アジアのモンスーンによって,大気圏に汚染物質が運ばれる
William J Randel1, Mijeong Park, Louisa Emmons
1National Center for Atmospheric Research, Boulder, CO, USA. randel@ucar.edu
Science (New York, N.Y.)
|March 27, 2010
まとめ
地表からの空気は,アジアのモンスーンを通って平流圏に移動します. この経路は,水素シアン化物 (HCN) の測定を用いて特定され,それが典型的な熱帯航空輸送を回避することを示しています.
科学分野:
- 大気化学 大気化学
- 大気ダイナミクス 大気ダイナミクス
- 気候科学 気候科学
背景:
- ストラトスフィアの空中輸送は,化学的および気候的プロセスにとって極めて重要です.
- ブルワー・ドブソン循環は,熱帯熱帯圏から平流圏への輸送の主なメカニズムです.
- 準層圏への地域的な汚染経路を理解することは,大気モデリングに不可欠です.
研究 の 目的:
- 表面からアジアモンスーンシステムを通って平流圏に空気質の輸送を特定し,特徴づけること.
- 一般的な熱帯上流からモンスーン駆動の平流圏輸送を区別するために.
主な方法:
- 水素シアン化物 (HCN) の衛星観測を用いて,熱帯圏汚染のトレーサーとして.
- 空気質の起源と経路を追跡するためにHCN濃度を分析する.
- トロピカル上のトロポスフィアとストラトスフィアのHCNレベルを,海洋の既知のシンクと比較する.
主要な成果:
- バイオマス燃焼による汚染物質である水素シアン化物 (HCN) が,アジアモンスーンを通って地表から平流圏に輸送されていることが観察されました.
- 熱帯上層熱帯圏の空気は,大洋の沈殿物によりHCNがほとんど枯渇しており,広範囲の熱帯上流が平流圏の空気の主な源ではないことを示しています.
- アジアのモンスーン循環は,大陸の汚染が地球上の平流圏に侵入する重要な経路として機能します.
結論:
- アジアのモンスーンシステムは,表面汚染を平流層に注入するための,これまで過小評価されていた重要な経路です.
- この発見は,平流圏の化学,空気の質,気候モデリングに重大な影響を及ぼします.
- 地域的な汚染現象は,地球上の平流層の構成に直接的な影響を及ぼします.
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