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，并通过参数化所得数据来预测气溶胶-云相互作用，从而研究其气候效应。该假设是，某些生物源的挥发性有机化合物衍生的SOA增强酸性硫酸盐气溶胶内的水反应，将作为更有效的冰核粒子（INP）和不太有效的云凝结核（CCN），由于生产高粘度和低吸湿性的有机硫酸盐。 这项研究有望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。富含有机硫酸盐的SOA由异戊二烯、β-carbellene和α-pinene的氧化产生，以及北卡罗来纳州大学合成的真正的有机硫酸盐（OS），在本项目期间，将系统地检查其INP和CCN属性。将使用化学表征方法来识别富含OS的SOA中改变其INP和CCN性质的关键物质。本研究的主要目的是：（1）确定化学成分、相态和形貌如何影响富OS SOA的CCN和INP活性：（2）测量和量化化学成分和相态如何影响富OS SOA在大气老化过程中的云激活特性;以及（3）开发参数化以概括SOA化学成分的影响，CCN上的相位和混合状态/该奖项反映了NSF的法定使命，并被认为值得支持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。

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.