野火烟雾的短波吸收由深棕色碳气体主导
Rajan K Chakrabarty1, Nishit J Shetty1, Arashdeep S Thind2
1Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA.
概括
野火烟雾含有一种有弹性的棕色碳,可吸收阳光,对大气变暖作出重大贡献. 这一发现需要对气候模型进行修订,以获得准确的辐射强迫估计.
科学领域:
- 大气化学 大气化学
- 气候科学 气候科学
- 气溶科学 气溶科学
背景情况:
- 野火释放黑碳和棕碳,影响地球的辐射预算.
- 由于假定的光化学漂白,棕色碳的变暖效应是不确定的,导致气候模型表现不佳.
研究的目的:
- 为了量化野火烟雾气溶的短波吸收.
- 为了研究野火羽毛中棕色碳的特性和大气处理.
主要方法:
- 在美国西部野火烟雾中测量了集体尺度和粒子尺度的短波吸收.
- 分析棕色碳的光学特性,包括水不可溶性和光漂白性.
主要成果:
- 一种特定的深棕色碳类型占显著的短 (75%) 和长 (50%) 可见光吸收.
- 这种棕色碳是不溶于水的,在白天抵抗光漂白,其吸收性随着夜间处理而增加.
结论:
- 棕色碳的辐射影响是相当大的,并且比以前假设的更持久.
- 目前对棕色碳的气候模型参数化需要更新,以准确估计烟雾气溶辐射强迫和变暖潜力.
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