氷核の窒素イソトープの窒素イソトープに対する人為的な影響
M G Hastings1, J C Jarvis, E J Steig
1Department of Geological Sciences and Environmental Change Initiative, Brown University, Providence, RI 02912, USA. meredith_hastings@brown.edu
まとめ
グリーンランドの氷芯は,工業化時代以来,窒素同位体比 (デルタ15N) の窒素酸塩の有意な減少を示しています. これは,人間による窒素酸化物 (NOx) 排出量の増加が,大気中の窒素化合物の組成を変えたことを示している.
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
- 大気化学 大気化学
- イソトープ地球化学 イソトープ地球化学
背景:
- 窒素酸塩の同位体成分 (デルタ15N) は,酸化窒素 (NOx) 源に対して敏感である.
- 氷芯は,過去の大気組成の貴重なアーカイブを提供します.
研究 の 目的:
- 大気中の窒素化合物の組成における歴史的変化を再構築する.
- 人為的な排出が窒素同位体に与える影響を評価する.
主な方法:
- グリーンランドのサミットから100メートルの氷芯の分析.
- 窒素同位体組成 (デルタ15N) を窒素酸塩で測定する.
主要な成果:
- 工業化期間中に,窒素のデルタ15Nの強い,明確な負の傾向が観察されました.
- 大気中の亜酸塩のデルタ15Nは,工業化以前の値から現在の値に1ミリあたり12%減少した.
- 氷の核の窒素濃度記録は,窒素酸化物 (NOx) 源からの排出量の変化を正確に反映しています.
結論:
- 人為的なNOx排出は,大気中の窒素酸塩の同位体シグネチャーを大幅に変化させた.
- 窒素の同位体組成の変動は,他の環境記録の解釈に影響を与える可能性があります.
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