High-resolution multiproxy reconstruction of extratropical North Atlantic climate dynamics during the last millennium

高分辨率的时空海洋代理记录，特别是来自温带环境的记录，对于理解地球系统内运行的强迫和反馈机制至关重要。然而，到目前为止，即使是最好的分辨率记录，来自冰岛北部近海的沉积物岩心，也只能提供2-5年的分辨率，并且强烈偏向夏季。这些数据不足以确定状态变化发生的速度或提供时空气候动力学的细节。极端事件被平滑处理，实际海表温度（SST）在年际或季节时间尺度上的变化没有反映在这些记录中。此外，同一核芯的不同代理海温重建结果存在显著偏差。本研究将首次生成北大西洋不同地区（冰岛、缅因湾、北海）海温、盐度和初级生产力的连续的、千年尺度的、定量的、多代理记录（δ18O、δ13C、Sr/Ca， Δ47），提供年际和适当的季节分辨率。主要的年表将由长寿命的双壳类动物北极岛的壳构成，这些壳的寿命重叠。结果将显著提高我们对海洋极锋和区域/盆地范围的水文格局、远相关、海洋-大气耦合、年代际气候变率和地表水快速扰动的时间动力学的理解。这些新记录可作为海洋-大气耦合气候数值模式的输入变量，以减少未来模拟中的不确定性。

Spatiotemporal high-resolution marine proxy records, specifically from extratropical settings, are es-sential to understand forcing and feedback mechanisms operating within the Earth system. As yet, however, even the best resolved record, a sediment core from offshore North Iceland, provides only a 2-5 yr resolution and is strongly summer biased. Such data are insufficient to determine how fast regime shifts occurred or to provide details on spatiotemporal climate dynamics. Extreme events are smoothed out, and the actual sea surface temperature (SST) variance on interannual or seasonal time-scales is not reflected in these records. Furthermore, different proxy SST reconstructions from the same core significantly deviate from each other. For the first time, this study will generate unin-terrupted, millennial-scale, quantitative, multiproxy records (δ18O, δ13C, Sr/Ca, Δ47) of SST, salinity and primary productivity from various regions in the North Atlantic (Iceland, Gulf of Maine, North Sea) providing interannual – and where appropriate seasonal – resolution. Master chronologies will be constructed from shells with overlapping life-spans of the long-lived bivalve, Arctica islandica. Results will significantly improve our understanding of the temporal dynamics of the oceanic Polar Front and regional / basin-wide hydrographic patterns, teleconnections, ocean-atmosphere couplings, decadal climate variability and rapid perturbations in surface waters. These new records can be used as input variables for numerical models of the coupled ocean-atmosphere climate to reduce the uncertainty in future simulations.