The treatment of meltwater retention in mass-balance parameterizations of the Greenland ice sheet
The treatment of meltwater retention in mass-balance parameterizations of the Greenland ice sheet
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DOI：
10.3189/172756400781819941
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发表时间：
2000-01-01
期刊：
影响因子：
--
通讯作者：
Huybrechts, P
中科院分区：
文献类型：
--
作者：
Janssens, I;Huybrechts, P
在研究格陵兰冰盖的表面质量平衡时，不能忽视积雪中的渗透和/或再冻结对融水径流的保留。在本文中，我们做了详细的比较，在文献中提出的几种治疗占这个过程中的大规模质量平衡参数化。格陵兰冰盖的融化计算与修订的度日模型，使用更新的数据集的表面海拔和降水率在5公里的网格。通过比较质量平衡特性与区域基础上的现有观测结果，重新校准了关键模型参数。我们讨论了融水保留的格陵兰冰盖的整体质量平衡和气候变化的敏感性，并显示各种方法的有效保留分数模式的光的作用。作为一个主要的结论，它似乎是整体的结果是非常相似的各种模型，但融水保留有一个大的空间变化，而不是简单的治疗。使用最全面的保留模型，径流的敏感性被认为是+0.35毫米degreesC（-1）的海平面变化每年。我们还提出了一个新的地图，不同的区域（相）的特点，积累面积的格陵兰冰盖，这是有用的解释现场数据和校准卫星观测。
Retention of meltwater runoff by percolation and/or refreezing in the snowpack cannot be neglected when studying the surface mass balance of the Greenland ice sheet. In this paper, we make a detailed comparison of several treatments proposed in the literature to account for this process in large-scale mass-balance parameterizations. The melt on the Greenland ice sheet is calculated with a revised degree-day model using updated datasets of surface elevation and precipitation rate on a 5 km grid. Crucial model parameters are recalibrated by comparing mass-balance characteristics with available observations on a regional basis. We discuss the role of meltwater retention in the light of the overall mass balance of the Greenland ice sheet and its sensitivity to climatic change, and display patterns of effective-retention fractions for the various methods. As a main conclusion, it appears that overall results are quite similar for the various models, but that meltwater retention has a large spatial variation not described by the simple treatments. Using the most comprehensive retention model, the sensitivity of the runoff is found to be +0.35 mm degreesC(-1) of sea-level change per year. We also present a new map of the different zones (facies) that characterize the accumulation area of the Greenland ice sheet, which is useful for interpreting field data and calibrating satellite observations.