SGER: Atmospheric Chemistry and Air-Water Exchange of Halogenated Organic Compounds in the Remote South Pacific

本项目将试图确定大气中羟基（OH）自由基在消耗南半球持久性有机污染物（POP）方面的重要性。重点将是多氯联苯。基于实验室得出的反应速率，大气消耗反应应该是去除难降解有机化合物的关键过程。然而，这并没有反映在实地测量中的丰度上。该项目将利用R/V Roger Revelle即将举行的巡航。巡航航迹将通向生物活动非常低的南太平洋环流。这将防止水柱过程在多氯联苯浓度方面主导大气反应。此外，该地点将远离多氯联苯的主要和次要来源。稍后将在实验室收集和分析大气和水样本。据推测，白天和晚上观察到的浓度之间会有很大的差异，这将为大气中多氯联苯的去除提供证据。预计这项研究将有助于更好地了解持久性有机污染物的大气反应性，这是了解其大气迁移和归宿的关键。该项目将为一名研究生提供部分支持。研究成果也将纳入课堂教学。

This project will attempt to determine the importance of atmospheric hydroxyl (OH) radical in depleting persistent organic pollutants (POPs) in the Southern Hemisphere. The focus will be on polychlorinated biphenyls (PCBs). Atmospheric depletion reactions should be key processes for the removal of recalcitrant organic compounds based on laboratory-derived reaction rates. This, however, is not reflected in their abundance in field measurements. The project will take advantage of an upcoming cruise by the R/V Roger Revelle. The cruise track will lead to the South Pacific gyre where there is very low biological activity. This will prevent water column processes from dominating over atmospheric reactions with respect to PCB concentrations. Also, the location will be far away from primary and secondary sources of PCBs. Atmospheric and water samples will be collected and analyzed later in the laboratory. It is hypothesized that there will be a significant difference between concentrations observed during the day and at night, which will provide evidence for atmospheric removal of the PCBs. This study is expected to contribute towards a better understanding of the atmospheric reactivity of persistent organic pollutants, which is key to understanding their atmospheric transport and fate. The project will provide partial support for a graduate student. Research results will also be included in classroom teaching.