Modelling the surface energetics of patchy Arctic tundra snowcover
Modelling the surface energetics of patchy Arctic tundra snowcover
复制标题
对北极片状苔原积雪的表面能量进行建模
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
A. Wiltshire
中科院分区：
文献类型：
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作者：
A. Wiltshire
结合实地观察和测量，研究了能量平衡的一个不完整的北极苔原积雪在2003/2004年冬季在山区苔原网站在北方瑞典。为了量化片状积雪对地表能量的影响，Met。采用Office Surface Exchange Scheme（MOSES 2）对地面积雪动力学进行了模拟。地面积雪斑块控制的相互作用，吹雪与地面地形和植被，深漂移形成的地形空洞和高大的灌木床。一些裸露的山脊顶部在冬季的大部分时间里都保持着裸露的状态。表面斑块被发现显着改变的表面能量，雪和无雪表面之间的相互作用是准确地数值模拟积雪消融的关键。在大尺度大气模式中，均匀积雪的假设可能会导致模式模拟中的重大误差。研究发现，对于大尺度模型，可以通过分别对有雪和无雪表面使用单独的能量平衡来充分代表非均匀积雪，并具有单一的下伏土壤层。每个表面的比例可以用积雪覆盖率来表示，这是积雪深度分布的参数化。模拟的地表通量，特别是地表径流和热量和水蒸气，被认为是高度敏感的确切形式，这种参数化。没有发现有雪和无雪表面之间湍流能量平流的现场证据
A combination of field observations and measurements were used to study the energy-balance of a patchy arctic tundra snow-cover during the winter of 2003/2004 at a mountain tundra site in Northern Sweden. To quantify the effect of patchy snow-cover on surface energetic, the Met. Office Surface Exchange Scheme (MOSES 2) was employed to simulate surface snow dynamics. Surface snow patchiness was controlled by the interaction of blowing snow with surface topography and vegetation, with deep drifts forming in topographic hollows and tall shrub beds. Some exposed ridge tops remained exposed for the majority of the winter. The surface patchiness was found to significantly alter the surface energetics, and the interaction between snow and snow-free surfaces was critical to accurately numerically simulating snow-cover ablation. The assumption of uniform snow- covers in large-scale atmospheric models may lead to significant errors in model simulations. It was found that for large-scale models, heterogeneous snow-covers can be adequately represented by the use of separate energy-balances for snow and snow-free surfaces respectively with a single underlying soil layer. The proportions of each surface can be represented using a snow covered fraction which is a parameterisation of the distribution of snow depths. Simulated surface fluxes, particularly surface runoff and heat and water vapour, were found to be highly sensitive to the exact form of this parameterisation. No field evidence was found for the advection of turbulent energy between snow and snow-free surfaces