Impact of ice-shelf basal melting on inland ice-sheet thickness: a model study
Impact of ice-shelf basal melting on inland ice-sheet thickness: a model study
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冰架基底融化对内陆冰盖厚度的影响：模型研究
DOI：
10.3189/2012aog60a170
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发表时间：
2012
影响因子：
2.9
通讯作者：
Sylvia Massmann
中科院分区：
文献类型：
--
作者：
J. Determann;M. Thoma;K. Grosfeld;Sylvia Massmann
摘要从冰盖流向海洋的冰流包含了导致未来海平面上升的最大潜力。在南极洲，大多数物质流动是通过覆盖南极一半以上海岸线的延伸冰架区域发生的。扩展最广的冰架是费尔奇纳-罗恩冰架和罗斯冰架，这两个冰架占基面融化造成的总质量损失的30%左右。这里的基本融化速率显示出-lt；0.5 mA-1的小到中等的平均幅度。相比之下，阿蒙森海和别林豪森海较小但最脆弱的冰架显示出更高的融化速率(高达30 mA-1)，但由于冰架的小尺寸，总体上基本质量损失相对较小。然而，对于这两个特征冰架区域来说，关键问题是海洋融化以及冰架厚度的变化对腹地冰块流动动力学的影响。从理论上讲，冰架背压起到了稳定冰盖的作用，从而稳定了海平面以上的冰量。我们使用三维(3-D)热力学冰流模式RIMBAY来研究规则形状的模型区域内的冰流，包括冰盖、冰架和开阔的海洋区域。通过使用熔化情景进行微扰研究，我们发现了一种类似滞后的行为。实验表明，当扰动被关闭时，系统恢复到初始状态。在随时间变化的模型研究中，高达2 ma-1的平均基本熔融速率和由我们的三维海洋模型ROMBAX计算的空间可变的熔融作为基本边界条件。经过1000年的模拟，监测到了冰量和接地线位置的变化，揭示了高达40GTa-1的质量损失。
Abstract Ice flow from the ice sheets to the ocean contains the maximum potential contributing to future eustatic sea-level rise. In Antarctica most mass fluxes occur via the extended ice-shelf regions covering more than half the Antarctic coastline. The most extended ice shelves are the Filchner–Ronne and Ross Ice Shelves, which contribute ~30% to the total mass loss caused by basal melting. Basal melt rates here show small to moderate average amplitudes of <0.5ma–1. By comparison, the smaller but most vulnerable ice shelves in the Amundsen and Bellinghausen Seas show much higher melt rates (up to 30 ma–1), but overall basal mass loss is comparably small due to the small size of the ice shelves. The pivotal question for both characteristic ice-shelf regions, however, is the impact of ocean melting, and, coevally, change in ice-shelf thickness, on the flow dynamics of the hinterland ice masses. In theory, ice-shelf back-pressure acts to stabilize the ice sheet, and thus the ice volume stored above sea level. We use the three-dimensional (3-D) thermomechanical ice-flow model RIMBAY to investigate the ice flow in a regularly shaped model domain, including ice-sheet, ice-shelf and open-ocean regions. By using melting scenarios for perturbation studies, we find a hysteresis-like behaviour. The experiments show that the system regains its initial state when perturbations are switched off. Average basal melt rates of up to 2 ma–1 as well as spatially variable melting calculated by our 3-D ocean model ROMBAX act as basal boundary conditions in time-dependent model studies. Changes in ice volume and grounding-line position are monitored after 1000 years of modelling and reveal mass losses of up to 40 Gt a–1.
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
对冰下湖泊模拟中的状态方程和冰点方程的评述
影响因子：
5.3
作者：
Grosfeld
通讯作者：
Grosfeld