Tracing Glacial Meltwater From the Greenland Ice Sheet to the Ocean Using Gliders
Tracing Glacial Meltwater From the Greenland Ice Sheet to the Ocean Using Gliders
复制标题
使用滑翔机追踪从格陵兰冰盖到海洋的冰川融水
作者：
Hendry K
格陵兰冰盖（GrIS）正在经历重大的质量损失和冰川前沿的淡水排放。来自格陵兰的淡水输入将影响邻近沿海的物理特性，包括重要的深水形成区，并导致全球海平面上升。然而，从GrIS淡水排放增加的生物地球化学的影响是不太好的约束。在这里，我们演示了使用海洋滑翔机上的生物光学传感器来跟踪格陵兰西南部融水的地球化学性质。我们的研究结果表明，新鲜的，沿海沃茨，与冰川融水的氧同位素组成特征，区分由高的光学后向散射和高水平的荧光溶解有机物（FDOM），代表的整体有色溶解有机物池。地转速度的重建被用来表明，这些粒子和FDOM-丰富的沿海沃茨穿过强边界流进入拉布拉多海。进入拉布拉多海的融水输入可能是由中尺度过程驱动的，例如涡流形成和局部测深转向，以及风驱动的Ekman运输。装有生物光学传感器的海洋滑翔机可以提供对溶解和颗粒状冰川衍生物质的高分辨率观测，这些物质是了解融水扩散机制及其对未来气候变化的敏感性所必需的。
The Greenland Ice Sheet (GrIS) is experiencing significant mass loss and freshwater discharge at glacier fronts. The freshwater input from Greenland will impact the physical properties of adjacent coastal seas, including important regions of deep water formation and contribute to global sea level rise. However, the biogeochemical impact of increasing freshwater discharge from the GrIS is less well constrained. Here, we demonstrate the use of bio‐optical sensors on ocean gliders to track biogeochemical properties of meltwaters off southwest Greenland. Our results reveal that fresh, coastal waters, with an oxygen isotopic composition characteristic of glacial meltwater, are distinguished by a high optical backscatter and high levels of fluorescing dissolved organic matter (FDOM), representative of the overall colored dissolved organic matter pool. Reconstructions of geostrophic velocities are used to show that these particle and FDOM‐enriched coastal waters cross the strong boundary currents into the Labrador Sea. Meltwater input into the Labrador Sea is likely driven by mesoscale processes, such as eddy formation and local bathymetric steering, in addition to wind‐driven Ekman transport. Ocean gliders housing bio‐optical sensors can provide the high‐resolution observations of both dissolved and particulate glacially derived material that are needed to understand meltwater dispersal mechanisms and their sensitivity to future climatic change.