Surface melting occurs across many of Antarctica’s ice shelves, mainly during the austral summer. The onset, duration, area and fate of surface melting varies spatially and temporally, and the resultant surface meltwater is stored as ponded water (lakes) or as slush (saturated firn or snow), with implications for ice-shelf hydrofracture, firn air content reduction, surface energy balance and thermal evolution. This study applies a machine-learning method to the entire Landsat 8 image catalogue to derive monthly records of slush and ponded water area across 57 ice shelves between 2013 and 2021. We find that slush and ponded water occupy roughly equal areas of Antarctica’s ice shelves in January, with inter-regional variations in partitioning. This suggests that studies that neglect slush may substantially underestimate the area of ice shelves covered by surface meltwater. Furthermore, we found that adjusting the surface albedo in a regional climate model to account for the lower albedo of surface meltwater resulted in 2.8 times greater snowmelt across five representative ice shelves. This extra melt is currently unaccounted for in regional climate models, which may lead to underestimates in projections of ice-sheet melting and ice-shelf stability.

南极洲许多冰架都会发生表面融化，主要发生在南半球夏季。地表融化的开始、持续时间、面积和命运在空间和时间上都有所不同，由此产生的地表融水以蓄水（湖泊）或雪泥（饱和冰雪或雪）的形式储存，对冰架水力压裂、冰雪空气含量产生影响还原、表面能量平衡和热演化。这项研究将机器学习方法应用于整个 Landsat 8 图像目录，以获取 2013 年至 2021 年间 57 个冰架的雪泥和积水面积的月度记录。我们发现，雪泥和积水在 2013 年至 2021 年期间占据南极洲冰架的面积大致相等。一月，区域间划分存在差异。这表明忽略雪泥的研究可能大大低估了地表融水覆盖的冰架面积。此外，我们发现，调整区域气候模型中的地表反照率以考虑地表融水的较低反照率，导致五个代表性冰架的融雪量增加了 2.8 倍。这种额外的融化目前在区域气候模型中没有得到考虑，这可能导致对冰盖融化和冰架稳定性的预测被低估。