Collaborative Research: Sizing Up the Smoke--Evaluating and Improving Our Ability to Predict Aged Wildfire Aerosol Size Distributions

这项研究的重点是研究生物质燃烧排放的老化。生物质燃烧排放的小颗粒可以在大气中发生反应，改变它们的大小、数量和成分。这些老化过程将被建模，模型结果将根据现场活动的实际数据进行测试。将研究以下问题：（1）什么化学过程与生物质燃烧排放物的分散和凝结相结合，捕获实验室和现场观察到的气溶胶尺寸和数量浓度的演变？ (2) 实验室测量的二次有机气溶胶（SOA）形成速率和粒径分布变化是否与气溶胶老化的现场测量一致？如果不是，我们能否确定原因（例如，腔室实验中缺乏连续稀释或壁损失）？ (3) 哪些特性最能决定老化生物质燃烧气溶胶的大小和数量？例如。总质量排放通量、新鲜颗粒大小、燃料类型、改良燃烧效率、风速、火灾面积、垂直混合深度、阳光。 (4) 老化生物质燃烧气溶胶大小和数量的变化是否可以通过简单的参数化来捕获，该参数化是上述属性中最重要的属性的函数？

This research is focused on studying the aging of emissions from biomass burning. Small particles emitted from biomass combustion can react in the atmosphere, changing their size, number, and composition. These aging processes will be modeled and the model results will be tested against actual data from field campaigns.The following questions will be investigated: (1) What are the chemical processes that, when combined with the dispersion and coagulation of biomass-burning emissions, capture the evolution of aerosol size and number concentrations seen in the laboratory and the field? (2) Are the secondary organic aerosol (SOA) formation rates and size-distribution changes measured in lab experiments consistent with the field measurements of aerosol aging? If they are not, can we determine why (e.g. lack of continuous dilution or wall losses in chamber experiments)? (3) What properties most strongly determine the aged biomass-burning aerosol size and number? E.g. total mass emission flux, fresh particle size, fuel type, modified combustion efficiency, wind speed, fire area, vertical mixing depth, sunlight. (4) Can the variability in aged biomass-burning aerosol size and number be captured by a simple parameterization that is a function of the most important of the above properties?