Near‐inertial internal waves (NIWs) in the abyssal Yamato and Tsushima Basins of the Japan Sea (East Sea) were investigated using data from a moored acoustic Doppler current profiler (ADCP) and single‐point current meters. The NIW events with duration of 3–5 days were observed intermittently in both basins. In particular, an active NIW event occurred below 2475 m in the Yamato Basin during May 12–16, 2014. This was followed by the upward propagation of a wave packet from 2475 to 950 m. The near‐inertial flows (1.07f) during the event exhibited a vertically coherent phase and intensification with depth by a factor of 1.5 from 2475 to 2635 m. The near‐inertial flows (1.05f) in the Tsushima Basin also showed a vertically coherent phase and intensification with depth, although the amplitude of the flow exhibited a mid‐depth maximum rather than monotonic intensification. As a possible explanation of the observed flow characteristics, the superposition of downward‐propagating NIWs that can be excited by a strong wind event and upward‐propagating NIWs that bounced off the seabed was examined. The time series of the Richardson number based on the observed shear showed sporadic unstable conditions during the initial stage of the NIW event during May 2014 in the Yamato Basin. In addition, relatively small values of Richardson number were observed over the range of 2475–2635 m during the period of active NIWs. This suggests the promotion of vertical mixing in the deep sea during significant NIW events.

中文翻译：

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在日本海（东海）的深海大和盆地和对马盆地中，由于近惯性内波的叠加导致流量增强

利用系泊声多普勒电流剖面仪（ADCP）和单点电流计的数据，对日本海（东海）深海大和和对马盆地的近惯性内波（NIW）进行了研究。在两个盆地中间歇性地观察到了持续时间为3-5天的NIW事件。特别是，2014年5月12日至16日在大和盆地2475 m以下发生了活跃的NIW事件。随后波包从2475向上传播到950 m。事件期间的近惯性流（1.07 f）在2475至2635 m范围内表现出垂直相干相位和深度增强1.5倍。近惯性流（1.05 f对马盆地的）也显示出垂直连贯的相位并随深度而增强，尽管水流的振幅表现出了中深度的最大值而不是单调的强度。为了对观测到的流动特性做出可能的解释，研究了可被强风事件激发的向下传播的NIW与从海底弹起的向上传播的NIW的叠加。基于观测到的剪切力的理查森数的时间序列显示，2014年5月在大和盆地NIW事件的初始阶段出现了零星的不稳定条件。此外，在活跃的NIW期间，在2475-2635 m的范围内观察到了相对较小的Richardson值。这表明在重要的NIW事件期间，深海中的垂直混合得到了促进。