Submesoscale Sea Ice-Ocean Interactions in Marginal Ice Zones
Submesoscale Sea Ice-Ocean Interactions in Marginal Ice Zones
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DOI：
10.1002/2017jc012895
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发表时间：
2017-12-01
影响因子：
3.6
通讯作者：
Thompson, Andrew F.
中科院分区：
文献类型：
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作者：
Manucharyan, Georgy E.;Thompson, Andrew F.
海洋涡旋、锋面和冰丝的特征通常通过海冰密集度的卫星图像和冰系剖面仪或冰下滑翔机的现场观测在边缘冰区（MIZ）内观察到。然而，局部和间歇性的海冰加热和海洋涡旋平流目前没有考虑到气候模式，可能有助于他们的偏见和错误的海冰预测。在这里，我们探讨机械海冰与底层的次中尺度海洋湍流的相互作用。我们证明了储存在融水锋中的势能的释放可以导致沿着沿着MIZ的能量亚中尺度运动，其空间尺度为O（10 km），Rossby数为O（1）。在低风速条件下，气旋漩涡和细丝有效地捕获海冰，并将其平流到温暖的海洋表面沃茨，在那里它可以有效地融化。海冰质量和热量的水平涡动扩散率可达O（200 m（2）s（-1））。次中尺度海洋变率也会引起较大的垂直速度（10 m d（-1）量级），这会将相对温暖的次表层沃茨带入混合层。海洋-海冰热通量位于气旋涡旋和细丝上方，达到约100 W m（-2）。我们推测，这些次中尺度驱动的间歇性通量的热量和海冰可以有助于MIZ的季节性演变。随着全球气候变暖和北冰洋海冰厚度减少，中尺度海冰-海洋过程将日益突出。
Signatures of ocean eddies, fronts, and filaments are commonly observed within marginal ice zones (MIZs) from satellite images of sea ice concentration, and in situ observations via ice-tethered profilers or underice gliders. However, localized and intermittent sea ice heating and advection by ocean eddies are currently not accounted for in climate models and may contribute to their biases and errors in sea ice forecasts. Here, we explore mechanical sea ice interactions with underlying submesoscale ocean turbulence. We demonstrate that the release of potential energy stored in meltwater fronts can lead to energetic submesoscale motions along MIZs with spatial scales O(10 km) and Rossby numbers O(1). In low-wind conditions, cyclonic eddies and filaments efficiently trap the sea ice and advect it over warmer surface ocean waters where it can effectively melt. The horizontal eddy diffusivity of sea ice mass and heat across the MIZ can reach O(200 m(2) s(-1)). Submesoscale ocean variability also induces large vertical velocities (order 10 m d(-1)) that can bring relatively warm subsurface waters into the mixed layer. The ocean-sea ice heat fluxes are localized over cyclonic eddies and filaments reaching about 100 W m(-2). We speculate that these submesoscale-driven intermittent fluxes of heat and sea ice can contribute to the seasonal evolution of MIZs. With the continuing global warming and sea ice thickness reduction in the Arctic Ocean, submesoscale sea ice-ocean processes are expected to become increasingly prominent.