グローバルな炭素吸収と大気中のO2とデルタ13Cから推論されたその変動性
M Battle1, M L Bender, P P Tans
1Department of Geoscience, Guyot Hall, Princeton University, Princeton, NJ 08544 USA.
まとめ
大気中の酸素 (O2) の測定は,陸地と海洋が1991年から1997年の間にかなりの量の炭素を吸収したことを明らかにしています. これは,1980年代とは対照的に,地球のシステムによる変動的な炭素吸収を示しています.
科学分野:
- 地球システム科学 地球システム科学
- 大気化学 大気化学
- 海洋学 海洋学 海洋学
背景:
- 大気中のO2と二酸化炭素 (CO2) レベルは,世界の炭素循環プロセスによって影響を受けます.
- 1980年代の以前の推定では,ほぼ中立の陸地生物圏の炭素バランスが示唆されていた.
研究 の 目的:
- 大気中のO2測定を用いて,陸上生物圏と海洋による炭素吸収を定量化する.
- 現代の炭素吸収を過去のデータと同位体フルースの推定値と比較する.
主な方法:
- 大気中のO2濃度の時系列測定の分析.
- O2データを,デルタ13CO2 (炭素同位体比) の測定値と比較した.
- 同位体流量データを大気測定と統合する.
主要な成果:
- 陸上生物圏は1991年半ばから1997年半ばにかけて年間1.4+/- 0.8GtC,海洋は2.0+/- 0.6GtCを吸収した.
- この時期は,1980年代のほぼ中立のバランスとは異なり,陸上生物圏の急速な炭素貯蔵を示した.
- 同位体流量の推定値は,O2由来流量と一致し,可変の炭素吸収を示しています.
結論:
- 大気中のO2とデルタ13Cのデータは,世界の炭素貯蔵の年次変動の強力な信号を提供します.
- 陸上生物圏と海洋の両方とも,ダイナミックで変動する炭素吸収を示しています.
- この発見は,地球上の炭素吸収池が環境変化に敏感であることを強調しています.
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