The ocean boundary layer beneath Larsen C Ice Shelf: insights from large-eddy simulations with a near-wall model
The ocean boundary layer beneath Larsen C Ice Shelf: insights from large-eddy simulations with a near-wall model
复制标题
拉森 C 冰架下方的海洋边界层：使用近壁模型进行大涡流模拟的见解
DOI：
10.1175/jpo-d-21-0166.1
复制
发表时间：
2022
影响因子：
3.5
通讯作者：
A. Jenkins
中科院分区：
文献类型：
--
作者：
C. Vreugdenhil;John R. Taylor;P. Davis;K. Nicholls;P. Holland;A. Jenkins
南极冰架的融化速度对海平面上升和未来气候情景至关重要。最近在拉森C冰架下的观测揭示了一个高度湍流的海洋边界层，并提出了关于这些丰富的流动动力学对海洋热传输和冰架融化速度的影响的问题(Davis和Nicholls 2019)。在现场观测的直接推动下，我们进行了大涡模拟(LES)，以进一步研究拉森C冰架下的海洋边界层。LES以均匀的温度和盐度(T/S)进行初始化，包括一个真实的潮汐周期和一个小的基坡。在上边界采用了基于Vreugdenhil和Taylor(2019)的新的参数化方法来模拟近壁湍流和底部熔化。得到的垂直T/S剖面、熔融速率和摩擦速度与拉森C冰架的观测结果吻合得很好。瞬时融化速率随潮汐周期变化很大，较快的水流增加了热量向冰基的湍流和混合。在冰底下方形成了一个埃克曼层，由于海流的强烈垂直切变，在混合层和层结区(深度≈20-60m)出现了埃克曼滚。在另一个高分辨率模拟中(用较小的区域进行)，Ekman卷与湍流动能增加有关，但垂直热通量相对较小。我们的结果将有助于解释现场观测和海洋驱动的冰架基础融化的参数。
The melt rate of Antarctic ice shelves is of key importance for rising sea levels and future climate scenarios. Recent observations beneath Larsen C Ice Shelf revealed an ocean boundary layer that was highly turbulent and raised questions on the effect of these rich flow dynamics on the ocean heat transfer and the ice shelf melt rate (Davis and Nicholls 2019). Directly motivated by the field observations, we have conducted large-eddy simulations (LES) to further examine the ocean boundary layer beneath Larsen C Ice Shelf. The LES was initialised with uniform temperature and salinity (T/S) and included a realistic tidal cycle and a small basal slope. A new parameterization based on Vreugdenhil and Taylor (2019) was applied at the top boundary to model near-wall turbulence and basal melting. The resulting vertical T/S profiles, melt rate and friction velocity matched well with the Larsen C Ice Shelf observations. The instantaneous melt rate varied strongly with the tidal cycle, with faster flow increasing the turbulence and mixing of heat towards the ice base. An Ekman layer formed beneath the ice base and, due to the strong vertical shear of the current, Ekman rolls appeared in the mixed layer and stratified region (depth ≈ 20–60m). In an additional high-resolution simulation (conducted with a smaller domain) the Ekman rolls were associated with increased turbulent kinetic energy, but a relatively small vertical heat flux. Our results will help with interpreting field observations and parameterizing the ocean-driven basal melting of ice shelves.
使用各向异性最小耗散模型对分层平面库埃特流进行大涡模拟
DOI：
10.17863/cam.32401
发表时间：
2018
期刊：
--
影响因子：
--
作者：
Vreugdenhil C
通讯作者：
Vreugdenhil C
冰架-海洋边界流内的剪切、稳定性和混合
影响因子：
3.5
作者：
Jenkins A
通讯作者：
Jenkins A
冰架下湍流边界层中融化驱动的双扩散通量的数值模拟
影响因子：
3.5
作者：
Middleton L
通讯作者：
Middleton L