大气氧化能力的短期变化
Martin R Manning1, David C Lowe, Rowena C Moss
1IPCC Working Group I Support Unit, Boulder, Colorado 80305, USA. Martin.Manning@noaa.gov
Nature
|August 19, 2005
概括
大气中基 (OH) 度没有长期趋势,但呈现短期变化. 放射性碳测量显示,在重大火山爆发和火灾发生后,月度变化和显著下降.
科学领域:
- 大气化学 大气化学
- 气候科学 气候科学
- 环境监测 环境监测
背景情况:
- 基 (OH) 是主要的大气氧化剂,对于去除微量气体和调节大气"清洁"能力至关重要.
- 了解OH度趋势和变异性对于评估大气自我净化过程的变化至关重要.
- 在大气科学中,量化短期 (每年至每月) 的OH变化一直是大气科学的一个重大挑战.
研究的目的:
- 量化基度的短期变化和长期趋势.
- 使用放射性碳测量作为大气OH度的诊断工具.
- 调查火山喷发和野火等重大事件对OH水平的影响.
主要方法:
- 分析了来自新西兰和南极洲清洁空气地点的含有放射性碳 (14CO) 的一氧化碳13年的记录.
- 应用模型研究来纠正14CO生产中已知的变化.
- 使用14CO作为代理来诊断基度的短期变化.
主要成果:
- 在13年的研究期间,没有发现基度的长期显著趋势.
- 在OH度中发现了反复出现的短期变化 (约10%),持续数月.
- 观察到OH度的显著下降 (高达20%),与1991年Mt. 皮纳图博火山喷发和1997年印度尼西亚火灾.
结论:
- 基度表现出显著的短期变化,但缺乏基于此数据集的可辨认的长期趋势.
- 主要的大气事件,如大型火山爆发和广泛的野火,可以暂时降低OH度.
- 放射性碳测量为监测短期大气氧化剂动态提供了宝贵的工具.
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