An Investigation of Photosynthetic Carbon Isotope Fractionation in the Ocean

摘要多年来，人们一直在研究现代海洋和沉积记录中海洋有机质中有机碳的同位素组成。碳-13/碳-12比值的变化被解释为温度变化（或差异）、海水中溶解的二氧化碳量、浮游植物的生长速度和生产力以及其他可能性。这种现象不仅是当今海洋化学的一个主要特征，而且还可能有助于通过对沉积记录的同位素研究来了解全球二氧化碳的历史变化。在这项研究中，首席研究员将进行一系列的实验室实验和实地比较，以测试浮游植物吸收碳同位素分馏的数学模型的强度。他将与德国不来梅港阿尔弗雷德·韦格纳研究所和蒙特利湾水族馆研究所的同事合作，研究几种过程对浮游植物碳同位素分异的影响。如果成功，这项工作可能会为理解当今海洋的碳同位素化学提供一种新的预测工具，并可能通过分析海洋沉积物岩心为理解古气候提供一把钥匙。

OCE-9618626 ABSTRACT OCE-9618626 The isotopic composition of organic carbon in marine organic matter in the modern ocean and in the sedimentary record has been an object of study for a number of years. Variations in the carbon-13/carbon-12 ratio have variously been interpreted as arising from changes (or differences) in temperature, the amount of dissolved carbon dioxide in seawater, growth rate and productivity of phytoplankton, among other possibilities. The phenomenon is not only a major feature of present-day ocean chemistry but, moreover, may be of use for understanding historical variations in global carbon dioxide through isotopic studies of the sedimentary record. In this study the principal investigator will conduct a series of laboratory experiments and field comparisons to test the strength of a mathematical model for carbon isotope fractionation resulting from uptake by phytoplankton. In collaboration with colleagues at the Alfred Wegener Institut in Bremerhaven, Germany, and the Monterey Bay Aquarium Research Institute, he will study the effects of several processes on carbon isotope fractionation by phytoplankton species. If successful, this work could lead to a new predictive tool for understanding the carbon isotope chemistry of the present-day ocean and perhaps provide a key to understanding paleoclimate through analysis of marine sediment cores.