Water temperature, salinity, and others collected from autonomous underwater vehicle in Sarqardleq Fjord, West Greenland from 2012-07-18 to 2012-07-24

Measurements of near-ice ( less than 200 meters (m)) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we provide detailed hydrographic and bathymetric measurements collected with an autonomous underwater vehicle as close as 150m from the ice–ocean interface of the Saqqarliup sermia–Sarqardleq Fjord system, West Greenland. Analysis in combination with modeled and observed subglacial discharge locations and magnitudes, showed evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations (Stevens et al., 2016, doi:10.5194/tc-10-417-2016). The near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass, qualitatively consistent with results from an idealized plume model.

近冰区（距冰体小于200米）的水文与近冰川末端冰下水文测量数据长期缺失，这在很大程度上源于崩解冰川边缘作业的极高难度。本研究提供了依托自主水下航行器（Autonomous Underwater Vehicle, AUV）获取的高精度水文与水深测量数据，采集位置距西格陵兰萨卡柳普冰川-萨卡德莱克峡湾系统的冰-洋界面仅约150米。结合模拟与观测得到的冰下径流位置及径流量开展分析后，研究发现了两种性质与分布特征均存在显著差异的主要冰川改性水（Glacially Modified Water, GMW）类型（Stevens et al., 2016, doi:10.5194/tc-10-417-2016）。近冰区观测结果与冰下径流路径表明，该冰川的径流主要产生于两处离散位置，并由此形成两种截然不同的冰川改性水团。此外，冰下径流量最大的位置对应密度更低、盐度更淡的冰川改性水团，这一定性结果与理想羽流模型的模拟结果相符。