:::

最新消息

:::

103/12/02 14:00 中山大學海洋科學系陳冠宇教授 演講

演講公告
張貼人:網站管理員公告日期:2014-11-26
 
演 講 公 告
 

講題:Internal Waves Generated in the Luzon Strait

 

主講人:陳冠宇 教授
 
    中山大學海洋科學系

 
時間:12月02日(星期二)下午2點
 

地點:中央大學科學一館S-325教室
 

摘要:
 
  Internal waves generated in the Luzon Strait are the source of internal waves observed in South China Sea (SCS). In a simulation without Kuroshio, formation of internal wave rays in the Luzon Strait can be easily observed based on baroclinic velocity in east-west direction. Therefore, to the west of Luzon Strait, internal waves propagate in the east-west direction. Oblique nonlinear interactions based on the Kadomtsev‐Petviashvili (KP) equation are extended to internal waves to explain why the wave amplitude does not decrease owing to the geometric spreading of the cylindrical wavefronts in the SCS. This resonance theory is used to explain a satellite image exhibiting special features, and it is proposed that wave arcs of different amplitude resonate, providing a mechanism for reinforcing a wave by boosting the amplitude.
 
  In another simulation with Kuroshio, internal waves also propagate in the north-south direction. This model is developed by Taiwan Ocean Research Institute for general oceanographic forecast. Numerical simulation shows internal wave rays propagate northward in the Kuroshio zone. To validate the model, some temperature instruments on Ocean Bottom Seismometers are used. These instruments are deployed by National Taiwan University at the bottom of deep ocean to the east of Taiwan. A comparison of the temperature disturbance and the simulated vertical displacement w*dt suggests the temperature oscillation is due to the up and down of fluid parcel which can be identified as internal waves. That is, the energy is spreaded over a wide range and some wave energy does not propagate to the east. Instead, part of the energy is brought northward and hence the internal wave propagating to the east is less concentrated. Thus, unlike the wave that propagates westward to Dongsha, the eastward wave does not form nonlinear internal waves and internal solitary waves.

 
最後修改時間:2014-11-26 AM 10:26

cron web_use_log