Numerical simulation of the Filchner overflow
Numerical simulation of the Filchner overflow
复制标题
Filchner 溢出的数值模拟
DOI：
10.1029/2008jc005013
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发表时间：
2009
影响因子：
--
通讯作者：
D. Feltham
中科院分区：
文献类型：
--
作者：
A. Wilchinsky;D. Feltham
冰架水（ISW）的羽流流入威德尔海菲尔希纳岩床有助于南极底层水的形成。Filchner溢出使用流体静力学，原始方程三维海洋模型与0.5-2 Sv ISW以上的Filchner窗台涌入模拟。在0.5和1 Sv的流入量下，发现与系泊温度观测的最佳拟合，低于基于稀疏系泊速度的先前估计值1.6 +/- 0.5 Sv。羽流首先向北移动越过大陆架，然后转向西，沿着大陆架断裂处的斜坡，在那里它分裂成亚羽流和圆顶，其中一些然后向下移动。其他亚羽流进入东部海底脊，并以混乱的方式沿着脊下坡传播。下一个，西脊是由羽通过几个路径跨越。尽管与观测数据有一些差异，该模型再现了流动的许多属性。特别是，我们认为，观测所示的时间变异性在很大程度上可以归因于不稳定的流动结构，温度波动是由过去的系泊圆顶的运动。我们的敏感性研究表明，虽然热压性发挥了作用，其影响是小的流量考虑。平滑的山脊表明，它们的存在强烈影响了山脊周围的羽流形状。底部阻力或粘性的增加导致速度减慢，从而使羽流变厚和变宽。
The plume of Ice Shelf Water (ISW) flowing into the Weddell Sea over the Filchner sill contributes to the formation of Antarctic Bottom Water. The Filchner overflow is simulated using a hydrostatic, primitive equation three-dimensional ocean model with a 0.5-2 Sv ISW influx above the Filchner sill. The best fit to mooring temperature observations is found with influxes of 0.5 and 1 Sv, below a previous estimate of 1.6 +/- 0.5 Sv based on sparse mooring velocities. The plume first moves north over the continental shelf, and then turns west, along slope of the continental shelf break where it breaks up into subplumes and domes, some of which then move downslope. Other subplumes run into the eastern submarine ridge and propagate along the ridge downslope in a chaotic manner. The next, western ridge is crossed by the plume through several paths. Despite a number of discrepancies with observational data, the model reproduces many attributes of the flow. In particular, we argue that the temporal variability shown by the observations can largely be attributed to the unstable structure of the flow, where the temperature fluctuations are determined by the motion of the domes past the moorings. Our sensitivity studies show that while thermobaricity plays a role, its effect is small for the flows considered. Smoothing the ridges out demonstrate that their presence strongly affects the plume shape around the ridges. An increase in the bottom drag or viscosity leads to slowing down, and hence thickening and widening of the plume.