Temporal Variability of Diapycnal Mixing in Shag Rocks Passage
Temporal Variability of Diapycnal Mixing in Shag Rocks Passage
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DOI：
10.1175/2011jpo4573.1
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发表时间：
2012-03
影响因子：
3.5
通讯作者：
G. Damerell;K. Heywood;D. Stevens;A. N. Garabato
中科院分区：
文献类型：
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作者：
G. Damerell;K. Heywood;D. Stevens;A. N. Garabato
海洋表层混合速率具有很大的空间变异性，但对时间变异性的研究较少。本文给出了一种从系泊声学多普勒流速剖面仪(ADCP)速度切变剖面计算昼夜扩散系数的方法。根据停泊在北斯科舍海脊(南大洋)Shag Rock Passage中2400米深、海底600米处的LongRanger ADCP获取的数据，提供了18个月的扩散率时间序列。极锋被限制通过这条通道，而强流和复杂的地形预计将导致增强混合。由ADCP切变降低得出的沙岩航道扩散系数的空间分布与同类地区公布的值一致，在海底附近扩散系数可能高达90×10−4m2 S−1，而在远离地形的地区则降至预期的本底水平~0.10×10−4m2 S−1。那个.。
AbstractDiapycnal mixing rates in the oceans have been shown to have a great deal of spatial variability, but the temporal variability has been little studied. Here results are presented from a method developed to calculate diapycnal diffusivity from moored acoustic Doppler current profiler (ADCP) velocity shear profiles. An 18-month time series of diffusivity is presented from data taken by a LongRanger ADCP moored at 2400-m depth, 600 m above the seafloor, in Shag Rocks Passage, a deep passage in the North Scotia Ridge (Southern Ocean). The Polar Front is constrained to pass through this passage, and the strong currents and complex topography are expected to result in enhanced mixing. The spatial distribution of diffusivity in Shag Rocks Passage deduced from lowered ADCP shear is consistent with published values for similar regions, with diffusivity possibly as large as 90 × 10−4 m2 s−1 near the seafloor, decreasing to the expected background level of ~0.1 × 10−4 m2 s−1 in areas away from topography. Th...