Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.

中文翻译：

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改进的表面能量平衡模型在育空地区圣埃利亚斯山脉的两个大型山谷冰川中的应用

冰川表面融化速率通常使用表面能量平衡 (SEB) 模型进行建模，其输出应用于将基于点的质量平衡测量扩展到区域尺度、评估水资源可用性、检查冰上水文以及研究表面融化和冰之间的关系动力学。我们提出了一种改进的 SEB 模型，该模型通过以下方式解决了现有模型的主要局限性：（1）从 Landsat 8 图像中获取高分辨率（30 m）表面反照率，（2）通过高浮雕地形计算投射到冰川表面的阴影，以模拟入射短波辐射，(3) 开发一种算法来绘制足够厚的碎片以隔离冰川表面，以及 (4) 提出与地下热传导模型耦合的 SEB 模型的公式。我们使用来自加拿大育空地区圣埃利亚斯山脉的 Kaskawulsh 冰川和 Nàłùdäy (Lowell) 冰川的 6 年原位气象数据来驱动该模型，并根据原位测量结果验证输出。模拟的季节性融化与多年来在两个冰川的一系列海拔高度内的观测结果一致，并具有高质量的现场观测。当有足够的输入数据可用时，我们建议应用该模型来研究表面融化对单个冰川的影响。