Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula

合作研究：阐明波里纳斯和南极西部半岛生产力的环境控制

基本信息

批准号：
1643652
负责人：
Eileen Hofmann
金额：
$ 25.2万
依托单位：
Old Dominion University Research Foundation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-15 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643652&HistoricalAwards=false
关键词：
Collaborative Research Elucidating Environmental Controls

项目摘要

Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for 50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.

南极周围的沿海水域代表了地球上生物学上最丰富，最未触及的生态系统。在很大程度上，这种生物学丰富性集中在南极大陆附近宽敞的海冰（这些开口称为Polynyas）的众多开口处。这些波利尼亚代表了增强生产的区域，称为热点，并支持南大洋中最高的动物密度。他们中的许多人也位于庞大的南极冰盖的浮动延伸旁边，并且在夏季，每年都会获得大量的融水径流。但是，对于使这些生态系统如此生物生产的特定过程知之甚少。在目前已知的46个南极沿海Polynyas中，仅详细研究了少数。该项目将开发Ross Sea Polynya，Amundsen Polynya和Pine Island Polynya的生态系统模型；三个最有生产力的南极沿海波利尼亚人。主要目标是使用这些模型更好地了解这些过程中的基本物理，化学和生物相互作用过程以及使这些系统在某些方面（例如大小和生产力）在当今环境中如此生物学上有效但有所不同的差异。还将扩展建模工作，以评估这些生态系统在过去如何运作，以及它们在不同的物理和化学和气候环境下如何改变。该项目将通过斯坦福大学的地球科学与工程学计划（Surge）计划的夏季本科研究来推进代表性不足的少数民族的教育。 Surge将为本科生提供在斯坦福大学工程和地球科学的指导研究经验的机会。 Old Dominion University还将为当地公立和私立学校采用外展计划，以及一个支持Boy Scout Oceanshophing优异徽章计划的持续计划，以创造外展和教育影响。波利尼亚（海冰包围的开放水域）是极地生态系统的生产力不成比例的，但对其高生产率的控制尚不清楚。该项目将提供对控制Polynyas内浮游植物丰度和生产力的物理和化学过程的定量评估，不同的Polynyas的不同以及Polynyas将来如何变化。特别令人感兴趣的是波利尼亚岛内的过程之间的相互作用以及附近冰盖的夏季融化，包括Thwaites和Pine Island冰川。在这项拟议的研究中，我们将开发一系列全面的，高分辨率的物理生物学模型，并将其用于三个主要但多样化的南极Polynyas。这些Polynyas，Ross Sea Polynya，Amundsen Polynya和Pine Island Polynya，占南极总生产总量的50％。要解决的研究问题是：1）哪些环境因素对南极洲围绕Polynyas的初级生产最大的控制？ 2）什么是导致对南极大陆架周围波利尼亚氏菌区溶解铁（DFE）供应的异质性（DFE）的异质性？这对本地生产率有什么影响？ 3）由于气候引起的物理学的变化（风，海冰，冰架基础熔体，跨架子交换，分层和垂直混合），在接下来的几十年中，DFE供应向舒适区供应的可能发生了什么可能发生的变化？罗斯海，阿蒙森和派恩岛多尼亚是南极洲中最鲜为采样的多尼亚斯，促进了模型的参数化和验证。此外，这些Polynyas的大小，位置，海冰动力学，与融化冰架的关系以及与大陆架破裂的距离之间的差异很大，使其成为理想的案例研究。为了进行比较，西南盘半岛（WAP）是一种生产性的大陆架，其中Polynyas是生物生产的相对较小的贡献者，也将被建模。调查南极沿海水域中不同类型的特定过程将更好地了解这些重要的生物绿洲如何发挥作用以及它们如何在不同的环境条件下变化。