Kalman Filtering and Smoothing of Sediment Records from the Atlantic Ocean over the last 20 KYRS

古气候学是一个快速发展的领域，其记录的准确性和年代学都在不断提高。随着这类记录数量的增加，如何在动力学模型的存在下解释它们的问题就出现了。这项工作由马萨诸塞州伍兹霍尔海洋研究所（Woods Hole Oceanographic Institution）的一名研究人员领导，他们开发了一种反向方法，将长时间的海面温度序列和其他海洋特性（如沉积物岩心分析产生的那些特性）吸收到海洋环流的三维模型中。地质时间尺度上的数据同化带来的计算挑战将通过依赖简化动力学模型和分区卡尔曼滤波平滑器来解决。滤光器将被应用于利用北大西洋过去2万年的沉积物记录来驱动模型。将以与沉积物数据和海洋动力学相一致的方式估计大尺度水文锋面的运动及其伴随的环流变化，从而使各种古海洋学假设得以检验。通过估算北大西洋在过去2万年中随时间变化的状态，该项目将为根据仪器记录假设的海洋环流的持续变化提供一个视角。该项目汇集了一名海洋建模师、一名古海洋学家和两名物理海洋学家，以确保对项目的各个方面采取稳健的方法。这些参与者包括来自法国机构的两名合作者。基金支持伍兹霍尔海洋研究所的一名研究生和一名博士后学者。

Paleoclimatology is a rapidly evolving field, with a sustained production of records with improved accuracy and chronology. As the number of such records increases, the question of how to interpret them in the presence of a dynamical model has emerged. This work, led by a researcher at the Woods Hole Oceanographic Institution in Massachusetts, develops an inverse method for assimilating long time series of sea surface temperature and other oceanic properties, such as those generated from the analysis of sediment cores, into three-dimensional models of ocean circulation. The computational challenge posed by data assimilation over geologic time scales will be addressed by relying on a model with simplified dynamics and on a partitioned Kalman filter & smoother. The filter & smoother will be applied to drive the model with a collection of sediment records over the last 20,000 years from the North Atlantic Ocean. The movements of large-scale hydrographic fronts and the attendant circulation changes over this time interval will be estimated in a manner that is consistent with both sediment data and ocean dynamics, thereby allowing various paleoceanographic hypotheses to be tested. By estimating the time-dependent state of the North Atlantic Ocean over the last 20,000 years, the project will provide a perspective on ongoing changes in ocean circulation that are postulated from instrumental records. This project brings together an ocean modeler, a paleoceanographer, and two physical oceanographers to ensure a robust approach to the various aspects of the project. These participants include two collaborators from French institutions. Funding supports a graduate student and a post-doctoral scholar at the Woods Hole Oceanographic Institution.