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：实验室验证特定于烯酮的氢同位素组成作为确定古盐度的可靠的定量指标。了解过去的海洋盐度和温度对于评估基本的海洋过程，如地表水循环和深水形成至关重要。这些过程对于地球表面热量的重新分配以及全球气候变化的动态都是不可或缺的。在这个项目中，PIS建议对一种新的古盐度指示器进行校准实验，即由浮游植物物种Emily huxleyi和Isochrysis galbana生物合成的独特生物标志物分子的化合物特定氢同位素(D/H)组成。中心假设是，这类生物标志物的D/H从根本上受来源有机体生长的水的同位素组成控制。在这里，将分析在不同实验室控制的实验条件下在分批培养实验中生物合成的化合物的D/H值，以评估D/H值作为生理生长因素的函数的程度，例如养分和光的有效性以及实际盐度的变化以及物种之间的变化。然后，该代理的实验室结果将被用来研究黑海的全新世演化，以确定盐度阈值是否影响了地表水的浮游植物生态，并导致了有据可查的中全新世黑海沉积物沉积特征的转变。这些实验的结果将直接整合到课堂教学中，允许向本科生和非理科专业的本科生以及海洋学和地质学专业的研究生传授前沿的专题信息。俄勒冈州立大学荣誉学院的一名本科生将从这个项目中受益。夏威夷大学是指定的EPSCoR机构和联邦承认的少数群体服务机构，因此，来自代表性不足群体的学生很可能从这项研究结果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.