The effects of tides on the water mass mixing and sea ice in the Arctic Ocean
The effects of tides on the water mass mixing and sea ice in the Arctic Ocean
复制标题
DOI：
10.1002/2014jc010310
复制
发表时间：
2015-10
影响因子：
--
通讯作者：
M. Luneva;Y. Aksenov;J. Harle;J. Holt
中科院分区：
文献类型：
--
作者：
M. Luneva;Y. Aksenov;J. Harle;J. Holt
在这项研究中，我们使用一个新的泛北极海冰-海洋耦合模式来研究潮汐对海冰和水团混合的影响。进行了两次30年的模拟：一次有显式分解的潮汐，另一次没有任何潮汐动力学。我们发现，在过去的十年里，潮汐导致了∼海冰体积减少了15%，盐度重新分布，在潮汐平均比没有潮汐的情况下，∼的实际盐度单位高出1.0-1.8PSU。两种模式的冰量变化趋势也不同，无潮汐的−为2.09×103km~3/十年，有潮汐的−为2.49×103km~3/十年，后者更接近于PIOMAS模式中−2.58×103km~3/十年的趋势，它吸收了海温和冰的浓度。潮汐相互作用的三个机制似乎是重要的：(A)内水潮流的斜压顺时针旋转分量产生的强剪应力；(B)更厚的次表层冰洋和海底边界层；(C)通过加强底部Ekman抽水和在粗糙的海底地形上拉伸相对涡度，加强等长线的准稳定垂直运动(∼50%)。这些效应的结合导致温暖的大西洋水被卷进更冷、更新鲜的表面水域，支持了上面的冰的融化。
In this study, we use a novel pan-Arctic sea ice-ocean coupled model to examine the effects of tides on sea ice and the mixing of water masses. Two 30 year simulations were performed: one with explicitly resolved tides and the other without any tidal dynamics. We find that the tides are responsible for a ∼15% reduction in the volume of sea ice during the last decade and a redistribution of salinity, with surface salinity in the case with tides being on average ∼1.0–1.8 practical salinity units (PSU) higher than without tides. The ice volume trend in the two simulations also differs: −2.09 × 103 km3/decade without tides and −2.49 × 103 km3/decade with tides, the latter being closer to the trend of −2.58 × 103 km3/decade in the PIOMAS model, which assimilates SST and ice concentration. The three following mechanisms of tidal interaction appear to be significant: (a) strong shear stresses generated by the baroclinic clockwise rotating component of tidal currents in the interior waters; (b) thicker subsurface ice-ocean and bottom boundary layers; and (c) intensification of quasi-steady vertical motions of isopycnals (by ∼50%) through enhanced bottom Ekman pumping and stretching of relative vorticity over rough bottom topography. The combination of these effects leads to entrainment of warm Atlantic Waters into the colder and fresher surface waters, supporting the melting of the overlying ice.