Collaborative Research: The seasonal dynamics of CO2, primary production, and DMS in the Western Antarctic Peninsula: Measurements of pools and processes using mass spectrometry

南大洋在海洋生物地球化学和全球气候中起着关键作用。在过去的50年里，沿着南极半岛西部，冬季气温上升了5摄氏度以上，海冰的持续时间和范围大幅减少，导致了戏剧性的生态扰动。初级生产和气候活跃气体循环对WAP物理和化学环境持续变化的敏感性是理解该地区潜在的生物地球化学气候反馈的关键。该项目的目标是描述和了解初级生产力和气候活动气体二氧化碳(CO2)和二甲基硫化物(DMS)在WAP中的季节动态。该项目将研究(1)二氧化碳、温度和光照的季节变化与总初级生产量、净初级生产量和净群落生产量之间的关系；(2)地表水二氧化碳和温度的变化在多大程度上推动主要浮游植物物种组成的生态变化，并改变DMS循环中的关键过程。这项研究将使用膜进气质谱仪监测Palmer Station LTER现场周围海水中的溶解气体，并使用示踪剂化合物进行生理/生化分析。这项研究将提供关于初级生产力和WAP中溶解气体浓度与地表水文地貌和海冰覆盖有关的时间演变的前所未有的信息。实地研究将得到对碳代谢进行详细研究的模式物种的实验室实验的支持。该项目将极大地促进对该区域季节性生物地球化学动态的了解，该区域对持续的气候扰动特别敏感，对全球海洋-大气二氧化碳交换非常重要。该项目将培养两名研究生，并将纳入普林斯顿大学的本科教学计划，包括新的讲座和新的实验室模块。通过个人投资促进机构的社区活动，该项目还将有助于公共宣传和政策。

The Southern Ocean plays a key role in marine biogeochemistry and global climate. Along the Western Antarctic Peninsula (WAP), winter air temperatures have increased by more than 5 ºC over the past five decades, and sea ice duration and extent have decreased substantially, leading to dramatic ecological perturbations. The sensitivity of primary production and climate-active gas cycling to on-going changes in the physical and chemical environment of the WAP is the key to understanding potential biogeochemical climate feedbacks in this region. The objective of this project is to characterize and understand the seasonal dynamics of primary production and climate-active gases carbon dioxide (CO2) and dimethylsulfide (DMS) in the WAP. The project will examine (1) the relationships among seasonal changes in pCO2, temperature and light with respect to gross primary production, net primary production, and net community production; (2) the extent to which changes in surface water pCO2 and temperature drive ecological shifts in the dominant phytoplankton species assemblage composition, and alter key processes in the DMS cycle. The research will employ membrane inlet mass spectrometry to monitor dissolved gases in ambient seawater at the Palmer Station LTER site and conduct physiological/biochemical assays with tracer compounds. The research will provide unprecedented information on the temporal evolution of primary production and dissolved gas concentrations in the WAP in relation to surface hydrography and sea ice cover. Field studies will be supported by laboratory experiments with model species subjected to detailed studies of carbon metabolism. This project will contribute significantly to the understanding of seasonal biogeochemical dynamics in a region that is particularly sensitive to ongoing climate perturbations and important for the global air-sea exchange of CO2. The project will train two graduate students and will be integrated in the undergraduate teaching program at Princeton University, including new lectures and new laboratory modules. Through the PIs community activities the project will also contribute to public outreach and policy.