太平洋東部の大気中のCH3Brのためのネットシンク
まとめ
東太平洋の地表水は,海岸付近を除いて,メチルブロミド (CH3Br) でほとんど飽和していない. この海洋の沈殿地は,大気中のCH3Brの分布とその半球間差異に影響を与えます.
科学分野:
- マリン・ケミストリー (海洋化学)
- 大気化学 大気化学
- 海洋-大気相互作用
背景:
- メチルブロミド (CH3Br) は,オゾン層を大幅に破壊する物質です.
- 海洋のCH3Brの源と沈殿地を理解することは,大気モデリングに不可欠です.
研究 の 目的:
- 東太平洋の地表水におけるメチルブロミドの飽和度を評価するために.
- 大気中のCH3Br.Br.の海洋降解速度を定量化するために.
- 半球間差異における海洋CH3Br分布の役割を調査する.
主な方法:
- 東太平洋でクルーズコースの調査を行いました.
- 表面水中のCH3Br濃度を測定する.
- 飽和度異常と部分寿命の計算.
主要な成果:
- 表面水は,CH3Brでほとんど飽和していない状態で, +100% (沿岸) から -50% (公海) の異常値を示していた.
- 大気中のCH3Brの平均海洋降解部分寿命は3.0年であると計算されました.
- 海洋の噴出源と沈殿地は,観測された半球間CH3Br差異に約8%の貢献をした.
結論:
- 東太平洋は,大気中のメチルブロミドのネットシンクとして機能する.
- CH3Brの不均等な海洋分布は,世界の大気中の濃度に大きな影響を及ぼします.
- 海洋過程は,大気中のCH3Brレベルを調節する重要な要因です.
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