Modelling the dynamics and thermodynamics of icebergs
Modelling the dynamics and thermodynamics of icebergs
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DOI：
10.1016/s0165-232x(97)00012-8
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发表时间：
1997-10-01
影响因子：
4.1
通讯作者：
Johnson, JA
中科院分区：
文献类型：
--
作者：
Bigg, GR;Wadley, MR;Johnson, JA
冰山对极地航运是一个重大的危险，而且，从水文学上讲，是大陆冰盖质量平衡的重要组成部分，同时为极地海洋提供主要的淡水输入。一些冰山轨迹的建模已经在过去进行，主要是在拉布拉多海，但在这里，我们提出了一个半球范围内的尝试，在北极和北大西洋的冰山运动模型。我们表明，在冰山运动的基本力平衡之间的水阻力和水平流，但与纯地转平衡只是后者的一个次要组成部分。冰山密度图基本上证明了主要的边界电流的影响，但我们表明，时间和规模的崩解从个人tiblion冰川是重要的变量，在确定最终的命运的冰山。最大的冰山永远不会离开北冰洋。所有的冰山模型都在发布日期后大约5年融化，尽管大多数冰山在第一年融化。在他们的一生中，大多数，但不是所有的冰山，推翻几次。我们的模型与有限的观测数据吻合得很好。因此，我们建议，冰山，无论是模拟和观察，可以利用以前很少使用的地球物理示踪剂。(C)1997年Elsevier Science B.V.
Icebergs are a significant hazard for polar shipping, and, geophysically, are significant components of the mass balance of continental ice sheets while providing major freshwater inputs to the polar oceans. Some modelling of iceberg trajectories has been undertaken in the past, principally in the Labrador Sea, but here we present a hemispheric-wide attempt to model iceberg motion in the Arctic and North Atlantic Oceans. We show that the basic force balance in iceberg motion is between water drag and water advection, but with the pure geostrophic balance being only a minor component of the latter. Iceberg density maps essentially demonstrate the effect of the major boundary currents but we show that the time and size of calving from individual tidewater glaciers are important variables in determining the ultimate fate of bergs. The biggest bergs never leave the Arctic Ocean. All modelled icebergs have melted after about 5 years from their release date, although most melt over the first year. During their lifetime most, but not all bergs, overturn several times. Our model shows good agreement with the limited observational data. We therefore suggest that icebergs, both modelled and observed, may be exploited as previously little-used geophysical tracers. (C) 1997 Elsevier Science B.V.