纯生物粒子的离子诱导核化
Jasper Kirkby1,2, Jonathan Duplissy3,4, Kamalika Sengupta5
1Goethe University Frankfurt, Institute for Atmospheric and Environmental Sciences, 60438 Frankfurt am Main, Germany.
Nature
|May 27, 2016
概括
新的研究表明,高氧化生物蒸汽可以在没有硫酸的情况下形成气溶颗粒. 银河系宇宙射线显著提升了这种离子诱导的核形成过程,影响了云的形成.
科学领域:
- 大气化学与物理
- 气候科学
- 气溶科学
背景情况:
- 大气中的气溶影响气候,但它们在云凝聚核 (CCN) 生产中的形成和作用尚未完全理解.
- 硫酸传统上被认为是粒子核化必不可少的,而离子则起到较小的作用.
- 之前的研究表明没有硫酸的有机颗粒形成, 但污染是令人担忧的.
研究的目的:
- 在大气条件下,在没有硫酸的情况下,从高度氧化的生物气体中研究气溶颗粒的形成.
- 确定离子,特别是来自银河系宇宙射线的作用,
- 提供实验证据支持有机分子相互作用的理论计算.
主要方法:
- 使用大型大气模拟室研究α-pinene的臭氧化,产生高氧化分子 (HOMs).
- 在中性条件下的粒子核化速率与来自银河系宇宙射线的离子影响的条件进行比较.
- 进行量子化学计算以评估HOM集群的结合能量.
主要成果:
- 在不需要硫酸的情况下,从高度氧化的生物蒸汽 (HOMs) 形成气溶颗粒.
- 与中性核相比,由于离子诱导的核化,核化速率显著增加 (大小为一到两级).
- 实验结果与HOM集群结合能量的理论计算一致.
结论:
- 纯有机粒子的离子诱导核化是大气中的气溶形成的重要途径.
- 在硫酸度低的陆地环境中,这种过程可能很普遍.
- 这些发现挑战了硫酸至关重要的传统观点,并突出了生物源的VOC和离子在气溶形成中的重要性.
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