N2O) の変化を明らかにしています. 海洋および海洋からのN2O排出量は,最後の氷河期の終結の間に大幅に増加しました.
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
- バイオジオケミカルサイクル
- 大気化学 大気化学
背景:
- 氷芯は,酸化窒素 (N2O) のような微量ガスに関する重要な古大気データを提供しています.
- 生物地球化学サイクルにおけるN2Oの役割を理解することは,気候研究にとって極めて重要です.
- 以前の研究では,温室効果ガスと氷河期との関連を調査した.
研究 の 目的:
- 大気中のN2O濃度に関する10万6千年の記録を再構築する.
- 過去3万年にわたるN2Oの同位体記録を分析するために.
- 海洋対陸上のN2O生産比率と排出量の変化を調査する.
主な方法:
- 氷核サンプルから採取した微量ガス濃度の分析.
- 氷の核の記録から得られたN2Oの安定同位体分析.
- 古代大気中のN2Oレベルと同位体組成の再構築.
主要な成果:
- 10万6000年の大気中のN2O記録が確立されました.
- 同位体記録は,海洋/陸上のN2O生産比における最小のシフトを示している.
- 海と海洋のN2O排出量は,最後の氷河期の終結時に40%増加した.
結論:
- この研究は,海洋および陸上のN2O源の安定した相対的な貢献を長期間にわたって示唆しています.
- 脱氷期における観測されたN2O排出量の増加は,海洋輸出生産の強化によってのみ引き起こされるわけではない.
- 発見は,過去の気候変動の際に海洋および陸上のN2Oの動態に関する新しい洞察を提供します.
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