...
首页> 外文期刊>Journal of physical oceanography >Shear Instability in Internal Solitary Waves in the Northern South China Sea Induced by Multiscale Background Processes
【24h】

Shear Instability in Internal Solitary Waves in the Northern South China Sea Induced by Multiscale Background Processes

机译:Shear Instability in Internal Solitary Waves in the Northern South China Sea Induced by Multiscale Background Processes

获取原文
获取原文并翻译 | 示例
           

摘要

Instability within internal solitary waves (ISWs), featured by temperature inversions with vertical lengths of dozens of meters and current reversals in the upper shoreward velocity layer, was observed in the northern South China Sea at a water depth of 982 m by using mooring measurements between June 2017 and May 2018. Regions of shear instability satisfying Ri < 1/4 were found within those unstable ISWs, and some large ISWs were even possibly in the breaking state, indicated by the ratio of L-x (wave width satisfying Ri < 1/4) to lambda(eta/2) (wavelength at half amplitude) larger than 0.86. Wave stability analyses revealed that the observed wave shear instability was induced by strong background current shear associated with multiscale dynamic processes, which greatly strengthened wave shear by introducing sharp perturbations to the fine-scale vertical structures of ISWs. During the observational period, wave shear instability was strong in summer (July-September) while weak in winter (January-March). Sensitivity experiments revealed that the observed shear instability was prone to be triggered within large ISWs by the background current shear and sensitive to the pycnocline depth in the background stratification. However, shear instability within ISWs was observed to be promoted during mid-January, as the near-inertial waves trapped inside an anticyclonic eddy resulted in enhanced background current shear between 150 and 300 m. This work emphasizes the notable impacts of multiscale background processes on ISWs in the oceans.

著录项

获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号