流星のアブレーション,フクス,および大気への影響は,平流圏のエアロゾールから推測される
D J Cziczo1, D S Thomson, D M Murphy
1Aeronomy Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305, USA.
まとめ
ストラトスフィアのエアロゾール粒子は,有意な隕石鉄を含んでおり,毎年8~38ギガグラムの地外からの流入を示しています. 組成は,平流圏にある地球外物質がコンドリートではないことを示唆しています.
科学分野:
- 地質化学 地質化学
- 大気科学 大気科学
- コスミック・ダスト (宇宙の塵)
背景:
- ストラトスフィアのエアロゾール粒子は,大気化学と気候において重要な役割を果たします.
- これらの粒子の地球外の成分を理解することは,地球の大気中のプロセスを解読する鍵です.
研究 の 目的:
- ストラトスフィアのエアロゾール粒子の組成を分析するために.
- 地球への地球外生命体の流入を定量化するために.
- ストラトスフィアの地球外物質の起源と構成を決定する.
主な方法:
- ストラトスフィアのエアロゾールサンプルの単粒子の分析.
- 質量スペクトロメトリで元素の組成 (Fe,Na,Mg,Ca) を決定する.
- 粒子の元素比の比較とコンドリート隕石の組成.
主要な成果:
- 分析された粒子の約50%は,質量的に0.5-1.0%の隕石鉄を含んでいる.
- 推定される地球外生命体の年間流入量は8~38ギガグラムである.
- ストラトスフィアの粒子は,コンドライトと比較して,より高いNa/Fe,より低いMg/Fe,Ca/Fe比を示しています.
結論:
- ストラトスフィアの地外物質は,コンドリート起源ではない.
- 到着した地球外物質の消去分子は,おそらく以前の推定値の底辺にある.
- これらの発見は,地球の大気に対する宇宙塵の貢献に関する私たちの理解を洗練します.
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