Free Drifting Icebergs: Influence of Floating Islands on Pelagic Ecosystems in the Weddell Sea.

自由漂流冰山：漂浮岛屿对威德尔海中上层生态系统的影响。

• 批准号: 0529815
• 负责人: Kenneth Smith
• 金额: $ 19.95万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2006-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0529815&HistoricalAwards=false
• 关键词: Free; Drifting; Icebergs; Influence; Floating

This project seeks to examine the importance of icebergs to the pelagic ecosystem of the North-West Weddell Sea. Atmospheric warming has been associated with retreating glaciers and the increasing prevalence of icebergs in the Southern Ocean over the last decade. The highest concentration of icebergs occurs in the NW Weddell Sea, where they drift in a clockwise pattern to the northeast, following the contours of the Antarctic Peninsula through an area dubbed "Iceberg Alley". Little is known about the impact of free-drifting icebergs on the pelagic ecosystem of the Weddell Sea or on the Southern Ocean as a whole. It is hypothesized that as drifting islands, icebergs of small to intermediate size ( 10 km in largest dimension) impart unique physical, chemical and biological characteristics to the surrounding water. Three general questions will be asked to address this hypothesis: 1) What are the dynamics (approximate size, abundance and spatial distribution) of free-drifting icebergs on temporal scales of days to months, based on correlation of field measurements with imagery derived from satellite sensors? 2) What is the relationship between the size of free-drifting icebergs and the structure of the associated pelagic communities? 3) What is the estimated combined impact of free-drifting icebergs in the NW Weddell Sea on the biological characteristics of the pelagic zone? This interdisciplinary study will use standard oceanographic sampling coupled with unique methodology for staging shipboard data from all types of sensors and survey methods to determine the sphere of influence for a diverse set of biological factors as a function of iceberg size. The exploratory research proposed here will provide critical data on the effects of atmospheric warming in the Antarctic Peninsula region. The recent prevalence of free drifting icebergs in the Southern Ocean should have a pronounced enrichment effect on the surrounding pelagic ecosystem, altering community dynamics. Enhanced primary production associated with these icebergs could influence the global carbon cycle since the Southern Ocean is considered a major sink for excess CO2 from the atmosphere. The proposed research will include an innovative education component through the Ocean Exploration Center (OEC), whose focus is to provide a comprehensive view of the oceans, intelligible to non-scientists and researchers alike, with direct access to state-of-the-art databases and selected websites. The OEC will allow users to access content which has been classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. The results from this iceberg project will be incorporated into the Antarctic Research division of the OEC, providing databases documenting the impact of free-drifting icebergs on the surrounding pelagic ecosystem. These data then will be extrapolated to evaluate the impact of icebergs on the ecosystem of the Weddell Sea. Graduate students, undergraduates, teachers and volunteers are an important part of the proposed field and laboratory work.

该项目旨在研究冰山对威德尔海西北部远洋生态系统的重要性。 过去十年来，大气变暖与冰川退缩和南大洋冰山日益增多有关。 最密集的冰山出现在西北部的威德尔海，在那里它们以顺时针方向向东北方向漂移，沿着南极半岛的轮廓穿过一个被称为“冰山巷”的区域。 人们对自由漂流的冰山对威德尔海或整个南大洋的远洋生态系统的影响知之甚少。 据推测，作为漂流的岛屿，小到中等大小的冰山（最大尺寸为10公里）给周围的水带来了独特的物理、化学和生物特性。 将提出三个一般性问题来解决这一假设：1）根据实地测量与卫星传感器图像的相关性，自由漂流冰山在几天到几个月的时间尺度上的动态（大致大小、丰度和空间分布）是什么？ 2)自由漂流的冰山的大小与相关的远洋群落的结构之间有什么关系？ 3)据估计，威德尔海西北部自由漂流的冰山对水层生物特征的综合影响是什么？ 这项跨学科的研究将使用标准的海洋学取样，加上独特的方法，从所有类型的传感器和调查方法中收集船上数据，以确定作为冰山大小函数的各种生物因素的影响范围。这里提议的探索性研究将提供关于大气变暖对南极半岛地区影响的关键数据。最近在南大洋自由漂流的冰山的流行应该对周围的远洋生态系统产生明显的富集效应，改变群落动态。 与这些冰山相关的初级生产的增加可能会影响全球碳循环，因为南大洋被认为是大气中过量二氧化碳的主要汇。拟议的研究将包括通过海洋探索中心进行的创新教育部分，其重点是提供对海洋的全面了解，使非科学家和研究人员都能理解，并能直接进入最先进的数据库和选定的网站。 OEC将允许用户访问已分类为四个级别之一的内容：入门（K-6级），学生（6-12级），大学和研究。 这个冰山项目的结果将被纳入OEC的南极研究部门，提供记录自由漂流冰山对周围远洋生态系统影响的数据库。 然后将这些数据外推，以评估冰山对威德尔海生态系统的影响。 研究生、本科生、教师和志愿者是拟议的实地和实验室工作的重要组成部分。