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2014/12/02 14:00 Prof. Guan-Yu Chen（Department of Oceanography, NSYSU）
Seminar
Poster： ╱ Post date：2014-11-26NCU IHOS Seminar Announcemnet
Speaker：Prof. Guan-Yu Chen
Place：S-325, Science Building 1
Abstract：
Title：Internal Waves Generated in the Luzon Strait
Speaker：Prof. Guan-Yu Chen
Department of Oceanography, NSYSU
Time：12/02（Tue.）14：00
Place：S-325, Science Building 1
Abstract：
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.
Last modification time：2014-11-26 AM 10:26
