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

副热带锋（STF）是南大洋的北部边界，将副热带锋以北的少营养、温暖的副热带表层水与南部较冷、营养丰富的亚极地水域分开。在新西兰东部，STF在水深上锚定在查塔姆隆起，这是一个长达1000公里的水下大陆高原。新西兰国家水与大气研究所（NIWA）在查塔姆隆起维护着两个相距仅200公里的沉积物捕集器阵列。这些陷阱虽然间隔很近，但正好位于STF的轴线之外，因此可以在类似的环境条件下（如天气和光照水平）比较亚热带和亚极地水域，而不会出现锋面迁移的复杂性。在这个项目中，罗格斯大学（Rutgers University）和夏威夷大学（University of Hawaii）的研究人员将在这些地点检查古海表温度（SST）记录所依据的代用品的形成过程，并解决生物之间季节性差异的问题，这些生物是目前使用的两个最重要的古温度估计器（例如U37 K的准确性，有孔虫的18O值）。要检验的主要假设有：1。从表面混合层输出的烯酮和有孔虫的间歇性传递是造成烯酮和有孔虫温度重建差异的根本原因。夏季亚热带水域的养分耗竭和亚极地水域冬季长时间黑暗期间的地下生产是控制u37k海温重建精度的重要环境影响因素。这项工作主要和积极地解决了加强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之间的合作代表了美国PI在与国际同行接触方面的重大投资。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伙伴关系。此外，培训将在本研究中扮演核心角色的学生，以促进培训和学习。更好地量化海温记录将有利于古气候重建，从而具有社会效益。

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 '18O 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.