Identification of Cloud-Nucleating and Ice-Nucleating Biological Aerosol Sources

该项目侧重于实验室实验，以提供了解和预测海洋排放对大气中云形成的影响所需的定量数据。这项工作的主要目标是：(1)确定哪些浮游植物群是最有效的气溶胶制造者；(2)确定在浮游植物的水华周期中，浮游生物产生气溶胶最有效的时间；(3)对于最有效的气溶胶产生者，确定气溶胶中负责激活云形成的特定成分。该项目将提供关于海洋生态系统结构和功能与大气中云形成之间联系的基本信息。代表性的浮游植物群，包括蓝藻、硅藻和球石藻，将在一个大的中生态池中生长，浮游植物的生长将通过测量叶绿素浓度的变化密切跟踪。气溶胶将从中大气的地表水中产生，以确定哪些生物是气溶胶、云凝结核（CCN）和冰核（IN）最有效的产生者。一套生物和化学技术将用于表征气溶胶的云核和冰核特性。该项目将为实际海洋的现场测量提供见解。研究人员将在另一个项目中进行额外的CCN分离实验，该项目涉及2015-2020年在北大西洋进行的四次巡航。因此，通过本研究进行的分馏实验将提供与现场测量的直接比较。

This project focuses on laboratory experiments to provide the quantitative data needed to understand and predict the impacts of marine emissions on cloud formation in the atmosphere. The primary objectives of this effort are: (1) Determine which phytoplankton groups are the most effective producers of aerosols; (2) Determine when in the bloom cycle of the phytoplankton the organisms are the most effective in producing aerosol; and (3) For the most effective aerosol producers, identify the specific components of the aerosol that are responsible for activating cloud formation.This project will provide fundamental information on the linkages between marine ecosystem structure and function and cloud formation in the atmosphere. Representative phytoplankton groups, including cyanobacteria, diatoms, and coccolithophores, will be grown in a large mesocosm tank Phytoplankton growth will be followed closely by measuring changes in the concentrations of chlorophyll. Aerosols will be generated from the surface water of the mesocosm to identify which organisms serve as the most effective generators of aerosol, cloud condensation nuclei (CCN), and ice nuclei (IN). A suite of biological and chemical techniques will be used to characterize the cloud-nucleating and ice-nucleating properties of the aerosol.This project will provide insight for field measurements in the real ocean. The researchers will perform additional CCN fractionation experiments during a different project that involves four cruises in the North Atlantic to take place in 2015-2020. Hence, the fractionation experiments conduct through this research will provide a direct comparison to field measurements.