Holocene paleoceanography and climate variability in the Western Arctic Ocean

北冰洋西部的全新世古海洋学和气候变化

• 批准号: 418199-2013
• 负责人: MonteroSerrano, JeanCarlos
• 金额: $ 2.04万
• 依托单位: Université du Québec à Rimouski
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=573533
• 关键词: Holocene; paleoceanography; climate; variability; Western

The Arctic Ocean is a sensitive responder to climate changes as well as active driver of global and regional atmospheric and oceanic circulation patterns. In order to document long-term natural climate cycles and predict future climate trends for the Arctic Ocean, one needs to reconstruct the oceanic dynamics locked in sedimentary records in which hydrologic and oceanographic responses to climatic changes are represented by the variability of sedimentary and geochemical tracers. Among these tracers, the clay minerals (e.g., illite, kaolinite, chlorite and smectite), radiogenic isotopes [e.g., neodymium (Nd), lead (Pb) and strontium (Sr)] and sedimentary protactinium-231/thorium-230 (231Pa/230Th) records from marine sediments are useful tools for paleoceanographic and paleoclimatic reconstructions. Under this context, the overall objective of this research program is to use a powerful multi-proxy approach combining clay mineral composition, elemental geochemistry, radiogenic isotope compositions (Nd, Pb and Sr) in both the clay-size fraction and authigenic (seawater-derived) ferromanganese coatings, and sedimentary 231Pa/230Th ratios from identical sediment core samples from the continental margins of the Canadian Beaufort and Chukchi seas, in order to document Holocene changes in continental inputs, deep-Arctic circulation and current transport related to climate change. Hence, because Holocene sedimentation rates in the continental margins of the Canadian Beaufort and Chukchi seas reach up to 120 cm/ka, this innovative research program will offer a unique opportunity to reconstruct the natural evolution and variability of climatic and oceanographic conditions in the Western Arctic Ocean during the last 10,000 years at decadal to millennial timescales. These results not only will help to significantly advance our understanding on the future Arctic climate and oceanographic dynamics, but will also provide high temporal resolution data that will help to better constrain the regional climate models. Finally, this unique pool of mineralogical and geochemical tools will also offer a dynamic training environment for highly qualified personnel with access to expertise in different fields of marine geology and geochemistry.

北冰洋是气候变化的敏感反应器，也是全球和区域大气和海洋环流模式的积极推动者。为了记录长期的自然气候循环和预测北冰洋未来的气候趋势，人们需要重建海洋动力学锁定在沉积记录，其中水文和海洋学对气候变化的反应是由沉积和地球化学示踪剂的变化。在这些示踪剂中，粘土矿物（例如，伊利石、高岭石、蒙脱石和蒙脱石），放射性同位素[例如，钕（Nd）、铅（Pb）和锶（Sr）]和沉积物中的~（231）P_a/~（230）Th记录是恢复古海洋和古气候的有用工具。在此背景下，本研究计划的总体目标是使用一种强大的多代用指标方法，结合粘土矿物组成，元素地球化学，放射性同位素组成，（Nd，Pb，Sr）在粘土粒级和自生的（海水衍生的）锰铁涂层，和来自加拿大博福特海和楚科奇海大陆边缘相同沉积物岩心样品的沉积231 Pa/230 Th比值，为了记录全新世大陆输入、北极深环流和与气候变化有关的海流输运的变化。因此，由于加拿大博福特和楚科奇海大陆边缘的全新世沉积速率达到120厘米/ka，这一创新的研究计划将提供一个独特的机会，重建在过去的10,000年在十年到千年的时间尺度在北冰洋西部的气候和海洋条件的自然演变和变化。这些结果不仅将有助于大大推进我们对未来北极气候和海洋动力学的理解，而且还将提供高时间分辨率的数据，这将有助于更好地约束区域气候模式。最后，这一独特的矿物学和地球化学工具库还将为获得海洋地质学和地球化学不同领域专门知识的高素质人员提供一个动态的培训环境。