Secondary Marine Aerosol precursors and Links to aerosol growth at ice-melT onset in the Arctic (SMALTA)

该项目的目标是提高对大气中二次海洋气溶胶形成的认识。与一次海洋气溶胶相比，二次气溶胶解释了海洋云凝结核和云滴数浓度变化的更大部分。这项工作预计将提高对控制偏远海洋上空气溶胶数量和性质的海洋-大气相互作用的预测性理解，并将提高对海洋云凝结核形成的机理性理解。这些结果将为气溶胶对海洋云特性和地球气候变化影响的改进模型表示提供所需的信息。挥发性有机化合物的测量将在2023年5月至6月在IB Oden上进行的大气河流和海冰融化开始（ARTofMELT）项目期间进行。含氧挥发性有机化合物的新测量将允许确定是否含氧单萜，线性羰基化合物和酚类化合物是重要的贡献者，气相海洋活性有机碳在极地海洋区域。此外，减少硫化合物的新的测量将允许确定甲烷是否在大西洋北极春季水华期间对天然硫预算做出重要贡献。最后，气体气溶胶闭合模拟将量化这些未被探索的海洋二次气溶胶前体在控制气溶胶特性方面的作用。该项目的观测和建模与北极以外的海洋区域有关，在这些区域，（1）气溶胶特性模型依赖于关于次级海洋气溶胶前体的性质和特性的假设，以及（2）努力达到测量和预测的氧化剂反应性之间的关闭，表明活性有机碳的缺失来源。三名研究生将参加国际合作，research.与科罗拉多州立大学自然科学教育和外联中心的合作将涉及设计动手和学生驱动的课堂活动，重点是温室气体及其对当地农业系统的影响，该奖项反映了NSF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进行评估，被认为值得支持审查标准。

The goal of this project is to advance knowledge about the formation of secondary marine aerosol in the atmosphere. Compared to primary marine aerosol, secondary aerosol explains a larger fraction of variability in marine cloud condensation nuclei and cloud droplet number concentrations. This work is expected to improve the predictive understanding of ocean - atmosphere interactions that control aerosol number and properties over remote oceans and will improve the mechanistic understanding of the formation of marine cloud condensation nuclei. The results will provide needed information for improved model representation of aerosol impacts on marine cloud properties and Earth’s changing climate.Measurements of volatile organic compounds will be made during the Atmospheric Rivers and the Onset of Sea Ice Melt (ARTofMELT) project aboard IB Oden, in May – June 2023. New measurements of oxygenated volatile organic compounds will allow a determination of whether oxygenated monoterpenes, linear carbonyls and phenolic compounds are important contributors to gas-phase marine reactive organic carbon in a polar marine region. In addition, new measurements of reduced sulfur compounds will allow a determination about whether methanethiol makes an important contribution to the natural sulfur budget during the Atlantic Arctic spring bloom. Finally, gas-aerosol closure simulations will quantify the role of these under-explored precursors of secondary marine aerosol in controlling aerosol properties. The observations and modeling of this project have relevance to marine regions beyond the Arctic, where (1) models of aerosol properties have relied on assumptions about the nature and identity of secondary marine aerosol precursors, and (2) efforts to reach closure between measured and predicted oxidant reactivity have indicated a missing source of reactive organic carbon.Three graduate students will participate in the internationally collaborative research. A collaboration with the Natural Sciences Education and Outreach Center at Colorado State University will involve the design of hands-on and student-driven classroom activities that focus on greenhouse gases and their impacts on both local agricultural systems, and remote ocean and polar ecosystems.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.