CAREER: A Molecular Level Investigation of Halogenation as a Mechanism of Trace Gas Production and Organic Carbon Transformation at the Surface Ocean

当将氯和溴等元素添加到海洋中的有机化合物中时，就会发生卤化作用。这一过程会产生破坏臭氧层的气体。海洋中的卤化作用还不是很清楚，因为大多数含卤素的分子仍然未知。了解海水中的卤化作用非常关键，因为：(1)随着《蒙特利尔议定书》逐步停止使用人造臭氧消耗物质，卤化作用可以控制臭氧层空洞的恢复；(2)一些含有卤素的分子有助于从大气中消除二氧化碳。这一职业研究项目将开发新的分析和数据科学工具，可用于识别海洋环境中的含卤素分子。这项研究还有助于公众健康，因为众所周知，平流层臭氧层的破坏会增加皮肤癌和白内障的风险。这一职业研究项目包括提高科学素养和培训下一代科学家和政策制定者的教育活动。项目活动包括：(1)为本科生和研究生提供前沿研究培训，(2)与高中教师合作开发教材，以及(3)通过与德克萨斯州海洋赠款计划领导的既定外联计划合作，与STEM中代表性较低的社区建立关系。该NSF职业研究项目的动机是有机碳(OC)卤化同时影响碳循环和大气化学，导致平流层臭氧消耗。这一职业项目的主要研究目标是确定表层海洋中挥发性和非挥发性卤化有机碳(VHOC和HOC)形成的分子水平的化学驱动因素。为实现这一目标，将利用一系列实验室实验、学生主导的实地观察、使用高分辨率质谱仪进行的非靶向分析以及新型数据管道，以实现以下四个具体研究目标：(1)确定易发生卤化的有机碳部分，(2)确定卤化中的VHOC前体化合物并评估单一模型化合物和复杂混合物的生产效率，(3)确定HOC前体化合物，跟踪HOC产物，并预测它们的稳定性，以及(4)确定海洋中HOC的自然存在和化学特征。这些研究目标是教育目标不可或缺的一部分。将通过一年一度的本科生主导的巡游来实现海洋中的特殊角色，这些巡游将使学生接触到尖端研究。高中教师将在夏季获得资助，与首席调查员(PI)以及研究生和本科生一起为实验室实验做出贡献。国际海洋学协会和教师之间的合作将用于开发高中教学资源和海洋有机生物地球化学课程的课堂活动。这项职业研究的研究结果将被综合起来，并通过与德克萨斯州海洋赠款代理人、专家和传播者的全州网络合作，传达给代表性不足的社区。该项目将在墨西哥湾建立一个首创的特设图书馆和时间序列，为更广泛的科学界未来的特设研究提供坚实的基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Halogenation occurs when elements such as chlorine and bromine are added to organic compounds in the ocean. This process can produce gases that damage the ozone layer. Halogenation in the ocean is not well understood because most halogen-containing molecules remain unknown. Understanding halogenation in seawater is key because: (1) it may control recovery of the ozone hole as the Montreal Protocol phases out the use of man-made ozone-depleting substances and (2) some halogen-containing molecules can contribute to removing carbon dioxide from the atmosphere. This CAREER research project will develop new analytical and data science tools that can be used to identify halogen-containing molecules in the marine environment. The research also contributes to public health because damage to the ozone layer in the stratosphere is known to increase risks for skin cancer and cataracts. This CAREER research project includes educational activities to improve scientific literacy and to train the next generation of scientists and policymakers. Project activities include: (1) cutting-edge research training for undergraduate and graduate students, (2) partnerships with high school teachers to develop teaching materials, and (3) building relationships with communities underrepresented in STEM by working with established outreach programs led by the Texas Sea Grant Program.The motivation for this NSF CAREER research project is that organic carbon (OC) halogenation simultaneously affects the carbon cycle and atmospheric chemistry, contributing to stratospheric ozone depletion. The overarching research goal of this CAREER project is to identify the molecular-level chemical drivers of volatile and non-volatile halogenated organic carbon (VHOC and HOC) formation in the surface ocean. A series of laboratory experiments, student-led field observations, untargeted analyses using high-resolution mass spectrometry, and novel data pipelines will be used to achieve this goal through the pursuit of four specific research objectives: (1) identify OC moieties susceptible to halogenation, (2) identify VHOC precursor compounds in halogenation and assess production efficiency in single model compounds and complex mixtures, (3) identify HOC precursor compounds, trace HOC products, and predict their stabilities, and (4) determine the natural occurrence and chemical characteristics of HOC in the ocean. These research objectives are integral to the educational objectives. HOC characterization in the ocean will be achieved through annual undergraduate student-led cruises that will expose students to cutting-edge research. High school teachers will be funded in the summer to contribute to laboratory experiments alongside the Principal Investigator (PI) and graduate and undergraduate students. The collaboration between the PI and teachers will be used to develop high school instructional resources and classroom activities for a Marine Organic Biogeochemistry curriculum. Research results from this CAREER research will be synthesized and communicated to underrepresented communities through collaboration with the statewide network of the Texas Sea Grant agents, specialists, and communicators. This project will produce a first-of-its-kind HOC library and time series in the Gulf of Mexico that will provide a solid foundation for future HOC research by the broader scientific community.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.