Lake Ice Break-Up across Peripheral Greenland (2017-2021) from Sentinel-1 SAR

Dataset from Posch, C., Abermann, J., and Silva, T.: Lake ice break-up in Greenland: timing and spatiotemporal variability, The Cryosphere, 18, 2035–2059, https://doi.org/10.5194/tc-18-2035-2024, 2024. Timing of lake ice break-up for 563 lakes across peripheral South, Southwest and Northwest Greenland (< 71° N) from Sentinel-1 synthetic aperture radar (SAR) data for 2017-2021. This is based on an automated detection from dynamic numerical thresholding which utilizes SAR backscatter differences between lake ice surface and open water. The data proves to be conservative and exhibits a mean error of maximum 5 days (i.e., being 5 days later) in break-up timing which is based on a validation against lake ice observations. Based on a observed variability of lake ice break-up timing in the studied period (+/- 8 days), we also produced estimates for a hypothetical 8-days-earlier break-up of all lakes and its manifestation in execess energy at the lake, which was calculated from site-specific RACMO2.3p incoming shortwave radiation data. More information is to be found in the README file.本数据集源自Posch C、Abermann J与Silva T发表于《冰冻圈》（*The Cryosphere*）2024年第18卷第2035–2059页的研究成果《格陵兰湖冰解冻时间及时空变异性》，DOI: 10.5194/tc-18-2035-2024。本数据集涵盖2017至2021年间格陵兰南部、西南部及西北部外围区域（北纬71°以南）共563个湖泊的湖冰解冻时间，数据基于哨兵1号（Sentinel-1）合成孔径雷达（synthetic aperture radar, SAR）观测数据获取。该数据集采用动态数值阈值法实现自动化检测，通过对比湖冰表面与开阔水体的SAR后向散射差异完成识别。经湖冰原位观测数据验证，本数据集结果偏保守，解冻时间的平均最大误差为5天（即检测结果较实际解冻时间晚5天）。基于研究时段内湖冰解冻时间的观测变异性（±8天），本研究还开展了两类估算：一是所有湖泊假设提前8天解冻的情景模拟，二是基于各站点专属RACMO2.3p入射短波辐射数据计算的该情景下湖泊过剩能量变化。更多详细信息请参阅README文件。