Sergienko Olga
Princeton University, Atmospheric and Oceanic Sciences Program, Princeton, New Jersey 08540, USA.
Phys Rev E. 2025 Jun;111(6):L062201. doi: 10.1103/n3xh-bt95.
This article is part of a Physical Review Collection on the Physics of Changing Climate. Antarctic ice shelves, floating extensions of the Antarctic Ice Sheet, regulate the ice discharge from the ice-sheet interior into the surrounding oceans and, as a result, the ice-sheet contribution to the sea level. On a timescale longer than several months, the flow of bodies of ice, such as ice sheets and ice shelves, is controlled by the ice non-Newtonian viscosity and its rheological parameters, i.e., the ice stiffness and the exponent of the rheology power-law functional form. Recent studies suggest that the value of the rheological exponent may be higher than that typically used in studies of ice shelves. It is unclear, however, what effects this difference might have on the behavior of ice shelves in general and particularly on multidecadal timescales. In order to evaluate such effects on the behavior of the Pine Island Glacier Ice Shelf, one of the fastest changing regions in Antarctica, a suite of numerical simulations has been performed. In these simulations, the ice-shelf rheological parameters have been constrained by means of inverse methods using remote-sensing observations. The results show that for the same submarine melting and different rheological parameters, the difference between the ice-shelf states (thickness and speed) is of the order of 5%. In contrast, for the same rheological parameters and different submarine melting, the difference between the ice-shelf states is significantly larger, of the order of 15% for ice speed and 40% for ice thickness. These results suggest that ice shelves have much higher sensitivity to the impacts of climate conditions, such as submarine melting, than to their rheological parameters.
本文是《物理评论集：气候变化物理学》的一部分。南极冰架是南极冰盖的漂浮延伸部分，它调节着冰盖内部向周围海洋的冰排放，进而影响冰盖对海平面的贡献。在数月以上的时间尺度上，冰体（如冰盖和冰架）的流动受冰的非牛顿粘性及其流变参数控制，即冰的刚度和流变幂律函数形式的指数。近期研究表明，流变指数的值可能高于冰架研究中通常使用的值。然而，目前尚不清楚这种差异总体上对冰架行为会有何种影响，尤其是在数十年时间尺度上。为了评估这种差异对南极变化最快的地区之一——松岛冰川冰架行为的影响，我们进行了一系列数值模拟。在这些模拟中，利用遥感观测数据通过反演方法确定了冰架的流变参数。结果表明，对于相同的海底融化情况和不同的流变参数，冰架状态（厚度和速度）之间的差异约为5%。相比之下，对于相同的流变参数和不同的海底融化情况，冰架状态之间的差异要大得多，冰速度差异约为15%，冰厚度差异约为40%。这些结果表明，冰架对诸如海底融化等气候条件影响的敏感性远高于对流变参数的敏感性。
