Resolving Small‐Scale Forest Snow Patterns Using an Energy Balance Snow Model With a One‐Layer Canopy
Resolving Small‐Scale Forest Snow Patterns Using an Energy Balance Snow Model With a One‐Layer Canopy
复制标题
使用具有单层冠层的能量平衡雪模型解决小规模森林雪模式
作者：
G. Mazzotti;R. Essery;C. Moeser;T. Jonas
模拟森林中积雪的时空动态具有挑战性，因为所涉及的过程强烈依赖于小尺度冠层的特性。在这项研究中，我们探索了如何将局部冠层结构信息整合到中等复杂度的能量平衡雪模型中，以非常高的空间分辨率复制观测到的雪模式。利用柔性雪模式（FSM2）模拟的雪深分布与在瑞士东部不连续亚高山林分中获得的大量实验数据进行了三个冬季的检验。虽然FSM2中默认的冠层实现无法捕获观测到的雪深变化，但当额外考虑局部冠层覆盖分数和半球面天空视图分数时（均方根误差减少30%），性能得到了显着改善。然而，整个季节真实的雪深分布模式只有在识别近、远冠层元素的有效温度和包含模拟冠层间隙中积雪优先沉积的机制的情况下才能实现。我们证明，通过多样化的冠层结构输入，以反映与不同过程相关的冠层的各个部分，即使是基于广泛使用的过程参数化和冠层指标的简单模型，也可以只进行一些修改就应用于冠层下积雪的高分辨率模拟。所提出的方法可以在常用的陆地表面模型中实施，允许升级实验和开发亚网格参数化，而不需要复杂的高分辨率模型。
Modeling spatiotemporal dynamics of snow in forests is challenging, as involved processes are strongly dependent on small‐scale canopy properties. In this study, we explore how local canopy structure information can be integrated in a medium‐complexity energy balance snow model to replicate observed snow patterns at very high spatial resolutions. Snow depth distributions simulated with the Flexible Snow Model (FSM2) were tested against extensive experimental data acquired in discontinuous subalpine forest stands in Eastern Switzerland over three winters. While the default canopy implementation in FSM2 fails to capture the observed snow depth variability, performance is considerably improved when local canopy cover fraction and hemispherical sky view fraction are additionally accounted for (30% reduction in root mean square error). However, realistic snow depth distribution patterns throughout the season are only achieved if effective temperatures of near and distant canopy elements are discerned and if a mechanism to mimic preferential deposition of snow in canopy gaps is included. We demonstrate that by diversifying the canopy structure input in order to reflect respective portions of the canopy relevant to different processes, even a simple model based on widely used process parameterizations and canopy metrics can be applied for high‐resolution simulations of the sub‐canopy snow cover with just a few modifications. The presented approaches could be implemented in commonly used land surface models, allowing upscaling experiments and development of sub‐grid parameterizations without necessitating complex high‐resolution models.
影响因子：
4.7
作者：
Essery, Richard;Morin, Samuel;Menard, Cecile B.
通讯作者：
Menard, Cecile B.
影响因子：
5.4
作者：
Currier, William Ryan;Lundquist, Jessica D.
通讯作者：
Lundquist, Jessica D.