Collaborative Research: SGER - Rapid Resolution of Particle Sampling Issues for GEOTRACES

利用探索性研究小额赠款（SGER）的资金，加州大学伯克利分校和伍兹霍尔海洋研究所的研究人员将于2008年夏天在大西洋海上部署多单元大容量原位过滤系统（MULVFS），参与美国- geotraces Intercalibration研究的第一阶段。较大的抽样方法偏差（据报道，瓶子和泵之间的差异高达200倍，而多例差异为3倍或更多）继续使微粒取样界感到困惑。有充分的证据表明，MULVFS颗粒物质样品不受偏差的影响。此外，这种抽样偏差远远超过了目前资助的IC粒子工作几乎专门用于解决的分析方法问题。该项目的中心目标是消除GEOTRACES项目颗粒采样对PI/采样方法的依赖，并协调项目科学阶段使用的不同采样方法。这项工作将支持多研究者使用MULVFS在环境容易的地点（如BATS）和物理动态和生物可变的地点（如墨西哥湾流）进行颗粒物相互校准研究。在具有挑战性和非挑战性的环境中与其他粒子采样方法进行比较，将导致对偏差/差异的理解和解决，这些偏差/差异在已发表的文献中都有记载，并在本提案中进一步记录。这样的内部校准以前从未做过。另一个好处是，MULVFS将通过提供上层水柱中痕量金属和核素的高分辨率基线剖面，大大提高2008年6月IC实验的效率。更广泛的影响：该项目将解决依赖于方法的颗粒取样和分析前偏差的非常现实的问题（一些泵的大颗粒损失，瓶中过滤前的显著沉降损失，样品保存不良等）。这项工作与从事粒子研究的海洋学社区的所有成员相关，因此与美国国家科学基金会化学和生物海洋学计划的广泛内容相关。

With funds from this Small Grant for Exploratory Research (SGER), researchers at the University of California at Berkeley and the Woods Hole Oceanographic Institution will participate in the first phase of the US-GEOTRACES Intercalibration study by providing deployment of the Multiple Unit Large Volume in-situ Filtration System (MULVFS) at sea in the Atlantic in the summer of 2008. Large sampling methodological biases (with one reported differences between bottles and pumps as large as a factor of 200, and multiple cases of factor of 3 or more differences) continue to confound the particulate sampling community. There is good evidence that MULVFS particulate matter samples are not subject to bias. Furthermore, such sampling biases far out weigh issues of analytical methodology issues that the currently funded IC particle work is almost exclusively designed to address.The central goal of this project is to eliminate PI/sampling approach dependency for the GEOTRACES Program particulate sampling and to reconcile the different sampling approaches to be used in the science phase of the Program. Work will support multi-investigator particulate matter intercalibration studies using MULVFS in both the environmentally easy locations such as BATS and in physically dynamic and biologically variable locations such as in the Gulf Stream. Comparison with other particle sampling methodologies in both challenging and non-challenging environments will lead to understanding and resolution of biases /differences that are both substantial, documented in published literature, and further documented in this proposal. Such an inter calibration has never been done before. A Further benefit is that MULVFS will greatly improve the efficiency of the June 2008 IC experiment by providing high resolution baseline profiles of trace metals and nuclides in the upper water column.Broader Impacts: This project will tackle the very real problems of method-dependent particle sampling and pre-analysis biases (large particle loss from some pumps, significant settling loss before filtration in bottles, poor sample preservation, etc.). The work is of relevance to all members of the oceanography community who engage in particle studies, and thus is of relevance to broad elements of the NSF Chemical and Biological Oceanography Programs.