Hydrographic structure in association with deep boundary current in the north of the Shikoku Basin
Hydrographic structure in association with deep boundary current in the north of the Shikoku Basin
复制标题
四国盆地北部深边界流与水文结构
DOI：
10.1007/bf02236524
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发表时间：
1995
影响因子：
2.3
通讯作者：
K. Taira
中科院分区：
文献类型：
--
作者：
M. Fukasawa;T. Teramoto;K. Taira
在四国盆地北部收集了高质量的CTD数据，在那里通过直流测量观测到了深海边界流。对水文资料的分析表明：1.与周围水域相比，九州-帕劳海脊的大陆架脚趾和东侧上方存在较冷和较咸的水(较重的水)，预计存在深海边界流。较重的水的水平范围约为50公里。2.较重的水从海底起的垂直尺度为2000米，与热风切变有关，热风切变增强了流向深渊左侧南开海槽(位于四国盆地北端的海槽)的一个分量。在约2500米深处的假设“无运动水平”给出了地转学估计的海流与直接测量的海流很好的一致性。与较冷和较高盐度的水有关的体积输送估计在Shiono-Misaki附近约2 Sv，其中可能包括南开海槽上方的一个再循环。这大约是四国盆地内部通过行星涡度的伸展项和纬度变化之间的涡度平衡估计的运输量的两倍。
High quality CTD data were collected in the north of the Shikoku Basin where an abyssal boundary current has been observed through direct current measurements. Analyses of hydrographic data showed:1.Colder and saltier water (heavier water) compared to surrounding waters is found above the continental shelf-toe and the eastern flank of the Kyushu-Palau Ridge where the existence of the abyssal boundary current has been expected. The heavier water has a horizontal extent of about 50 km.2.The heavier water has the vertical scale of 2000 m from the sea bottom, and is associated with a thermal wind shear which enhances a component of the flow toward a direction looking the Nankai Trough (a trough located along the northern end of the Shikoku Basin) to the left in the abyss. The assumed “level of no motion” at about 2500 m depth gives the geostrophically estimated current in a good agreement with the directly measured current.A volume transport associated with the colder and higher salinity water is estimated to be about 2 Sv off Cape Shiono-misaki which may include a recirculation above the Nankai Trough. This is about twice of the transport estimated in the interior of the Shikoku Basin through a vorticity balance between the stretching term and latitudinal variation of the planetary vorticity.