Greenland Marine-Terminating Glacier Retreat Data

The thinning, acceleration, and retreat of Greenland glaciers since the mid-1990s has been attributed to the enhanced intrusion of warm Atlantic Waters (AW) into fjords, but this assertion has not been quantitatively tested on a Greenland-wide basis or included in numerical models. Here, we investigate how AW influenced the retreat of 226 marine-terminating glaciers by combining ocean modeling, remote sensing, and in-situ observations. We identify 74 glaciers standing in deep fjords with warm AW that retreated when ocean warming induced a 48% increase in glacier undercutting that controlled 62% of the glacier mass loss in 1992-2017. Conversely, 27 glaciers calving on protective, shallow ridges and 24 glaciers standing in cold, shallow waters did not retreat; and 10 glaciers retreated when their floating sections collapsed. The mechanisms of ice front evolution remain undiagnosed at 87 glaciers with no ocean and bathymetry data, but these glaciers only account for 16% of the retreat. Projections of glacier evolution that exclude ocean-induced glacier undercutting may underestimate future mass losses by at least a factor two. In this dataset, we present data for 226 glaciers over the time period 1985-2017. In particular, we provide estimates of glacier geometry, ocean thermal forcing on the continental shelf and at the glacier terminus, ice velocity, ocean-induced melt, and thinning-induced retreat. Most of the data is compiled in a netCDF file for each of the 226 glaciers investigated durign the study period, with the exception of ice front boundaries for the years 1985-2019 digitized from Landsat 5, 7, and 8 imagery, which we provide in a single shapefile. In addition, we include a PDF which displays the data enclosed for each glacier.自20世纪90年代中期以来，格陵兰岛冰川的变薄、流速加速与后退，被归因于暖大西洋水（Warm Atlantic Waters, AW）涌入峡湾的强度增强，但这一论断尚未在格陵兰全岛范围内开展定量验证，也未被纳入数值模式之中。本研究结合海洋数值模拟、遥感观测与原位实测数据，探究了AW对226条入海冰川后退过程的影响。我们识别出74条位于深峡湾且受暖大西洋水影响的冰川：在1992-2017年期间，海洋变暖使得冰川底部掏蚀强度提升48%，该过程主导了62%的冰川物质损失，进而驱动这些冰川发生后退。与之相反，27条在保护性浅脊上崩解的冰川，以及24条位于寒冷浅水环境中的冰川，并未出现后退现象；另有10条冰川在其浮动冰体发生坍塌后出现后退。针对87条缺乏海洋与水深地形数据的冰川，其冰前锋演化机制仍未明确，但这类冰川的后退量仅占总后退量的16%。若在冰川演化预测中排除海洋诱导的冰川底部掏蚀过程，未来冰川物质损失的估算值至少会被低估一倍。本数据集包含了1985-2017年间226条冰川的相关数据。具体而言，我们提供了冰川几何形态、大陆架与冰川末端的海洋热强迫、冰流速、海洋诱导的冰川消融以及变薄驱动的后退幅度等估算结果。除了从Landsat 5、7、8影像中数字化得到的1985-2019年冰前锋边界数据（以单个shapefile格式提供）外，其余大部分数据均按研究时段内的226条冰川分别整理为netCDF文件。此外，我们还附带了一份PDF文档，用于展示每条冰川的相关数据。