Collaborative Research: Characterizing the Cloud Formation Properties of Secondary Organic Aerosol (SOA) Formed from Aqueous Multiphase Chemical Processes

该项目的目标是通过在实验室环境中研究含有机硫酸盐的二次有机气溶胶（SOA）的化学成分、形态和相态，并通过参数化气溶胶与云相互作用的预测结果数据，来研究它们对气候的影响。假设某些生物源性挥发性有机化合物衍生的SOA通过酸性硫酸盐气溶胶中的水反应增强，由于产生高粘性和较低吸湿性的有机硫酸盐，将成为更有效的冰核粒子（INP）和较不有效的云凝结核（CCN）。这项研究预计将有助于提高对气溶胶如何影响云的形成和云的性质的理解，并将有助于减少预测未来气候的不确定性。由异戊二烯、β-石蜡烯和α-蒎烯氧化产生的富含有机硫酸盐的SOA，以及北卡罗来纳大学合成的真正的有机硫酸盐（OSs），将在本项目中系统地检查其INP和CCN性能。化学表征方法将用于识别富含os的SOA中改变其INP和CCN特性的关键物种。本研究的主要目标是：(1)确定化学成分、相态和形态如何影响富os SOA的CCN和INP活性；(2)测量和量化化学组成和相态对富os SOA在非均相羟基自由基氧化下大气老化过程中云活化特性的影响；(3)发展参数化，以概括SOA化学成分、相和混合状态对这些粒子的CCN/ in势的影响，用于势模型模拟和现场数据比较。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this project is to examine the climate effects of organosulfate-containing secondary organic aerosol (SOA) by investigating their chemical composition, morphology, and phase state in a laboratory setting, and by parameterizing the resultant data for the prediction of aerosol-cloud interactions. The hypothesis is that certain biogenic volatile organic compound-derived SOA enhanced by aqueous reactions within acidic sulfate aerosol, will serve as more effective ice nuclei particle (INP) and less effective cloud condensation nuclei (CCN), due to the production of highly viscous and less hygroscopic organosulfates. This research is expected to help improve the understanding of how aerosols impact cloud formation and cloud properties and will contribute to reducing the uncertainties in predicting future climate.Organosulfate-rich SOA produced from the oxidation of isoprene, β-caryophyllene, and α-pinene, as well as authentic organosulfates (OSs) synthesized at the University of North Carolina, will be systematically examined for their INP and CCN properties during this project. Chemical characterization methods will be used to identify the key species in the OS-rich SOA that alter their INP and CCN properties. The primary objectives of this research are to: (1) determine how chemical composition, phase state, and morphology affect the CCN and INP activities of OS-rich SOA; (2) measure and quantify how the chemical composition and phase state affect the cloud activation properties of OS-rich SOA during atmospheric aging by heterogeneous hydroxyl radical oxidation; and (3) develop parameterizations in order to generalize the effects of SOA chemical composition, phase and mixing state on the CCN/IN potential of these particles for potential model simulations and field data comparison.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.