Alaska's largest city, Anchorage, depends on Eklutna Glacier meltwater for drinking water and hydropower generation; however, the 29 km2 glacier is rapidly retreating. We used a temperature-index model forced with local weather station data to reconstruct the glacier's mass balance for the period 1985–2019 and quantify the impacts of glacier change on discharge. Model calibration involved a novel combination of in situ, geodetic mass-balance measurements and observed snowlines from satellite imagery. A resulting ensemble of 250 best-fitting model parameters was used to model mass balance and discharge. Eklutna Glacier experienced a significant negative trend (−0.31 m w.e. decade−1) in annual mean surface mass balance (mean: −0.62 ± 0.06 m w.e.). The day of the year when 95% of annual melt occurs was five days later in 2011–19 than in 1985–93, demonstrating a prolongation of melt season (May–September). Modeled mean specific discharge increased at 0.14 m decade−1, indicating peak water, the year when annual discharge reaches a maximum due to glacier retreat, has not been reached. Four of the five highest discharge years occurred since 2000. Increases in discharge quantity and melt season length require water resource managers consider future decreased discharge as the glacier continues to shrink.

中文翻译：

---

模拟气候变化对阿拉斯加埃克卢特纳冰川质量平衡和排放的影响，1985-2019 年

阿拉斯加最大的城市安克雷奇依靠 Eklutna Glacier 融水提供饮用水和水力发电；然而，29 公里2冰川正在迅速退缩。我们使用当地气象站数据强制使用的温度指数模型来重建 1985-2019 年期间冰川的质量平衡，并量化冰川变化对流量的影响。模型校准涉及原位、大地质量平衡测量和从卫星图像中观察到的雪线的新组合。由此产生的 250 个最佳拟合模型参数的集合用于模拟质量平衡和排放。Eklutna Glacier 经历了显着的负面趋势（-0.31 m 我们十年-1) 年平均地表质量平衡（平均：-0.62 ± 0.06 m we）。2011-19 年一年中 95% 的融化发生的那一天比 1985-93 年晚了 5 天，表明融化季节（5 月至 9 月）延长了。模拟的平均比流量增加了 0.14 米十年-1，表示峰水，即由于冰川退缩而达到年流量最大的年份，尚未达到。自 2000 年以来排放量最高的五个年份中有四个发生。排放量和融化季节长度的增加要求水资源管理人员考虑未来随着冰川继续缩小而减少的排放量。