Ocean Stratification and Low Melt Rates at the Ross Ice Shelf Grounding Zone
Ocean Stratification and Low Melt Rates at the Ross Ice Shelf Grounding Zone
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DOI：
10.1029/2018jc013987
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发表时间：
2018-10-01
影响因子：
3.6
通讯作者：
King, Matt A.
中科院分区：
文献类型：
--
作者：
Begeman, Carolyn Branecky;Tulaczyk, Slawek M.;King, Matt A.
简单语言摘要 海洋驱动的冰架融化是南极洲冰流失的主要机制。然而，由于难以进入冰架下洋腔，人们对冰架融化与海洋条件之间的关系知之甚少，特别是在冰从接地过渡到漂浮的接地区附近。我们展示了罗斯冰架接地区的首次钻孔海洋学观测，罗斯冰架是南极洲面积最大的冰架。与接地区附近的潮流混合水柱的预测相反，我们发现罗斯冰架的水域是垂直分层的。在潮汐周期的两个不同部分的测量期间，洋腔中深度的当前速度没有显着变化。根据相敏雷达观测推断，观察到的分层导致接地区这部分附近的融化速率较低。这些熔化速率一般为
Plain Language Summary Ocean-driven melting of ice shelves is a primary mechanism for ice loss from Antarctica. However, due to the difficulty in accessing the sub-ice shelf ocean cavity, the relationship between ice shelf melting and ocean conditions is poorly understood, particularly near the grounding zone, where the ice transitions from grounded to floating. We present the first borehole oceanographic observations from the grounding zone of the Ross Ice Shelf, Antarctica's largest ice shelf by area. Contrary to predictions that tidal currents near grounding zones mix the water column, we found that Ross Ice Shelf waters were vertically stratified. Current velocities at middepth in the ocean cavity did not change significantly over measurement periods at two different parts of the tidal cycle. The observed stratification resulted in low melt rates near this portion of the grounding zone, inferred from phase-sensitive radar observations. These melt rates were generally