在模拟野火和规定的火灾条件下燃烧生物质的棕色碳排放
Chase K Glenn1, Omar El Hajj1, Zachary McQueen2
1School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, Athens, Georgia 30602, United States.
ACS ES&T air
|September 19, 2024
概括
野火条件显著影响棕色碳 (BrC) 的光吸收. 燃烧条件,如湿度,会影响BrC的特性,影响气候和空气质量.
科学领域:
- 大气化学 大气化学
- 环境科学 环境科学
- 燃烧科学 燃烧科学
背景情况:
- 棕色碳 (BrC) 是气溶中显著的吸光成分.
- 了解BrC的光吸收特性对于气候和空气质量建模至关重要.
- 野火是大气中的BrC的主要来源.
研究的目的:
- 为了研究模拟野火中发出的BrC的吸光特性.
- 为了确定燃烧条件对BrC特性的影响.
- 要区分水溶性 (WSBrC) 和水不溶性 (WIBrC) 组件的贡献.
主要方法:
- 模拟了来自美国东南部三个生态区域的燃料床中的处方火灾和野火.
- 燃料床水分含量多样化,以代表不同的火灾类型.
- 测量火灾辐射能量通过燃料床质量负载 (FREnorm) 来规范,以分类燃烧条件.
- 使用折射率 (k) 的虚构部分量化 BrC 光吸收.
- 将 BrC 分成 WSBrC 和 WIBrC 分数,并使用电喷离子质谱学分析了 WSBrC 分子.
主要成果:
- BrC的光吸收从吸收弱 (WildDuff) 到吸收适度 (Rx和Wild) 有所不同.
- BrC 的虚构折射率 (k) 与 FRE 相关性很好.
- 不溶于水的BrC (WIBrC) 的吸光率 (k) 显著高于溶于水的BrC (WSBrC).
- WIBrC的k与FREnorm相关,而WSBrC的k没有,表明不同的形成途径.
结论:
- 燃烧条件受燃料水分和成分的影响,是BrC吸光特性的关键决定因素.
- 与WSBrC相比,WIBrC在光吸收方面发挥着更重要的作用.
- 这些发现强调了需要考虑气候和空气质量模型中的火力学.
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