Projected climate warming and wettening will have a major impact on the state of glaciers and seasonal snow in High Arctic regions. Following up on a historical simulation (1957–2018) for Svalbard, we make future projections of glacier climatic mass balance (CMB), snow conditions on glaciers and land, and runoff, under Representative Concentration Pathways (RCP) 4.5 and 8.5 emission scenarios for 2019–60. We find that the average CMB for Svalbard glaciers, which was weakly positive during 1957–2018, becomes negative at an accelerating rate during 2019–60 for both RCP scenarios. Modelled mass loss is most pronounced in southern Svalbard, where the equilibrium line altitude is predicted to rise well above the hypsometry peak, leading to the first occurrences of zero accumulation-area ratio already by the 2030s. In parallel with firn line retreat, the total pore volume in snow and firn drops by as much as 70–80% in 2060, compared to 2018. Total refreezing remains largely unchanged, despite a marked change in the seasonal pattern towards increased refreezing in winter. Finally, we find pronounced shortening of the snow season, while combined runoff from glaciers and land more than doubles from 1957–2018 to 2019–60, for both scenarios.

中文翻译：

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从多模型集合加速斯瓦尔巴冰川未来的质量损失

预计的气候变暖和湿润将对北极高地地区的冰川和季节性降雪状况产生重大影响。继斯瓦尔巴群岛的历史模拟（1957-2018 年）之后，我们在代表性浓度路径 (RCP) 4.5 和 8.5 排放情景下对冰川气候质量平衡 (CMB)、冰川和土地上的积雪条件以及径流进行了未来预测2019-60。我们发现，在两种 RCP 情景下，斯瓦尔巴冰川的平均 CMB 在 1957-2018 年期间呈弱正值，在 2019-60 年期间以加速的速度变为负值。模拟的质量损失在斯瓦尔巴群岛南部最为明显，预计平衡线高度将远高于测压峰，导致到 2030 年代首次出现零累积面积比。在冷线撤退的同时，与 2018 年相比，2060 年雪和冷杉的总孔隙体积减少了 70-80%。尽管季节性模式发生了显着变化，冬季再冻结增加，但总再冻结基本保持不变。最后，我们发现雪季明显缩短，而从 1957-2018 年到 2019-60 年，冰川和陆地的总径流在这两种情况下都增加了一倍以上。