Cloud Forming Potential of Marine Biogenic Aerosols and Their Physiochemical Properties

本项目将研究包括浮游植物在内的多种海洋原生有机气溶胶（POA）在大气相关条件下作为有效冰核（IN）的假设。这些实验将建立在先前研究的基础上，通过实验检查亚微米大小的粒子中存在的其他海洋有机和生物成分的物理和化学特性，这些粒子最容易携带到空中，这使得这些粒子能够在什么条件下有效地发挥作用。不仅可以确定各种POA在冰点以下温度下与气溶胶生命周期相关的控制机制，而且可以推导出冰核参数化，这将使气候建模者能够在气候模型中包括冰晶和云的形成，从而更好地理解水文循环和辐射强迫。也许最重要的是，结合微光谱单粒子分析工具研究冰核的新实验方法，包括特定染色和附荧光显微镜、扫描电子显微镜（SEM）、近边缘x射线吸收精细结构（STXM/NEXAFS）光谱，以及计算机控制的扫描电子显微镜和x射线的能量色散分析（CCSEM/EDX和HRTEM/EELS）。将允许形成冰核和不形成冰核的粒子的特定物理化学性质进行对比。该项目的结果有可能改变有关非均匀冰成核的精细尺度图像的范式，从而可以改变气溶胶诱导冰成核的方式，从而改变模式中表示冰云形成过程的方式。对联邦、州和地方政府来说，更好地了解水文循环，能够预测气候变化的速率和性质，将带来巨大的长期经济效益。与劳伦斯伯克利和巴特尔太平洋西北国家实验室的科学家合作，将使研究的范围和深度得到协同扩展，并将显著提高学生的经验。它们还将为研究人员提供获得知识的机会，这些知识将通过在同行评议期刊上的出版物和在国家/国际多学科和跨学科会议上的报告传播给其他科学家。通过该项目，研究小组将延续其参与公共宣传项目并指导不同种族和国籍的男女研究生、本科生和高中生的历史。促进下一代从事尖端研究的科学家的发展，使他们能够使用最先进的分析设备，接受实验程序、定量数据分析和数值模拟技术的培训，对于理解地球海洋和大气之间的联系以及解决全球气候变化问题至关重要。

This project will investigate the hypothesis that many types of marine primary organic aerosols (POA) including phytoplankton, act as efficient ice nuclei (IN) under atmospherically relevant conditions. The experiments will build upon previous studies by experimentally examining the physical and chemical characteristics of other marine organic and biogenic constituents present in the sub-micrometer sized particles, which can be most easily carried aloft, that allow these particles to act as efficient IN and under what conditions. Not only will the governing mechanisms relevant for the aerosol life cycle at temperatures below the freezing point be identified for a variety of POA, but the ability to derive ice nucleation parameterizations, will enable climate modelers to include the formation of ice crystals and clouds in climate models for better understanding the hydrological cycle and radiative forcing. Perhaps most significantly, the novel experimental approach for studying ice nucleation in combination with micro-spectroscopic single particle analytical tools using specific staining and epifluroescence microscopy, scanning electron microscopy (SEM), near-edge x-ray absorption fine structure (STXM/NEXAFS) spectroscopy, and computer controlled scanning electron microscopy and energy dispersive analysis of x-rays (CCSEM/EDX and HRTEM/EELS), will allow the specific physiochemical properties of particles which do and do not nucleate ice to be contrasted.The results of this project have the potential to shift paradigms regarding the fine scale picture of heterogeneous ice nucleation and thus can change the way aerosol induce ice nucleation, and thus ice cloud formation processes, are represented in models. The long-term economic benefits to federal, state, and local governments of better understanding hydrological cycles and being able to predict rates and the nature of climate changes are great. Collaborations with scientists at Lawrence Berkeley and Battelle Pacific Northwest National Laboratories will allow synergistic expansion of the scope and depth of the research and will significantly enhance the experience of students. They will also provide an opportunity for the investigators to obtain knowledge that will be transmitted to other scientists through publications in peer-reviewed journals and presentations at national/international multi- and interdisciplinary conferences. The project will allow the research group to extend its history of being involved with public outreach projects and mentoring male and female graduate, undergraduate, and high school students of diverse ethnic backgrounds and nationalities. Promoting the development of the next generation of scientists engaged in cutting edge research, having access to sophisticated state-of-the-art analytical equipment, trained in experimental procedures, quantitative data analysis, and numerical modeling techniques is critical for understanding the link between the Earth's oceans and atmosphere and addressing global climate change issues.