Collaborative Research: Modeling and synthesis study of a natural iron fertilization site in the Southern Drake Passage

海洋通过生物泵将固定碳输出到深海，在封存二氧化碳方面发挥着关键作用。在全球变暖的背景下，迫切需要了解南大洋碳出口的系统性，因为该区域对气候变化非常敏感，这已经表现为气温的显著上升。大量研究表明，铁的供应是南大洋浮游植物生物量和生产力的主要控制因素。2004年2-3月和2006年7-8月历次航次的观测结果揭示了富铁陆架水域到德雷克海峡南部富铁高营养低叶绿体(HNLC)南极绕极流表层水(ASW)的主要自然铁营养作用，产生了一系列浮游植物水华。剩下的问题包括：在不同的HNLC ACC区域，天然铁是如何通过小-中-大尺度的水平-垂直输送和混合输送到真光带的？浮游生物群落结构是如何对自然添加的铁作出反应的，铁的形态形成如何对生物地球化学过程做出反应，以及铁是如何循环利用来决定浮游植物水华的寿命的？POC的输出是如何作为上升流-混合、铁的添加-循环和细菌-浮游生物结构的函数而演变的？这项综合提案将使用一个独特的数据集，结合2004至2006年间收集的多年物理、铁和生物地球化学数据，这些数据来自NSF资助的2次铁肥试验邮轮和3次南极海洋生物资源(AMLR)邮轮，这些邮轮位于德雷克海峡南部和斯科舍海西南部，通过与AMLR计划和美国南大洋GLOBEC项目的科学家合作，解决了这些基本问题。所有参与这项研究的研究人员都致力于研究生和本科生的指导，以及博士后研究人员的指导。每个P.I.将在我们的课堂、习题集和小组项目中包含提议的合成的关键元素。该项目包括支持在伍兹霍尔海洋研究所举办一次为期4-5天的天然铁肥国际讲习班。研讨会将包括英国、法国和德国进行过天然铁肥实验的科学家，以及计划进行天然铁肥实验的韩国和中国。特别鼓励研究生和博士后学者参与。研究结果将发表在《深海研究II》特刊上。

The ocean plays a critical role in sequestering CO2 by exporting fixed carbon to the deep ocean through the biological pump. There is a pressing need to understand the systematics of carbon export in the Southern Ocean in the context of global warming because of the sensitivity of this region to climate change, already manifested as significant temperature increases. Numerous studies have indicated that Fe supply is a primary control on phytoplankton biomass and productivity in the Southern Ocean. The results from previous cruises in Feb-Mar 2004 and Jul-Aug 2006 have revealed the major natural Fe fertilization from Fe-rich shelf waters to the Fe-limited high nutrient low chlorophyll (HNLC) Antarctic Circumpolar Current Surface Water (ASW) in the southern Drake Passage, producing a series of phytoplankton blooms. Remaining questions include: How is natural Fe transported to the euphotic zone through small-meso-large scale horizontal-vertical transport and mixing in different HNLC ACC areas? How does plankton community structure evolve in response to a natural Fe addition, how does Fe speciation respond to biogeochemical processes, and how is Fe recycled to determine the longevity of phytoplankton blooms? How does the export of POC evolve as a function of upwelling-mixing, Fe addition-recycling and bacteria-plankton structure? This synthesis proposal will address these fundamental questions using a unique dataset combining multiyear physical, Fe and biogeochemical data collected between 2004 and 2006 from 2 NSF-funded Fe fertilization experiment cruises and 3 Antarctic Marine Living Resource (AMLR) cruises in the southern Drake Passage and southwestern Scotia Sea through collaboration with scientists in the AMLR program and US Southern Ocean GLOBEC projects. All investigators involved in this study are engaged in graduate and undergraduate instruction, and mentoring of postdoctoral researchers. Each P.I. will incorporate key elements of the proposed syntheses in our lectures, problem sets and group projects. The project includes support to convene a 4-5 day international workshop on natural Fe fertilization at Woods Hole Oceanographic Institution. The workshop will include scientists from United Kingdom, France and Germany who have conducted natural Fe fertilization experiments, and Korea and China who are planning to conduct natural Fe fertilization experiments. The participation of graduate students and postdoctoral scholars will be especially encouraged. The results will be published in a Deep-Sea Research II special issue.