Modelling flow and accreted ice in subglacial Lake Concordia, Antarctica
Modelling flow and accreted ice in subglacial Lake Concordia, Antarctica
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模拟南极洲康科迪亚冰下湖的水流和积冰
DOI：
10.1016/j.epsl.2009.06.037
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发表时间：
2009
影响因子：
5.3
通讯作者：
Grosfeld
中科院分区：
文献类型：
--
作者：
Filina;Grosfeld
到目前为止，在南极洲已经发现了150多个冰下湖泊。由于勘探方面的明显挑战，数值建模仍然是获取这些难以获取的物体信息的主要工具之一。到目前为止，只有巨大的沃斯托克湖被详细研究过。本文重点介绍康科迪亚湖-在南极洲的第二大冰下湖泊，大量的地球物理数据已收集。这个湖被大约4000米的冰覆盖，位于圆顶C附近。为了将数值模型应用于难以进入的南极冰下湖泊，需要适当的几何形状和边界条件。在这项研究中，我们提出的航空重力反演的结果，这表明该湖有617平方公里，31立方公里的体积，和最大的水柱厚度为126米。该水深被用作已建立的三维数值湖流模型的几何输入，以模拟环流和基础质量平衡。相比我们的模型研究冰下湖沃斯托克，我们得到一个一般的环流模式，是显着较弱（由于湖的尺寸较小）和反向（由于反向冰面倾斜）。模拟的平均水平和垂直速度分别为0.2 mm/s和0.5 μm/s。大分子对流速度估计值（1.35±0.13 mm/s和0.81±0.08 mm/s）与东方湖的相似。模拟的平均融化速率和冻结速率分别为4.3±1.1 mm/a和1.1±0.3 mm/a，相应的淡水增量为58±27 dm 3/s。沿沿着规定的冰流线积分模型的冻结和融化，使我们能够计算在冰盖底部的积冰的分布和厚度。我们估计，湖泊东北角的体积为2.6±2.0 km 3（占湖泊总体积的8.3±8.2%），面积为159±48 km 2（占湖泊总面积的26±9%）。大约16，800 ± 7，600年，湖水的停留时间明显短于东方湖。
More than 150 subglacial lakes have been discovered in Antarctica so far. Due to obvious challenges with exploration, numerical modelling remains one of the major tools to acquire information about those hard-to-access objects. Until now only the huge Lake Vostok has been investigated in detail. This paper focuses on Lake Concordia — the second largest subglacial lake in Antarctica over which substantial geophysical data has been collected. This lake is covered by about 4000 m ice and is located near Dome C. In order to apply numerical models to the hard-to-access Antarctic subglacial lakes, decent geometries and boundary conditions are required. In this study we present the results of airborne gravity inversion, suggesting that this lake has an area of 617 km2, a volume of 31 km3, and a maximum water column thickness of 126 m. This bathymetry is used as geometry input for an established 3D-numerical lake-flow model to simulate the circulation and basal mass balance. Compared to our model studies of subglacial Lake Vostok, we obtain a general circulation pattern that is significantly weaker (due to the smaller size of the lake) and of reversed orientation (due to the reversed ice surface tilt). The modelled mean horizontal and vertical velocities are in the order of 0.2 mm/s and 0.5 μm/s, respectively. The larger molecular convective velocity estimations (1.35±0.13 mm/s and 0.81±0.08 mm/s) are similar to Lake Vostok's. The modelled average melting and freezing rates are 4.3±1.1 mm/a and 1.1±0.3 mm/a, respectively, and the corresponding fresh water gain is 58±27 dm3/s. Integration of the modelled freezing and melting along prescribed ice flow lines allows us to calculate the distribution and thickness of accreted ice at the ice sheet bottom. We estimate a volume of 2.6±2.0 km3(8.3±8.2% of the total lake volume) occupying the north-eastern corner of the lake covering an area of 159±48 km2(26±9% of the total lake area). With about 16,800±7600 yr, the residence time of the lake's water is significantly shorter than Lake Vostok's.
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南极洲东部冰下湖泊上空获得的机载重力数据反演
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
I. Filina;D. Blankenship;L. Roy;Mrinal K. Sen;T. Richter;J. Holt
通讯作者：
J. Holt
三维数值模型在南极冰下湖沃斯托克湖中的应用
影响因子：
5.2
作者：
Michael J. M. Williams
通讯作者：
Michael J. M. Williams
模拟南极洲冰下沃斯托克湖的混合和循环
影响因子：
2.3
作者：
Grosfeld
通讯作者：
Grosfeld
影响因子：
5.3
作者：
I. Filina;D. Blankenship;M. Thoma;V. Lukin;V. N. Masolov;Mrinal K. Sen
通讯作者：
I. Filina;D. Blankenship;M. Thoma;V. Lukin;V. N. Masolov;Mrinal K. Sen
沃斯托克湖难以到达的水体混合和循环的先验估计
影响因子：
3.2
作者：
A. Wüest;E. Carmack
通讯作者：
E. Carmack