Since the 1970s, Arctic sea ice has undergone unprecedented change, becoming thinner, less extensive and less resilient to summer melt. Snow’s high albedo greatly reduces solar absorption in sea ice and the upper ocean, which mitigates sea–ice melt and ocean warming. However, the drivers of summertime snow depth variability are unknown. The Arctic Oscillation is a mode of natural climate variability, influencing Arctic snowfall and air temperatures. Thus, it may affect summertime snow conditions on Arctic sea ice. Here we examine the role of the Arctic Oscillation in summer snow depth variability on Arctic sea ice in 1980–2020 using atmospheric reanalysis, snow modelling and satellite data. The positive phase leads to greater snow accumulation, ranging up to ~4.5 cm near the North Pole, and higher surface albedo in summer. There are more intense, frequent Arctic cyclones, cooler temperatures aloft and greater snowfall relative to negative and neutral phases; these conditions facilitate a more persistent summer snow cover, which may lessen sea-ice melt and ocean warming. The Arctic Oscillation influence on summertime snow weakens after 2007, which suggests that future warming and Arctic sea-ice loss might modify the relationship between the Arctic Oscillation and snow on Arctic sea ice.

自 1970 年代以来，北极海冰发生了前所未有的变化，变得更薄、范围更小、对夏季融化的适应能力更差。雪的高反照率大大减少了海冰和上层海洋对太阳的吸收，从而缓解了海冰融化和海洋变暖。然而，夏季雪深变化的驱动因素尚不清楚。北极涛动是自然气候变化的一种模式，影响北极降雪和气温。因此，它可能会影响北极海冰上的夏季积雪状况。在这里，我们使用大气再分析、积雪建模和卫星数据研究了 1980-2020 年北极海冰夏季雪深变化中北极涛动的作用。正阶段导致更大的积雪，在北极附近高达 ~4.5 厘米，夏季地表反照率更高。相对于负和中性阶段，北极气旋更强烈、更频繁，高空温度较低，降雪量更大;这些条件促进了更持久的夏季积雪，这可能会减少海冰融化和海洋变暖。北极涛动对夏季积雪的影响在 2007 年后减弱，这表明未来的变暖和北极海冰的消失可能会改变北极涛动与北极海冰上的积雪之间的关系。