Further Calibration of Long-Chain Alkenones for Paleoceanographic Study

长链烯烃被广泛认为是评估海洋地表水古温度和一定程度上古生产力的有前途的方法。由于对产生这些生物标记物的浮游植物物种的生态学和产生这些生物标记物的浮游植物物种的生态学以及产生这些生物标记物的过程的无知，我们准确解释海洋沉积物岩心中烯酮的地层记录的完整古海洋学含义的能力目前受到限制它们在沉积记录中的保存。这项研究将提高我们从沉积记录中提取真实的古海洋学信息的能力。该项目将综合实验室浮游植物培养和实地颗粒样品的分析结果。现场样品包括从海洋表层水域收集的精选悬浮颗粒材料，通过沉积物捕集器按时间序列收集的垂直运输颗粒材料，以及通过在加利福尼亚北部东西向样带的三个地点取心收集的底层沉积物。提出的工作的两个主要目标是澄清：1)产生烯酮的浮游植物在光带中的位置随季节变化；这些生物在一年中的生产时间，以及由这些因素在下伏沉积物中测量的烯酮不饱和模式记录的地表水温度，以及2)下伏岩心中烯酮浓度的记录如何与原体生产力的相对变化以及可能与上覆层中总初级生产力的变化相关联水随时间流逝。

Long-chain alkenones are now widely recognized as promising for the assessment of paleotemperature and to some extent paleoproductivity in surface waters of the ocean. Ourability to interpret accurately the complete paleoceanographic implications of stratigraphic records for the alkenones inmarine sediment cores is currently limited by an ignorance of the ecology of the phytoplankton species that produce these biomarkers and of the ecology of the phytoplankton species that produce these biomarkers and of the processes responsible for their preservation in the sedimentary record. This research will advance our ability to extract realistice paleoceanographic information from the sedimentary record for the alkenonoes. The project willintegrate results from analyses of laboratory phytoplankton cultures and particulate samples from the field. The field samples include select sets of suspended particulate materials collected from ocean surface waters, vertically transported particulate materials collected in time series by sediment traps and underlying sediments collected by coring at three locations along an east-west transect off northern California. The two major goals of the proposed work are to clarify 1) where alkenone-producing phytoplankton reside withing the euphotic zone as a function of season, when these organisms are productive during the year and what surface water temperature is recorded by alkenone unsaturation patterns measured in underlying sediments as a consequence of these factors and 2) how the downcore record for alkenone concentration relates torelative changes in prymnesiophyte productivity and perhaps total primary productivity in overlying waters with time.