Collaborative Research: Alkenone-specific Hydrogen Isotopic Assessment of Surface Water Salinity During the Black Sea's Holocene Evolution

摘要（0601910）合作研究：实验室验证炔酮特异性氢同位素组成作为古盐度测定的可靠定量代理[j]。Prahl（俄勒冈州立大学）和B.N. Popp（夏威夷大学）：了解过去的海洋盐度和温度对于评估基本的海洋学过程（如地表水循环和深水形成）是必不可少的。这些过程是地球表面热量再分配的组成部分，因此也是全球气候变化的动态组成部分。在本项目中，pi建议对一种新的古盐度指标进行校准实验，即由浮游植物Emiliania huxleyi和Isochrysis galbana生物合成的独特生物标志物分子的化合物比氢同位素（D/H）组成。核心假设是，这些生物标志物的D/H基本上是由来源生物生长的水的同位素组成控制的。在这里，我们将分析在不同实验室控制的实验条件下分批培养实验中合成的化合物的D/H值，以评估D/H值随生理生长因子（如养分和光照有效性以及实际盐度变化）以及物种之间的变化程度。该代理的实验室结果随后将用于检查黑海的全新世演化，以确定盐度阈值是否影响了地表水的浮游植物生态，并导致黑海沉积物沉积特征中有充分记录的全新世转变。这些实验的结果将直接整合到课堂教学中，允许将前沿的、热门的信息传递给理科生和非理科生，以及专攻海洋学和地质学的研究生。俄勒冈州立大学荣誉学院的一名本科生将从该项目中受益。夏威夷大学是EPSCoR指定机构，也是联邦政府认可的少数族裔服务机构，因此，来自代表性不足群体的学生可能会从这项研究结果所产生的教育活动中受益。

Abstract (0601910)COLLABORATIVE RESEARCH: Laboratory Validation of Alkenone-Specific Hydrogen Isotopic Composition as a Robust, Quantitative Proxy for Paleosalinity DeterminationF.G. Prahl (Oregon State University) and B.N. Popp (University of Hawaii)Knowledge of past ocean salinity and temperature is essential for assessment of basic oceanographic processes such as surface water circulation and deep water formation. Such processes are integral to the redistribution of heat on the Earths surface and consequently to the dynamics of global climate change. In this project, the PIs propose to conduct calibration experiments on a novel paleosalinity indicator, the compound specific hydrogen isotopic (D/H) composition of unique biomarker molecules that are biosynthesized by the phytoplankton species Emiliania huxleyi and Isochrysis galbana. The central hypothesis is that the D/H of such biomarkers is controlled fundamentally by the isotopic composition of the water in which the source organism grows. Here, the D/H of compounds biosynthesized in batch culture experiments under varying laboratory-controlled experimental conditions will be analyzed in order to evaluate the extent that D/H values can vary as a function of physiological growth factors such as nutrient and light availability and actual salinity change as well as between species. The laboratory results from this proxy will then be used to examine the Holocene evolution of the Black Sea to determine whether a salinity threshold impacted phytoplankton ecology of surface waters and caused the well-documented mid-Holocene shift in the depositional characteristics of Black Sea sediments. Results of these experiments will be integrated directly into classroom teaching, allowing transfer of cutting edge, topical information to undergraduate science and non-science majors and to graduate students specializing in oceanography and geology. An undergraduate student from the Honors College at Oregon State University will benefit educationally from this project. The University of Hawaii is a designated EPSCoR institution and a federally recognized minority-serving institution, thus students from underrepresented groups are likely to be benefit from education activities stemming from the results of this research.