Fe isotope composition of seawater as a tracer for marine Fe sources and biogeochemical cycles

铁的分布和化学形态对海洋生物有着深远的影响。在世界上大约20%的海洋中，初级生产力是有限的，因为浮游植物不能获得足够的铁来满足它们的生理需要。因此，海水铁浓度的微小变化会影响浮游植物的生长，影响生态系统的生产力，以及海洋中碳的固存。尽管铁元素很重要，但关于海洋铁循环仍存在许多问题。出于这个原因，加州理工学院的科学家将确定圣佩德罗盆地和大西洋的溶解和颗粒样品中的铁同位素分异，以提供对这种金属的生物地球化学循环的新见解。具体来说，研究人员计划解决以下问题：(1)世界海洋中溶解铁的来源是什么？(2)海洋颗粒铁通过哪些过程成为生物可利用的？(3)溶解的del56Fe是否是铁生物循环的示踪剂？在教育影响方面，这项研究的资金将支持一名研究生和一名博士后研究员。

The distribution and chemical form of iron (Fe) has a profound impact on marine life. In approximately 20% of the world's ocean, primary productivity is limited because phytoplankton cannot obtain enough Fe to satisfy their physiological needs. Therefore, small changes in seawater Fe concentrations can impact the growth of phytoplankton and affect the productivity of ecosystems, as well as the sequestration of carbon in the ocean. Despite the importance of Fe, many questions remain about the marine Fe cycle. For this reason, scientists from California Institute of Technology would determine the Fe isotopic fractionation in dissolved and particulate samples from San Pedro Basin and the Atlantic Ocean to provide new insights into the biogeochemical cycle of this metal. Specifically, the researchers plan to address the following questions: (1) What is the source of dissolved Fe in the world's oceans?; (2) Via what processes does marine particulate Fe become bioavailable?; and (3) Is dissolved del56Fe a tracer of biological cycling of Fe?In regard to educational impact, funding from this research would support a graduate student and a postdoctoral researcher.