A High-Resolution Acoustic Doppler Profiler (HR-ADP), deployed at about 8.5 m depth in Lake Soppensee (Switzerland), observed mean velocities, shear, and internal waves over a depth range of about 4 m. The results suggest that, in spite of maximum velocities less than 15 mm/s, there is shear-induced internal wave generation and mixing around the thermocline. In particular, we observe enhanced internal waves underneath the mixed layer at frequencies bounded by the local buoyancy frequency, and alayer, 0.5-m thick, of critical Richardson's number at the base of the mixed layer.The HR-ADP is a pulse-to-pulse coherent Doppler sonar which uses a new, more robust means of signal processing to obtain velocity. Based on the noise spectrum, we conclude the measurement uncertainty in this experiment ranges from 0.3 to 1 mm/s.
展开▼
机译：高分辨率的声学多普勒分析器（HR-ADP），在Soppensee湖（瑞士）的约8.5米深度，观察到的平均速度，剪切和内部波在约4米的深度范围内。结果表明，尽管最大速度小于15毫米/秒，但剪切诱导的内部波产生并在热量下混合。特别地，我们观察由局部浮力频率界定的频率下的混合层下方的增强的内部波，Alayer，0.5米厚，在混合层的基础上的关键理查森的数量。HR-ADP是脉冲到 - 使用一种使用新的更强大的信号处理方法来获得速度的相干多普勒声纳。基于噪声光谱，我们在该实验中得出的测量不确定性范围为0.3至1 mm / s。
展开▼
