On the importance of the albedo parameterization for the mass balance of the Greenland ice sheet in EC-Earth
On the importance of the albedo parameterization for the mass balance of the Greenland ice sheet in EC-Earth
复制标题
论反照率参数化对于 EC-地球格陵兰冰盖质量平衡的重要性
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Qiong Zhang
中科院分区：
文献类型：
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作者：
M. Helsen;R. Wal;T. Reerink;R. Bintanja;M. S. Madsen;Shuting Yang;Qiang Li;Qiong Zhang
抽象。由于新雪的沉积、干雪的老化、裸冰暴露、融化和径流的影响，冰盖表面的覆盖度随时间而变化。目前，在地球系统模型EC-Earth中，冰盖覆盖率的计算是高度参数化的，对常年积雪厚的地区采用恒定值。这是格陵兰冰盖（GrIS）的表面质量平衡（SMB）在模式中解决不好的一个重要原因。本研究的目的是提高SMB强迫的GrIS通过评估不同的参数设置在一个snow mountando计划。通过允许冰盖融化度作为干湿条件的函数而变化，融化度和融化速率的空间分布得到改善。然而，SMB的空间分布在EC-Earth没有显着改善。作为一个原因，我们发现在目前的雪冰计划遗漏，如雪和冰的单独处理和重新冻结的影响。由此产生的SMB从较低分辨率的全球气候模式地形降尺度到较高分辨率的冰盖地形的GrIS，这样，这些不同的SMB气候的长期演变的GrIS的影响进行测试冰盖模型模拟。从这些冰盖的模拟，我们得出结论，一个衰减的冰的响应时间短，在潮湿的条件下，一个冰的计划执行最好的长期模拟冰盖体积。这将导致在一个优化的ECONDO参数化，可用于未来的EC-Earth模拟与交互式冰盖组件。
Abstract. The albedo of the surface of ice sheets changes as a function of time due to the effects of deposition of new snow, ageing of dry snow, bare ice exposure, melting and run-off. Currently, the calculation of the albedo of ice sheets is highly parameterized within the earth system model EC-Earth by taking a constant value for areas with thick perennial snow cover. This is an important reason why the surface mass balance (SMB) of the Greenland ice sheet (GrIS) is poorly resolved in the model. The purpose of this study is to improve the SMB forcing of the GrIS by evaluating different parameter settings within a snow albedo scheme. By allowing ice-sheet albedo to vary as a function of wet and dry conditions, the spatial distribution of albedo and melt rate improves. Nevertheless, the spatial distribution of SMB in EC-Earth is not significantly improved. As a reason for this, we identify omissions in the current snow albedo scheme, such as separate treatment of snow and ice and the effect of refreezing. The resulting SMB is downscaled from the lower-resolution global climate model topography to the higher-resolution ice-sheet topography of the GrIS, such that the influence of these different SMB climatologies on the long-term evolution of the GrIS is tested by ice-sheet model simulations. From these ice-sheet simulations we conclude that an albedo scheme with a short response time of decaying albedo during wet conditions performs best with respect to long-term simulated ice-sheet volume. This results in an optimized albedo parameterization that can be used in future EC-Earth simulations with an interactive ice-sheet component.
影响因子：
5.2
作者：
Bamber, J. L.;Griggs, J. A.;Steinhage, D.
通讯作者：
Steinhage, D.