协同的HNO3-H2SO4-NH3上层热层粒子形成
Mingyi Wang1,2,3, Mao Xiao4, Barbara Bertozzi5
1Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA, USA.
Nature
|May 18, 2022
概括
上层热带层的新粒子形成是由酸,硫酸和氨酸之间的协同反应驱动的. 这一过程显著增强了云凝聚核 (CCN) 和冰核粒子的形成.
科学领域:
- 大气化学
- 云物理
- 气溶科学
背景情况:
- 上层热带层的新粒子形成是云凝聚核 (CCN) 的关键来源.
- 驱动这个过程的特定前体蒸气仍然不太清楚.
- 之前人们认为氨被云滴吸收,限制了它在上层热层粒子形成中的作用.
研究的目的:
- 研究酸,硫酸和氨在高热层条件下对新粒子形成的协同作用.
- 确定这些粒子的形成速度和生长机制.
- 评估这些粒子作为云凝聚核和冰核粒子的作用.
主要方法:
- 在CERN CLOUD室进行的实验模拟了上层热层条件.
- 分析粒子形成速度和增长动态.
- 使用模型模拟来确认大气运输和核化过程.
主要成果:
- 酸,硫酸和氨酸在协同作用下以比任何两种成分组合更快的速度形成颗粒.
- 氨和酸的共同凝结导致粒子迅速增长到CCN大小,即使硫酸盐最小.
- 这些CCN的功能是高效的冰核粒子,类似于沙漠尘埃.
- 模型模拟证实了亚洲季风期间有效的氨运输,推动了核和冰核粒子的传播.
结论:
- 协同的HNO3-H2SO4-NH3核化机制是高层热层中CCN形成的主要途径.
- 氨在高热层粒子形成和生长中起着至关重要的作用,特别是在亚洲季风等地区.
- 由此产生的粒子作为重要的冰核粒子,影响北半球云的特性和气候.
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