Collaborative Research: Controls on Alkenone Temperature Estimates in Subtropical and Subpolar Waters

合作研究：副热带和副极地水域烯酮温度估计的控制

• 批准号: 0726048
• 负责人: Elisabeth Sikes
• 金额: $ 32.37万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0726048&HistoricalAwards=false
• 关键词: Collaborative; Research; Controls; Alkenone; Temperature

The subtropical front (STF) is the northern boundary of the Southern Ocean, separating oligotrophic, warm subtropical surface waters north of the STF from cooler, nutrient-rich, subpolar waters to the south. East of New Zealand, the STF is bathymetrically anchored to the Chatham Rise, a 1000 km long submerged continental plateau. The National Institute of Water and Atmospheric Research (NIWA), New Zealand, maintains two sediment trap arrays only 200 km apart on the Chatham Rise. The traps, although closely spaced, sit just out of the axis of the STF and thus allow comparison of subtropical and subpolar waters under similar environmental conditions such as weather and light levels over the annual cycle without the complication of frontal migrations. In this project, researchers at Rutgers University and the University of Hawaii will examine at these sites the processes involved in the formation of the proxies on which paleo-sea surface temperatures (SST) records are based and resolve the issue of differential seasonality between the organisms which are arguably two of the most important paleotemperature estimators now in use (e.g. U37 K ' accuracy, foraminiferal ä18O values). The principle hypotheses to be tested are:1. Episodic delivery of alkenones and foraminifera exported from the surface mixed layer are the underlying cause of differences between alkenone and foraminiferal temperature reconstructions.2. Nutrient depletion in subtropical waters during summer months and subsurface production during prolonged winter darkness in subpolar waters are important environmental influences controlling the accuracy of U 37 K ' SST reconstructions.Efforts in this work primarily and actively address the broader impact criteria of enhancing infrastructure for research. Collaborations among United States, New Zealand, and European scientists represent a significant investment in outreach with international colleagues by the US PI?s. The combined results will enhance the research of all members by disseminating shared data widely and serve to stimulate future partnerships. Additionally, training of students who will take central roles in this research addresses advancing training and learning. Better quantification of SST records will benefit paleoclimatic reconstructions and thus have societal benefits.

副热带锋 (STF) 是南大洋的北部边界，将 STF 北部的贫营养、温暖的副热带表层水域与新西兰东部南部较冷、营养丰富的副极地水域分开，STF 在测深上固定在该水域。查塔姆海隆是一个 1000 公里长的水下大陆高原，新西兰国家水和大气研究所 (NIWA) 仅维护着两个沉积物捕集器阵列。查塔姆隆起上的陷阱虽然间隔很近，但位于 STF 轴线之外，因此可以在类似的环境条件（例如年度周期的天气和光照水平）下比较亚热带和亚极地水域，而不会出现复杂情况。在这个项目中，罗格斯大学和夏威夷大学的研究人员将在这些地点研究古海表面温度（SST）记录所依据的代理形成过程。解决目前使用的两个最重要的古温度估算器中存在争议的生物体之间的季节性差异问题（例如 U37 K ' 精度、有孔虫 ä18O 值）。要测试的主要假设是： 1．地表混合层输出的温度是造成亚热带地区烯酮和有孔虫温度重建差异的根本原因。2．夏季月份的水域和次极地水域冬季长时间黑暗期间的地下生产是控制 U 37 K ' SST 重建准确性的重要环境影响。这项工作的努力主要是积极解决加强联合国之间的研究基础设施的更广泛的影响标准。美国、新西兰和欧洲科学家在与国际同行的推广方面投入了大量资金，综合结果将通过广泛传播共享数据来加强所有成员的研究，并有助于促进未来的合作伙伴关系。将会的学生在这项研究中发挥核心作用，更好地量化海表温度记录将有利于古气候重建，从而产生社会效益。