The seasonal evolution of the ground thermal regime in cold regions influences hydrologic flow paths, soil biogeochemistry, and hillslope geomorphology. In mountain environments, steep topography produces strong gradients in solar insolation, vegetation, and snowpack dynamics that lead to large differences in soil temperature over short distances, suggesting a need for high-resolution, process-based models that quantify the influence of topography. We present soil temperature and snow depth results from a coupled thermo-hydrologic model compared to field observations from Gordon Gulch, a seasonally snow-covered montane catchment in the Colorado Front Range in the Boulder Creek Critical Zone Observatory. The field site features two instrumented hillslopes with opposing aspects: Despite the persistent snowpack on the north-facing slope, seasonally frozen ground is more prevalent there than the south-facing slope, which experiences significantly higher incoming radiation that prevents the persistence of frozen ground. A novel modeling framework is developed by coupling a surface energy balance model incorporating solar radiation and snowpack processes to an existing subsurface model (PFLOTRAN-ICE). The coupled model is used to reproduce strong aspect-controlled differences in soil temperature and snow depth evident from observations during water years 2013–2016, including a higher incidence of frozen ground under the north-facing slope. Representation of the snowpack and its insulating effects significantly improves soil temperature estimates on the north-facing slope, particularly the duration of soil freezing in the spring, which is underestimated by 1–2 months without including the snowpack.

中文翻译：

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模拟山地山坡上地热系统的方面控制演化

寒冷地区地热状况的季节性演变影响水文流动路径、土壤生物地球化学和山坡地貌。在山地环境中，陡峭的地形在日照、植被和积雪动态方面产生强烈的梯度，导致短距离内土壤温度的巨大差异，这表明需要高分辨率、基于过程的模型来量化地形的影响。我们将热水文耦合模型的土壤温度和雪深结果与戈登峡谷的现场观测结果进行比较，戈登峡谷是博尔德溪临界区天文台科罗拉多前沿山脉季节性积雪覆盖的山地集水区。野外场地有两个相对立面的仪表山坡：尽管朝北的斜坡上持续积雪，那里的季节性冻土比朝南的斜坡更为普遍，朝南的斜坡受到明显更高的入射辐射，从而阻止了冻土的持续存在。通过将结合太阳辐射和积雪过程的表面能量平衡模型耦合到现有的地下模型 (PFLOTRAN-ICE)，开发了一种新型建模框架。耦合模型用于再现 2013-2016 年水年观测中明显的土壤温度和雪深的强烈方面控制差异，包括朝北斜坡下冻土的发生率较高。积雪的表现及其隔热效果显着提高了北坡土壤温度的估计，特别是春季土壤冻结的持续时间，