The hygroscopic properties of biomass burning aerosol from Eucalyptus and cow dung under different combustion conditions
The hygroscopic properties of biomass burning aerosol from Eucalyptus and cow dung under different combustion conditions
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DOI：
10.1080/02786826.2023.2198587
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发表时间：
2023-04
影响因子：
5.2
通讯作者：
Megan Mouton;K. Malek;Markiesha James;R. Pokhrel;M. Fiddler;A. Asa-Awuku;S. Bililign
中科院分区：
文献类型：
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作者：
Megan Mouton;K. Malek;Markiesha James;R. Pokhrel;M. Fiddler;A. Asa-Awuku;S. Bililign
摘要 气溶胶的吸湿性增长因其对大气光散射和消光的影响而引起人们的关注。了解吸湿特性对于预测气溶胶对云形成、区域能见度、气候影响和肺部沉积的影响至关重要。之前的研究使用了复杂气溶胶的替代成分；对生物质燃烧气溶胶等复杂多组分气溶胶的应用受到限制。我们使用两种技术报告了加湿烟雾室中来自桉树和牛粪的生物质燃烧气溶胶的气溶胶吸湿性参数：（1）使用空腔衰荡光谱仪测量气溶胶的消光吸湿增强因子f（RH）并使用经验方程推导吸湿性参数；（2）直接使用云凝聚核计数器（CCNC）。基于在不同燃烧条件下对相同燃料的重复测量，并通过修正燃烧效率（MCE）进行量化，我们发现气溶胶吸湿性取决于两种燃料类型，并在某种程度上取决于燃烧条件。对于类似的 MCE，牛粪与桉树相比始终具有更大的吸湿性值。吸湿性测量值范围为 0.024 至 0.577，MCE 测量值范围为 0.73 至 0.99。具体而言，牛粪的亚饱和吸湿性参数值为0.024-0.131，桉树为0.012-0.300，而牛粪的过饱和吸湿性参数值为0.071-0.577，桉树为0.021-0.494。使用 CCNC 测量过饱和牛粪时，随着 MCE 的增加，吸湿性明显增加，但 kappa 对 MCE 的依赖性通常是不确定的。图解摘要
Abstract Aerosols hygroscopic growth is of current interest due to its effect on atmospheric light scattering and extinction. Knowledge of hygroscopic properties is essential for predicting the effect of aerosol on cloud formation, regional visibility, climate impact, and lung deposition. Previous studies have used surrogate components of complex aerosol; and the application to complex multi-component aerosol like biomass burning aerosol is limited. We report aerosol hygroscopicity parameter of biomass burning aerosol derived from Eucalyptus and cow dung in a humidified smog chamber using two techniques: (1) measuring extinction hygroscopic enhancement factor f(RH) of aerosol using a cavity ring down spectrometer and deriving the hygroscopicity parameter using empirical equations and (2) directly using a Cloud Condensation Nuclei Counter (CCNC). Based on repeated measurements of the same fuel under different burning conditions, quantified by the modified combustion efficiency (MCE), we found that aerosol hygroscopicity depends on both fuel types and to some extent on burning conditions. For similar MCE, cow dung has a consistently larger value of hygroscopicity compared to Eucalyptus. Hygroscopicity measurements ranged from 0.024 to 0.577 for MCE measurements that ranged from 0.73 to 0.99. Specifically, sub-saturated hygroscopicity parameter values for cow dung are 0.024–0.131 and Eucalyptus are 0.012–0.300, while supersaturated hygroscopicity parameter values for cow dung are 0.071–0.577 and Eucalyptus are 0.021–0.494. There is a clear increase in hygroscopicity with increasing MCE for supersaturated cow dung measurements using CCNC but the dependence of kappa on MCE is generally inconclusive. Graphical Abstract