Variations in ocean currents, sea ice concentration, and sea surface temperature along the North-East coast of Greenland (NEG-OCEAN)

基于遥感数据，应确定格陵兰东北海岸海面流的时间演变，并与海冰浓度和海面温度一起进行分析，以便为研究(与两个捆绑项目一起)冰盖、海洋和海冰之间的耦合机制提供基础。在过去的几十年中，格陵兰冰盖经历了冰盖质量损失的急剧增加，这既是由于表面融化加剧，也是由于出口冰川加速和更高的冰输出速率。与前几十年相比，格陵兰冰盖对全球海平面上升的贡献在过去20年翻了一番。融化的水改变了冰盖的热结构，影响了基本边界条件。此外，冰川舌头和海水之间的相互作用对冰川的动态有直接影响。温暖的峡湾水域影响了冰川下的融化，增加了冰通量。相反，流入近岸海域的淡水通量的增加会影响沿岸的水和能量输运。因此，研究冰盖、其海洋出口冰川和海洋环流之间的反馈机制依赖于大气强迫是理解这一复杂系统及其在全球范围内的变化的极其重要的一步。本项目侧重于海洋部分。利用专门的卫星高度计数据处理，结合最新的重力场模型，估计了可转换为非地转速度场的动态海洋地形的时间序列。对地形、海冰浓度和海温的主成分分析应找出最主要的模式，以便为研究冰盖质量损失的相关性和研究冰盖、海洋和海冰之间的耦合机制提供依据。

Based on remote sensing data the temporal evolution of ocean surface currents at the North Eastcoast of Greenland shall be determined and - together with sea ice concentration and sea surfacetemperature - analyzed in order to provide a basis for studying (together with two bundled projects)the coupling mechanism between ice sheet, ocean, and sea ice.During the last decades the Greenland ice sheets experienced a strongly increased mass loss of icesheets, both due to enhanced surface melting and due to the acceleration of outlet glaciers andhigher ice export rates. Compared to the earlier decades, the conuibution of the Greenland ice sheetto global sea level rise doubled during the last two decades. Melt water changes the thermalstmcture of the ice sheet and influences the basal boundary conditions. In addition, interactionsbetween the glacier tongues and the ocean water have a direct impact on the dynamics of outletglaciers. Warm fjord waters impact subglacial melting and increase the ice flux. Conversely, theincrease of fresh water flux into the coastal sea su^ongly influences the water and energy ü-ansportalong the coast. The investigation of the feedback mechanisms between the ice sheet, its marinebased outlet glaciers and the ocean circulation in dependence of atmospheric forcing is therefore anextremely important step in understanding the variability of this complex system and itsimplications on a global scale. The present project focuses on the ocean component. A dedicatedprocessing of satellite altimeter data combined with the most recent gravity field models is used toestimate a time series of the dynamic ocean topography which can be transformed into ageostrophic velocity field. Principal component analyses of topography, sea ice concentration andsea surface temperature shall identify the most dominant modes, in order to provide a basis forinvestigating correlation with mass loss of ice sheets and studying the coupling mechanism betweenice sheet, ocean and sea ice.