Surface melt is an important process for the stability of ice shelves, and therewith the Antarctic ice sheet. In Antarctica, absorption of solar radiation is mostly the largest energy source for surface melt, which is further enhanced by the snowmelt‐albedo feedback (SMAF): Refrozen snow has a lower albedo than new snow, which causes it to absorb more solar radiation, further increasing the energy available for surface melt. This feedback has previously been shown to increase surface melt by approximately a factor of 2.5 at Neumayer Station in East Antarctica. In this study, we use a regional climate model to quantify SMAF for the entire Antarctic ice sheet. We find that it is most effective on ice shelves in East Antarctica, and is less important in the Antarctic Peninsula and on the Ross and Filchner‐Ronne ice shelves. We identify a relationship between SMAF and average summer 2 m air temperatures, and find that SMAF is most important around 265 ± 2 K. On a subseasonal scale, we identify several parameters that contribute to SMAF: the length of dry periods, the time between significant snowfall events and snowmelt events, and prevailing temperatures. We then apply the same temperature dependency of SMAF to the Greenland ice sheet and find that it is potentially active in a narrow band around the ice sheet, and finally discuss how the importance of SMAF could change in a warming climate.

中文翻译：

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南极地区融雪-反照率反馈的空间变异性

表面融化是保持冰架以及南极冰盖稳定的重要过程。在南极洲，太阳辐射的吸收主要是表面融化的最大能源，而融雪反照率反馈（SMAF）进一步增强了该能量：冷冻雪的反照率比新雪低，这导致它吸收了更多的太阳辐射，进一步增加了可用于表面熔化的能量。先前已显示，这种反馈在南极东部的Neumayer站将表面融化增加了约2.5倍。在这项研究中，我们使用区域气候模型来量化整个南极冰盖的SMAF。我们发现它在南极东部的冰架上最有效，而在南极半岛以及Ross和Filchner-Ronne的冰架上则没有那么重要。我们确定了SMAF与夏季平均2 m空气温度之间的关系，发现SMAF在265±2 K附近最为重要。在一个亚季节尺度上，我们确定了一些有助于SMAF的参数：干旱时间的长短，重大降雪事件和融雪事件以及当时的温度。然后，我们将SMAF的相同温度依赖性应用于格陵兰冰原，发现它在冰原周围的狭窄带中可能具有活性，最后讨论了SMAF在变暖的气候中如何改变重要性。和普遍的温度。然后，我们将SMAF的相同温度依赖性应用于格陵兰冰原，发现它可能在冰原周围的狭窄区域中活跃，最后讨论了SMAF在变暖的气候中如何改变重要性。和普遍的温度。然后，我们将SMAF的相同温度依赖性应用于格陵兰冰原，发现它在冰原周围的狭窄带中可能具有活性，最后讨论了SMAF在变暖的气候中如何改变重要性。