まとめ
南米の空気サンプルでは,熱帯圏の硫黄濃度が低いことが明らかになり,自然背景濃度を示唆しています. これらの発見は,細粒子のモードでのエアロゾール硫黄のベースラインを表す可能性があります.
科学分野:
- 大気化学 大気化学
- 環境科学 環境科学
- 地質化学 地質化学
背景:
- トロポスフィアの硫黄濃度は,大気中のプロセスと空気の質を理解するために極めて重要です.
- 特に北半球における都市外の硫黄濃度に関する以前の研究では,より高い値が得られた.
- 自然のアエロゾール硫黄の基準を確立することは,環境モニタリングに不可欠です.
研究 の 目的:
- 南米の熱帯圏硫黄の背景濃度を測定する.
- 南米の硫黄濃度と北半球で報告された硫黄濃度を比較する.
- 測定された濃度が自然背景レベルを表しているかどうかを評価する.
主な方法:
- 1976年から1977年にかけて,南米の8つの異なる場所からエアロゾールサンプルが採取されました.
- 6段階のカスケードインパクターを使用して,細粒子の硫黄濃度 (約. 1マイクロメートルの空気力学直径).
- タイムシーケンスのフィルターサンプルを,海洋噴霧に関連する硫黄濃度以外の硫黄濃度について分析した.
主要な成果:
- 微粒子モードのトロポスフィアの硫黄の背景濃度は,空気立方メートルあたり約50ナノグラムでした.
- 非海洋噴霧に関連する硫黄の平均濃度は,立方メートルあたり約85ナノグラムであることが判明しました.
- これらの南米の値は,以前に発表された北半球の非都市値よりも大幅に低い.
結論:
- 南米で測定された硫黄濃度は,自然に発生したトロポスフィアの背景レベルを表している可能性があります.
- この調査結果は,大気中の硫黄の成分が地域によって異なる可能性があることを示唆している.
- これらの自然背景レベルとその影響を確認するためにさらなる研究が必要である.
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