固体アンモニアム硫酸エアロゾールは,氷の核として:シラス雲形成の経路
J P D Abbatt1, S Benz, D J Cziczo
1Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada. jabbatt@chem.utoronto.ca
まとめ
固体アンモニアウム硫酸エアロゾールは,異質な氷核形成を通じて,シラス雲の形成を促進します. この経路は,農業によるアンモニア排出の影響を受け,雲の性質と放射力強迫を変化させることで気候に影響を与えます.
科学分野:
- 大気化学 大気化学
- クラウド物理学 クラウド物理
- 気候科学 気候科学
背景:
- サールス雲は,地球の放射線バランスにおいて重要な役割を果たします.
- シラス雲,特に大陸のシラス雲の形成メカニズムは完全に理解されていません.
- 雲の発生における半球間非対称性は,特定の形成経路を示唆する.
研究 の 目的:
- 円雲の形成における固体アンモニアム硫酸エアロゾールの役割を調査する.
- これらのエアロゾールによる異質な氷の核形成が,観測されたシラス雲の性質を説明するかどうかを判断する.
- この提案されたサールス形成経路の気候への影響を評価する.
主な方法:
- 固体アンモニウム硫酸エアロゾールにおける氷核の実験室測定.
- 氷の形成条件の分析 (氷の飽和率).
- 気候モデルにメカニズムを組み込む.
主要な成果:
- 実験室のデータは,固体アンモニウム硫酸エアロゾールによる異質な氷核形成を裏付けている.
- 氷の形成は,氷の飽和度比が低い場合に発生し,大陸のサールスと一致します.
- 気候モデルのシミュレーションでは,この経路がより少ない,より大きな氷結晶を生成し,雲のアルベドと長波加熱を減らすことが示されています.
- このメカニズムは,雲の発生における半球間非対称性を説明する.
結論:
- 固体アンモニアウム硫酸エアロゾールは,シラスの形成のための氷核の重要な供給源を提供します.
- この経路は,農業によるアンモニア排出と気候システムの変化を結びつけています.
- このメカニズムは,シラス雲の放射性特性に影響を及ぼし,世界の気候に影響を与えます.
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