Collaborative Research: Investigating Holocene Paleoclimate In TheWestern Arctic Ocean Using Very High-Resolution Marine Records Off Alaska

合作研究：利用阿拉斯加近海的高分辨率海洋记录调查北冰洋西部的全新世古气候

• 批准号: 0612493
• 负责人: Dennis Darby
• 金额: $ 42.37万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0612493&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; Holocene; Paleoclimate

ABSTRACTDarbyOPP-0612493BrachfieldOPP-: 0612365 PolyakOPP-0612384OrtizOPP-0612473Intellectual Merit: Understanding how the climate system functions and how it might change, especially in the climate-sensitive Arctic Ocean, is of paramount importance and could be achieved through high-resolution paleo-records. Until the Healy-Oden Trans-Arctic Expedition (HOTRAX'05), such records in the Arctic Ocean were very rare. HOTRAX not only recovered several high-resolution records from the Alaskan margin, but also plankton tows for isotopic calibration of foraminifer, and samples of porewater collected under hermetic conditions for calibration of important proxies such as pyrite and monosulfides as potential indicators of paleoproductivity. Many proxies will be measured in the research including: sediment reflectivity, biogenic components (foraminifer, dinocysts, etc.), nutrients, stable isotopes and cadmium/calcium and magnesium/calcium in foraminiferal tests, and iron oxide fingerprinting of ice rafted debris for sea ice sources and drift patterns. Age models and detailed core correlation will be of primary concern initially and involve several approaches including AMS carbon-14, paleomagnetics, and lead-210. The objective will be to establish paleoclimate records for the Holocene for the HOTRAX cores along the continental shelf margin north of Alaska in a critical zone for the confluence and impact of different water masses. These cores should be impacted by many of the important influxes that might affect or record climate change in the western Arctic Ocean, such as the Mackenzie River and other drainage systems, the Bering Strait influx of Pacific waters, and the sub-surface influx of North Atlantic Intermediate water. These cores are ideal for recording sea ice input events from Russian Shelves into the Beaufort Gyre presumably in response to fluctuations in the Arctic Oscillation. Therefore, several proxies will be employed to measure the important environmental and climatic changes that should be recorded in these very high resolution HOTRAX cores. Broader Impacts: This research interfaces and fulfills many aspects of existing research initiatives such as the Study of Arctic environmental change (SEARCH), western Arctic Shelf-Basin Interactions (SBI), and paleoclimate component of the International Committee for Arctic Paleo Projects (ICARP) and its International Polar Year (IPY) affiliation. In addition, the results of this research could have important implications for residents of the north slope of Alaska with the focus on freshwater inputs and Russian ice to the waters offshore. Several graduate and undergraduate students will be involved. Many of the findings will be incorporated into courses taught by the investigators and talks to professional and community groups. More significantly, there will be opportunities for underrepresented minority students to participate and contribute to the proposed research through Old Dominion University's (ODU) Minority Undergraduate Scholarship and Training REU program (NSF-funded) and the joint ODU-Hampton University-Virginia Institute of Marine Sciences' Hall-Bonner Program for Minority Doctoral Scholars in Ocean Sciences (a NSF-funded Diversity in Geosciences grant). Collaboration with Teachers and Researchers Exploring and Collaborating (TREC) earth science teachers, begun on the HOTRAX cruise, will continue as part of this project with the development of small research exercises for the students that will be part of a website for use by similar teachers world-wide.

学术价值：理解气候系统的功能及其可能的变化，特别是在气候敏感的北冰洋，是至关重要的，可以通过高分辨率的古记录来实现。在希利-奥登跨北极探险（HOTRAX'05）之前，这样的北冰洋记录非常罕见。HOTRAX不仅恢复了阿拉斯加边缘的高分辨率记录，还恢复了浮游生物拖带，用于有孔虫的同位素校准，以及在密封条件下收集的孔隙水样本，用于校准重要的代用品，如黄铁矿和单硫化物，作为古生产力的潜在指标。研究中将测量许多代用物，包括：沉积物反射率、生物成分（有孔虫、囊藻等）、营养物质、稳定同位素和有孔虫试验中的镉/钙和镁/钙，以及海冰来源和漂移模式的浮冰碎片的氧化铁指纹。年龄模型和详细的岩心对比将是最初的主要关注点，包括AMS碳-14、古磁学和铅-210等几种方法。目的是在阿拉斯加北部大陆架边缘的一个不同水团汇合和影响的关键地带，为HOTRAX岩芯建立全新世的古气候记录。这些核心应该受到许多可能影响或记录北冰洋西部气候变化的重要水流的影响，例如麦肯齐河和其他排水系统，白令海峡流入的太平洋水，以及北大西洋中层水的地下流入。这些冰芯是记录从俄罗斯冰架到波弗特环流的海冰输入事件的理想工具，这可能是对北极涛动波动的反应。因此，将采用几种代用物来测量这些高分辨率HOTRAX岩心中应该记录的重要环境和气候变化。更广泛的影响：本研究结合并实现了现有研究计划的许多方面，如北极环境变化研究（SEARCH）、北极西部陆架-盆地相互作用（SBI）、国际北极古项目委员会（ICARP）的古气候组成部分及其国际极地年（IPY）的关联。此外，这项研究的结果可能对阿拉斯加北坡的居民具有重要意义，重点是淡水输入和俄罗斯冰到近海水域。一些研究生和本科生将参与其中。许多调查结果将被纳入调查人员教授的课程，并与专业和社区团体进行交谈。更重要的是，代表性不足的少数民族学生将有机会通过老道明大学（ODU）的少数民族本科奖学金和培训REU计划（美国国家科学基金会资助）以及奥德明大学-汉普顿大学-弗吉尼亚海洋科学研究所的海洋科学少数民族博士学者霍尔-邦纳计划（美国国家科学基金会资助的地球科学多样性资助）参与并为拟议的研究做出贡献。与教师和研究人员的合作探索与合作（TREC）地球科学教师的合作始于HOTRAX巡航，将继续作为该项目的一部分，为学生开发小型研究练习，这些练习将成为一个网站的一部分，供世界各地的类似教师使用。