まとめ
世界的なメタンのレベルは1978年から1987年の間に11%上昇した. トロポスフィアのメタンの増加は,平流層の水蒸気を大幅に増加させ,極地平流層の雲形成に潜在的に影響を及ぼしている可能性があります.
科学分野:
- 大気化学 大気化学
- 気候科学 気候科学
背景:
- メタンは大気中の濃度が増加する強力な温室効果ガスです.
- トロポスフィアのメタンのレベルは,ここ数十年で著しく上昇傾向を示しています.
研究 の 目的:
- 1978年から1987年までの世界の熱帯圏メタンの混合比率の動向を分析する.
- 上昇するメタンが平流層の水蒸気と極地平流層の雲形成に与える潜在的な影響を調査する.
主な方法:
- グローバルな大気中のメタン測定の分析.
- メタンの増加率の統計的評価.
- 潜在的平流層水蒸気変化をモデリングする.
主要な成果:
- 世界平均の熱帯圏メタンは,1978年から1987年にかけて11% (1.52から1.684ppmv) 増加した.
- 年間成長率は約0.016ppmv/年であり,過去5年間でわずかに減少した可能性がある.
- エルニーニョ・サザン・オシレーションやエル・チコンのイベントが地球規模のメタンに有意な影響を及ぼすことは検出されなかった.
結論:
- トロポスフィアのメタン濃度の上昇は,2世紀以上にわたり,平流層の水蒸気を最大45%増加させた可能性がある.
- ストラトスフィアの水の増加は,極地ストラトスフィアの雲の形成を促進する可能性があります.
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