Modelled sensitivity of the snow regime to topography, shrub fraction and shrub height
Modelled sensitivity of the snow regime to topography, shrub fraction and shrub height
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DOI：
10.5194/hess-18-2375-2014
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发表时间：
2014-01-01
影响因子：
6.3
通讯作者：
Pomeroy, J.
中科院分区：
文献类型：
--
作者：
Menard, C. B.;Essery, R.;Pomeroy, J.
最近的研究表明，灌木正在北极的高纬度和高海拔地区定居。灌木影响风的运输、积雪的积累和融化，但关于灌木扩张如何影响融雪速度和时间的敏感性研究很少。这里介绍了一个三源能量平衡模式(3SOM)，该模式计算大气、雪、无雪地面和植被之间的垂直和水平能量通量，从而允许单元内平流。三源结构被专门用来研究与单源或双源模型无法解决的片状积雪相关的灌木-冻土带过程。评价了该模式对高原冻土带山谷积雪状况的模拟能力，用吹雪输送和升华模式模拟了预融雪的分布，用3SOM模拟了融雪。在点模拟中模拟湍流通量和在分布运行中模拟广泛的空间模式方面取得了一些成功，即使单元之间缺乏平流导致熔体速率被低估。然后，这些模型被用来研究山谷中的降雪状况对不同的灌木覆盖和地形的敏感性。结果表明，对于区域平均灌木覆盖度
Recent studies show that shrubs are colonizing higher latitudes and altitudes in the Arctic. Shrubs affect the wind transport, accumulation and melt of snow, but there have been few sensitivity studies of how shrub expansion might affect snowmelt rates and timing. Here, a three-source energy balance model (3SOM), which calculates vertical and horizontal energy fluxes - thus allowing within-cell advection - between the atmosphere, snow, snow-free ground and vegetation, is introduced. The three-source structure was specifically adopted to investigate shrub-tundra processes associated with patchy snow cover that single-or two-source models fail to address. The ability of the model to simulate the snow regime of an upland tundra valley is evaluated; a blowing snow transport and sublimation model is used to simulate premelt snow distributions and 3SOM is used to simulate melt. Some success at simulating turbulent fluxes in point simulations and broad spatial pattern in distributed runs is shown even if the lack of advection between cells causes melt rates to be underestimated. The models are then used to investigate the sensitivity of the snow regime in the valley to varying shrub cover and topography. Results show that, for domain average shrub fractional cover