Reassessment of dissolved DMSP concentrations and turnover flux in the ocean

“该奖项是根据2009年美国复苏和再投资法案（公法111 - 5）资助的。"南亚拉巴马大学的研究人员将评估测量二甲基磺基丙酸盐（DMSPd）的生物可用池及其在各种海洋系统中的周转率的新方法。 DMSPd在海洋上层迅速循环，被认为是微生物群落的碳和硫的来源。 此外，它被认为是二甲基硫醚的主要前体，二甲基硫醚是一种挥发性硫化合物，参与大气硫循环，二甲基硫醚是一种气候活性气体。 然而，根据先前的研究得出的关于DMSPd循环某些组成部分的结论可能是错误的，因为其溶解浓度的测定不准确。在本项目期间将获得的新信息将用于重新评估DMSPd在表层海洋碳和硫循环中的作用以及作为DMS前体的作用。 工作的第一个目标是确定河口、沿海和大洋沃茨中溶解的DMSP池的生物可利用部分。 第二个目标是评估现有的分析方法，以确定其是否高估了DMSPd的生物可利用部分。 第三和第四个目标的重点是方法，量化周转率，这种化合物，和第五个目标是重点利用这一速度的信息，以评估是否DMSPd是一个重要的来源的碳和硫的海洋微生物群落DMSP可能有一些最高的质量通量通过海洋系统的任何单一的已知化合物。然而，这些通量的知识是不确定的，这项工作将消除很多不确定性。 DMSP循环是感兴趣的科学家从广泛的学科，包括地球化学，生态学和大气科学。 海洋-大气微量气体交换对气候反馈具有重要意义，二甲基硫醚是海洋产生的气体对大气产生影响的重要例子。 作为该项目的一部分，将培训一名研究生、一名本科生和一名研究技术员，并将开展若干涉及公众宣传和教育的活动。

"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.