Propagation of Topographic Rossby Waves in the Deep Basin of the South China Sea Based on Abyssal Current Observations
Propagation of Topographic Rossby Waves in the Deep Basin of the South China Sea Based on Abyssal Current Observations
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DOI：
10.1175/jpo-d-21-0051.1
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发表时间：
2021-06
影响因子：
3.5
通讯作者：
Hua Zheng;Xiao-hua Zhu;Chuanzheng Zhang;Ruixiang Zhao;Zenan Zhu;Zhao‐Jun Liu
中科院分区：
文献类型：
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作者：
Hua Zheng;Xiao-hua Zhu;Chuanzheng Zhang;Ruixiang Zhao;Zenan Zhu;Zhao‐Jun Liu
地形罗斯比波（trw）是在倾斜地形上水柱在位涡保持下穿越等深线时产生的振荡。基于2016 - 2019年的大尺度观测，首次在南海深海盆观测到近65 d的trw。trw以较大的波长（235 km）和相速度（3.6 km/天）向西传播，而较小的波长（80 km）和相速度（1.2 km/天）向阵列的西南方向传播。采用射线追踪模型对trw的能量来源和传播特征进行了识别。近65天trw的路径主要沿等深线移动，并有轻微的下坡传播。台风的能量来源可能是台湾西南海面涡旋的变化。近65天能量从台湾西南部向东北和西南方向传播的时间分别为~100 ~ 120天和~105天，对应的群速度分别为4.2 ~ 5.0和10.5 km/d。这表明trw在深海动力和深海洋流变化中起着重要作用，上层海洋的变化可能调节深海南海的季节内变化。
Topographic Rossby waves (TRWs) are oscillations generated on sloping topography when water columns travel across isobaths under potential vorticity conservation. Based on our large-scale observations from 2016 to 2019, near 65-day TRWs were first observed in the deep basin of the South China Sea (SCS). The TRWs propagated westward with a larger wavelength (235 km) and phase speed (3.6 km/day) in the north of the array and a smaller wavelength (80 km) and phase speed (1.2 km/day) toward the southwest of the array. The ray-tracing model was used to identify the energy source and propagation features of the TRWs. The paths of the near 65-day TRWs mainly followed the isobaths with a slightly downslope propagation. The possible energy source of the TRWs was the variance of surface eddies southwest of Taiwan. The near 65-day energy propagated from the southwest of Taiwan to the northeast and southwest of the array over ~100–120 and ~105 days, respectively, corresponding to a group velocity of 4.2–5.0 and 10.5 km/day, respectively. This suggests that TRWs play an important role in deep-ocean dynamics and deep current variation, and upper ocean variance may adjust the intraseasonal variability in the deep SCS.