热带森林所维持的大气氧化能力
J Lelieveld1, T M Butler, J N Crowley
1Max Planck Institute for Chemistry, 27 Becherweg, 55128 Mainz, Germany. lelieveld@mpch-mainz.mpg.de
Nature
|April 11, 2008
概括
热带森林释放挥发性有机化合物 (VOC),这些化合物令人惊地保持了大气中高基 (OH) 水平. 这表明大气自我清洁的自然机制,即使在原始环境中也是如此.
科学领域:
- 大气化学 大气化学
- 生物地质化学生物地质化学
- 环境科学 环境科学
背景情况:
- 陆地植被,特别是热带雨林,向大气中排放大量挥发性有机化合物 (VOC).
- 大气氧化,主要由基基 (OH) 驱动,去除这些VOCs.
- 以前,人们认为生物源的VOC会在未受污染的空气中耗尽OH,降低大气氧化能力.
研究的目的:
- 为了调查大气中亚马逊雨林上的微量气体度.
- 为了了解观察到的高基 (OH) 度的意想不到.
- 探索生物源的VOC氧化的作用,在低氧化 (NOx) 的环境中保持大气氧化能力.
主要方法:
- 在亚马逊森林上空对大气微量气体的基于飞机的测量.
- 大气化学模型. 大气化学模型.
- 实验室实验研究异烯氧化机制.
主要成果:
- 在原始的亚马逊大气中观察到出乎意料的高度的基 (OH).
- 提出自然VOC的氧化,特别是异烯,在低NOx条件下有效回收OH.
- 模型计算和实验室结果表明,在异烯氧化过程中OH回收效率为40-80%,这解释了观察到的高OH水平.
结论:
- 生物圈在通过高效的OH回收来维持大气氧化平衡方面发挥着至关重要的作用.
- 生物源的VOC氧化是调节大气化学的重要因素,即使在偏远,未受污染的地区.
- 需要进行进一步的实验室研究,以充分阐明在异烯氧化中OH循环利用背后的化学机制.
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