Global mapping of diapycnal diffusivity in the deep ocean based on the results of expendable current profiler (XCP) surveys
Global mapping of diapycnal diffusivity in the deep ocean based on the results of expendable current profiler (XCP) surveys
复制标题
DOI：
10.1029/2005gl025218
复制
发表时间：
2006-02-15
影响因子：
5.2
通讯作者：
Niwa, Yoshihiro
中科院分区：
文献类型：
--
作者：
Hibiya, Toshiyuki;Nagasawa, Maki;Niwa, Yoshihiro
基于广泛的XCP调查在北太平洋的结果，我们首先研究的经验关系估计的diapycnal扩散在温跃层和数值预测，可用的能量密度的半日内潮（主要能源diapycnal扩散）在每个位置。通过将Gregg（1989）的参数化应用于XCP测量的水平速度的细尺度垂直切变，来估计透圈扩散率。接下来，数值预测的能量密度的半日内潮在每个经度和纬度在世界的海洋被纳入由此产生的经验关系，以获得全球分布的温跃层的diapycnal扩散率。该模式预测，强的横辐混合（混合热点）仅限于纬度在20度和30度之间的突出地形特征。
Based on the results of the extensive XCP surveys in the North Pacific, we first examine the empirical relationship between the estimated diapycnal diffusivity in the thermocline and the numerically predicted, available energy density of the semidiurnal internal tide (major energy source for diapycnal diffusivity) at each location. The diapycnal diffusivity is estimated by applying the parameterization of Gregg (1989) to the fine-scale vertical shear of horizontal velocity measured by XCP. Next, the numerically predicted energy density of the semidiurnal internal tide at each longitude and latitude in the world's oceans is incorporated into the resulting empirical relationship to obtain the global distribution of diapycnal diffusivity in the thermocline. This model predicts that strong diapycnal mixing (mixing hotspot) is limited to the prominent topographic features at latitudes between 20 degrees and 30 degrees.