The role of the East Greenland Current in the North Atlantic climate variability during the last 200 years

通过东格陵兰洋流（EGC）的极地淡水输出的变化可以影响热盐环流和亚极环流的强度，因此可以调节北大西洋向北的热输送。为了评估EGC在20世纪变暖中的作用及其与北大西洋气候变率的关系，将在三个重点站点研究其古海洋学历史和空间范围；位于东格陵兰中部大陆架（东格陵兰洋流的核心，站点1），北冰岛大陆架（站点2）和格陵兰东南部大陆架上的丹麦海峡，位于极锋区域。第一次，古海洋学数据集，跨越最近的过去和20世纪，为EGC核心将在一个次十年的时间尺度上产生。这些基于有孔虫组合的详细研究，加上2号点和3号点的烯酮分析，将有助于评估现代变暖是否以及如何表现在EGC的漂流/海冰和淡水通量中。为此，将在2015年夏季挪威RV G.O. sar的一次巡航中获得新的短沉积物岩心。拟议的重建将与来自北大西洋暖流、西格陵兰洋流、弗拉姆海峡、波罗的海和欧洲大陆的海洋和陆地高分辨率研究联系起来，以便调查不同地区自小冰期以来的时间（同相/非同相）。高分辨率重建EGC的作用将增加我们对20世纪北大西洋地区气候变率触发机制的理解。

Variations in polar freshwater export via the East Greenland Current (EGC) can affect thermohaline circulation and the strength of the Subpolar Gyre and, therefore, can modulate the northward heat transport in the North Atlantic Ocean. To assess the role of the EGC in the 20th century warming and its relation to North Atlantic climate variability, its palaeoceanographic history and spatial extent will be studied at three key sites; on the central East Greenland shelf (core of the East Greenland Current, site1), the North Iceland shelf (site 2) and the Denmark Strait on the SE Greenland shelf, in the area of the Polar Front. For the first time, palaeoceanographic data sets, spanning the most recent past and the 20th century, for the EGC core will be produced at a sub-decadal time scale. These detailed studies based on foraminiferal assemblages, supplemented with alkenone analyses at site 2 and 3, will allow to asses if and how modern warming is manifested in drift/sea ice and freshwater flux of the EGC. For this aim, new short sediment cores will be obtained during a cruise of the Norwegian RV G.O. Sars in summer 2015. The proposed reconstructions will be linked to marine and terrestrial high-resolution studies from the North Atlantic Drift, the West Greenland Current, the Fram Strait, the Baltic Sea and continental Europe, in order to investigate the timing (in-phase/out-of-phase) since the Little Ice Age in the different regions. Reconstructing the role of the EGC at high resolution will increase our understanding of trigger mechanisms underlying climate variability in the North Atlantic region during the 20th century.