Direct observations of turbulent mixing in energetic ocean currents are fundamentally important to improving the understanding of stratified turbulence and the predictive capability of ocean models. In this study, we have selected an energetic region of the Western Indian Ocean to make simultaneous measurements of temperature and velocity to directly infer the geography of turbulent mixing on the east coast of South Africa. Direct measurements of the rate of turbulent kinetic energy dissipation, \(\epsilon\), were recorded by an autonomous underwater vehicle glider platform and vertical microstructure profiler (VMP). The glider was deployed in the Agulhas current in 2015 over a 200 km transect and measured approximately 250 vertical profiles of turbulent microstructure. Additional vertical profiles near the shelf were obtained from approximately 85 VMP casts during 2018 in a region where the powerful Agulhas current is formed and interacts with the shelf. VMP and glider data collected at Sodwana Bay and the Agulhas current showed evidence of elevated dissipation rates \(10^{-8}<\epsilon <10^{-6}\) Wkg\(^{-1}\). Our results indicate that in general turbulent mixing in the Agulhas is concentrated spatially in pancake-shaped patches. Ordinary Kriging was used to interpolate between consecutive profiles and showed that the horizontal scale of the turbulent patches was typically O(1 km) while the vertical scales of the patches ranged between 0.01 and 10 m.

直接观测高能洋流中的湍流混合对于提高对分层湍流的理解和海洋模型的预测能力至关重要。在这项研究中，我们选择了西印度洋的一个充满活力的区域来同时测量温度和速度，以直接推断南非东海岸的湍流混合地理。湍流动能耗散率的直接测量，\(\epsilon\)，由自主水下航行器滑翔机平台和垂直微观结构剖面仪 (VMP) 记录。该滑翔机于 2015 年部署在厄加勒斯海流中，跨越 200 公里的横断面，测量了大约 250 个湍流微观结构的垂直剖面。2018 年期间，在一个形成强大的厄加勒斯海流并与大陆架相互作用的地区，大约 85 个 VMP 模型获得了大陆架附近的其他垂直剖面。在索德瓦纳湾和厄加勒斯海流收集的 VMP 和滑翔机数据显示耗散率升高的证据\(10^{-8}<\epsilon <10^{-6}\)  Wkg \(^{-1}\). 我们的结果表明，一般而言，厄加勒斯的湍流混合在空间上集中在煎饼状斑块中。普通克里金法用于在连续剖面之间进行插值，结果表明湍流斑块的水平尺度通常为 O(1 km)，而斑块的垂直尺度范围在 0.01 和 10 m 之间。