Temporal and Regional Variation of Sea Ice Draft And Coverage in the Weddell Sea Obtained from Upward Looking Sonars
Temporal and Regional Variation of Sea Ice Draft And Coverage in the Weddell Sea Obtained from Upward Looking Sonars
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从上视声纳获得的威德尔海海冰吃水和覆盖范围的时间和区域变化
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
E. Fahrbach
中科院分区：
文献类型：
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作者：
V. Strass;E. Fahrbach
摘要：在1990年和1994年之间，在威德尔海的六个地点，用停泊的上视声纳（ULS）获得了长达两年的冰吃水和覆盖率时间序列。位于南极半岛顶端和Kapp Norvegia之间的六个系泊点覆盖了进出南部威德尔海的水流。本文分析了威德尔海冰吃水分布的时间和区域变化，并利用这些变化估计了热力生长和形变对威德尔海冰吃水分布的相对贡献，结果表明，在涡旋中心冰吃水有明显的年周期变化，而在边界区，特别是在东部，冰吃水的时间变化不太规律。平均冰吃水在威德尔环流中心0.8 m、东部流入2.2 m和西部流出2.8 m之间变化。与此相反，冰吃水的模态在环流中心最高（0.7m），在边界区最低（0.2m）。在西部外流中，变形冰的平流导致1.1米处的第二个最大值。在威德尔环流期间，吃水小于1米的冰转变为较厚的冰;主要转变发生在吃水0.2米到1.2米之间。得出的结论是，变形（漂流和脊）的贡献最小的30%，形成的总冰量在威德尔海的内部和最小的50%，在边界地区。
Abstract: Up to two years long time series of ice draft and coverage were obtained between 1990 and 1994with moored Upward Looking Sonars (ULSs) at six locations in the Weddell Sea. The six mooring locations,between the tip of the Antarctic Peninsula and Kapp Norvegia, cover the flow into and out of the southernWeddell Sea. The measurements are analyzed for the temporal and regional variations, and used to estimatethe relative contribution of thermodynamic growth and deformation to the ice draft distribution in the WeddellSea.Whereas the ice draft in the gyre centre undergoes a distinct annual cycle, temporal changes occur ratherirregularly in the boundary regions, especially in the east. The mean ice draft varies between 0.8 m in the centralWeddell Gyre, 2.2 m in the eastern inflow and 2.8 m in the western outflow. In opposition to this, the mode of theice draft is highest (0.7 m) in the gyre centre and lowest (0.2 m) in the boundary regions. In the western outflow asecond maximum at 1.1 m results from advection of deformed ice. During circulation with the Weddell Gyremainly ice with a draft of less than 1 m is transformed into thicker ice; the major transformation occurs from draftsof 0.2 m to drafts of 1.2 m. It is concluded that deformation (rafting and ridging) contributes a minimum of 30 % tothe total amount of ice formed in the inner Weddell Sea and a minimum of 50 % in the boundary regions.