Factors Controlling the Abundance of 13C in Algal and Sedimentary Biomarkers from the Amundsen and Bellingshausen Seas, Antarctica

9418833 Hayes本项目研究的是对海底泥和沉积物岩心有机碎屑中编码的古海洋学信息进行解释的一般性问题，即有机分子的沉积碳氮同位素与当代海洋学条件之间的关系。具体地说，将通过分析1994年初从贝林豪森海和阿蒙森海取得的海水和沉积物样本来审查各种藻类、其生长条件和有机和无机营养物浓度之间的联系。将特别强调特定种类藻类的碳-13含量与水柱中硝酸盐、磷酸盐和溶解二氧化碳的浓度之间的关系。南极洲周围的海洋在这方面很重要，因为它们在调节全球气候模式方面具有假定的重要性。在全球范围内，沉积碳-13的测量通常是在生物地球化学循环研究的背景下进行的。然而，碳-13同位素变率与特定过程或现象的关联，在一个地区似乎在统计上是有效的，通常在其他地区并不有效，这意味着小规模关系不能简单地推广到大规模关系。分析这一特定数据集的优势在于，在巡航中获得了大量辅助信息，因此，除了阐明温度对潜在生化过程的影响，并明确界定南极过程之外，还存在将现有但不太完整的数据集联系在一起的强大潜力。＊＊＊

9418833 Hayes This project deals with the general question of the interpretation of paleoceanographic information that is encoded in the organic debris of sea floor muds and sediment cores, that is, what is the relationship between the sedimentary carbon and nitrogen isotopes of organic molecules and contemporary oceanographic conditions. Specifically the linkages among types of algae, conditions of their growth, and the concentration of organic and inorganic nutrients will be examined through the analysis of seawater and sediment samples obtained from the Bellinghausen and Amundsen Seas in early 1994. Particular emphasis will be placed on the relationship between the Carbon-13 content of specific species of algae, and the concentrations of nitrate, phosphate, and dissolved carbon dioxide in the water column. The seas surrounding Antarctica are important in this context because of their presumptive importance in regulating global climate patterns. On the global scale, measurements of sedimentary Carbon-13 are made routinely in the context of biogeochemical cycling studies. However the association of Carbon-13 isotopic variability with particular processes or phenomena that appear statistically valid in one region are generally found not to be valid in others, implying that small-scale relationships cannot simply be generalized to large-scale relationships. The advantage of analyzing this particular data set lies in the fact that a large body of ancillary information was obtained on the cruise, and therefore the strong potential exists to tie together existing, but less complete, data sets in addition to elucidating temperature effects on underlying biochemical processes, and defining specifically antarctic processes. ***