Reassessment of dissolved DMSP concentrations and turnover flux in the ocean

南阿拉巴马大学的研究人员将评估在各种海洋系统中测量生物可利用的二甲基磺酸丙酸酯(DMSPd)及其周转率的新方法。DMSPd在上层海洋中快速循环，被认为是微生物群落的碳和硫的来源。此外，它被认为是DMS的主要前体，DMS是一种参与大气硫循环的挥发性硫化物，DMS是一种气候活跃的气体。然而，基于先前研究得出的关于DMSPd循环某些组成部分的结论可能是错误的，因为对其溶解浓度的测定不准确。将在该项目期间提供的新信息将用于重新评估海洋表层海洋碳和硫循环以及作为海洋海洋系统的前驱物质的作用。这项工作的第一个目标包括确定河口、沿海和海洋水域中溶解的DMSP池的生物可利用部分。第二个目标将是评估现有的分析方法，以确定它是否高估了DMSPd的生物可用部分。第三和第四个目标侧重于这种化合物的方法和周转速率的量化，第五个目标侧重于利用这一速率信息来评估DMSPd是否是海洋微生物群落碳和硫的重要来源。然而，对这些通量的了解是不确定的，这项工作将消除大量这种不确定性。DMSP循环引起了包括生物地球化学、生态学和大气科学在内的多个学科的科学家的兴趣。海洋-大气痕量气体交换对气候反馈具有重要意义，DMS是影响大气的海洋气体的一个重要例子。作为该项目的一部分，将对一名研究生、一名本科生和一名研究技术员进行培训，并将启动若干涉及公共宣传和教育的活动。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Researchers at the University of South Alabama will evaluate new approaches for measuring the biologically available pool of dimethylsulfoniopropionate (DMSPd) and its turnover rate in a variety of marine systems. DMSPd is rapidly cycled in the upper ocean and is thought to be a source of carbon and sulfur for microbial communities. In addition, it is believed to be a major precursor for DMS, which is a volatile sulfur compound that is involved in the atmospheric sulfur cycle and DMS is a climate-active gas. However, conclusions regarding certain components of the DMSPd cycle that are based on prior research might be in error because of inaccurate determinations of its dissolved concentration. The new information that will be developed during this project will be used to reevaluate the role of DMSPd in the carbon and sulfur cycles of the surface ocean and as a precursor of DMS. The first objective of the work includes determining the biologically available fraction of the dissolved DMSP pool in estuarine, coastal and oceanic waters. The second objective will be to assess the existing analytical procedure to determine if it overestimates the biologically available fraction of DMSPd. The third and fourth objectives focus on the methods for, and quantifying the turnover rates of, this compound, and the fifth objective is focused on utilizing this rate information to assess whether DMSPd is a significant source of carbon and sulfur for marine microbiological communities.DMSP may have some of the highest mass fluxes through the ocean system of any single known compound. However, knowledge of those fluxes is uncertain and this work will remove a lot of that uncertainty. DMSP cycling is of interest to scientists from a broad range of disciplines including biogeochemisty, ecology and atmospheric science. Oceanic-atmospheric trace gas exchange is important to the climate feedbacks, and DMS is an important example of ocean-produced gases that can influence the atmosphere. One graduate student, one undergraduate student and one research technician will be trained as part of this project, and several activities involving public outreach and education will be initiated.