Modeling ice shelf water overflow and bottom water formation in the southern Weddell Sea
Modeling ice shelf water overflow and bottom water formation in the southern Weddell Sea
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DOI：
10.1029/2009jc005841
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发表时间：
2010-10
影响因子：
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通讯作者：
Y. Matsumura;H. Hasumi
中科院分区：
文献类型：
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作者：
Y. Matsumura;H. Hasumi
通过高分辨率数值实验研究了威德尔海南部菲奇纳坳陷溢出的冰架水（ISW）下降和由此产生的威德尔海底水（WSBW）生产。模型再现了在36°W附近与海底脊相互作用的部分ISW。在Filchner坳陷出口附近发育的斜压不稳定波导致了ISW的间歇性流出，ISW源致密水的间歇性通过引起了脊东侧6 d周期的速度振荡，这与系泊资料吻合较好。脊的存在诱导了两种不同的机制来跨等深线输送源自isw的致密水：在脊东侧的强下坡流和由涡流产生的近海输送，当重力流绕脊尖端绕行时，就会产生涡流，穿过脊西的广阔区域。在一个从状态方程中去除热压性的敏感性实验中，在3000 m深度以下几乎没有isw源水的输运。由于isw源致密水在模型域中的下降，WSBW的产率约为0.15 Sv。
[1] Descent of Ice Shelf Water (ISW) overflowed from the Filchner Depression in the southern Weddell Sea and consequent Weddell Sea Bottom Water (WSBW) production is investigated through high resolution numerical experiments. The model reproduces the part of ISW which interacts with the submarine ridge near 36°W. The baroclinic instability wave developed near the exit of the Filchner Depression leads to intermittent outflow of ISW, and the intermittent passage of ISW-origin dense water induces 6-day period oscillation of velocity at the east side of the ridge which coincides well with mooring data. The existence of the ridge induces two different mechanisms for cross-isobath transport of the ISW-origin dense water: a strong downslope current at the east side of the ridge and offshore transport by eddies, which are generated when a gravity current makes a detour around the tip of the ridge, over a wide region to the west of the ridge. In a sensitivity experiment where thermobaricity is removed from the equation of state, there is almost no transport of the ISW-origin water below 3000 m depth. WSBW production rate as a result of descent of the ISW-origin dense water in the model domain is about ∼0.15 Sv.