Estimating the Eddy Viscosity Profile from Velocity Spirals in the Ekman Boundary Layer
Estimating the Eddy Viscosity Profile from Velocity Spirals in the Ekman Boundary Layer
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DOI：
10.1175/jtech-d-14-00090.1
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发表时间：
2015-04
影响因子：
2.2
通讯作者：
Y. Yoshikawa;T. Endoh
中科院分区：
文献类型：
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作者：
Y. Yoshikawa;T. Endoh
近海潮流引起的湍流混合在近岸和浅海环境中起着重要的作用。人们已经做了许多尝试来量化海底附近的湍流混合，例如用微结构剖面仪测量速度微结构，用声学多普勒水流剖面仪(ADCP)测量湍流雷诺应力。这项研究提出了一种替代方法，即用测量的速度螺旋线求解Ekman平衡方程来估计涡粘性剖面。本文描述了三种方案(方案1、方案2和方案3)，方案1和方案2在以前的研究中被使用，而方案3是本研究中新提出的。用理想涡粘性廓线模拟的速度螺旋线对三种方案的性能进行了测试，结果表明，方案2在随机测量误差较小时是有效的，而方案3在埃克曼平衡误差较小时是有效的。此外，还使用MEASURE...
AbstractTurbulent mixing induced by tidal currents near the sea bottom plays a key role in coastal and shallow sea environments. Many attempts have been made to quantify turbulent mixing near the seabed, such as velocity microstructure measurements with microstructure profilers and turbulent Reynolds stress measurements using acoustic Doppler current profilers (ADCPs). This study proposes an alternative method in which the Ekman balance equations are solved with measured velocity spirals to estimate the eddy viscosity profile. Three schemes (schemes 1, 2, and 3) are described in this paper; schemes 1 and 2 were used in previous studies, while scheme 3 is newly proposed in the present study. The performance of the three schemes was tested using velocity spirals simulated with an idealized eddy viscosity profile, showing that scheme 2 is useful if the random measurement errors are small, while scheme 3 is useful when the errors in the Ekman balance are small. The performance was also evaluated using measure...