Collaborative Proposal: Assessment of the Colloidal Iron Size Spectrum in Coastal and Oceanic Waters

GSTDTAP

项目编号	1558722
	Collaborative Proposal: Assessment of the Colloidal Iron Size Spectrum in Coastal and Oceanic Waters
	Jessica Fitzsimmons
主持机构	Texas A&M University Main Campus
项目开始年	2015
	2015-05-29
项目结束日期	2017-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	198737(USD)
国家	美国
语种	英语
英文摘要	Bioavailable iron is arguably the most important nutrient for shaping the distribution and composition of marine primary productivity and, in turn, the magnitude of ocean carbon export. Iron exists in many phases throughout the world's oceans, and colloidal, or non-soluble, phases comprise a significant fraction of dissolved iron. However, the size and physical/chemical character of these phases is presently poorly understood. To better understand this key part of iron cycling, researchers will use new analytical chemistry methods to quantitatively separate the colloidal iron sizes present in a sample and measure the composition of these colloidal portions in shelf and oceanic waters. Results from this study will help hone future studies to better link the source and fate of iron in the marine environment. A postdoctoral researcher will serve as a principal investigator on the project, providing a unique professional development opportunity. In addition, the project will support the education and research training of one undergraduate student each year, and the researchers will conduct outreach activities to K-12 students and teachers. The colloidal phase of iron may serve as a biological source of stored iron, a primary conveyance for stripping iron into sinking particulate matter (removing it from the pelagic biosphere), or, more likely, a dynamic balance of these roles that fluctuates with the source and character of iron input. The current methods to investigate marine colloidal matter involve operationally defining the bulk colloidal phase using single cutoff filters, a practical decision based on little or no evidence. More problematic, these methods homogenize the colloidal phase, obscuring what almost certainly is a reactivity spectrum of colloidal species tied to their size and compositional character. In this study, the researchers will use Flow Field-Flow Fractionation coupled to Multi-Angle Laser Light Scattering to make measurements of the uniformity or uniqueness of the colloidal size spectrum, and the physical/chemical character of these phases. The findings will have broad implications to the fields of marine ecology and biogeochemistry and, ultimately, to modeling studies of ocean-atmospheric coupling and climate change.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/67961
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Jessica Fitzsimmons.Collaborative Proposal: Assessment of the Colloidal Iron Size Spectrum in Coastal and Oceanic Waters.2015.