Title page for etd-1010116-105312


[Back to Results | New Search]

URN etd-1010116-105312
Author Kuo-feng Chien
Author's Email Address No Public.
Statistics This thesis had been viewed 5537 times. Download 559 times.
Department Institute of Undersea Technology
Year 2016
Semester 1
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Ambient Noise Analysis of Internal Wave of Sand Dune Region in North South China Sea
Date of Defense 2016-10-31
Page Count 81
Keyword
  • North South China Sea
  • Internal Wave
  • Sand Dune
  • Breaking Wave Noise
  • Multiple Correlation
  • Vertical Directionality
  • Noise Notch
  • Abstract In recent years, internal wave of North South China Sea has become an important ocean research topic. The tidal energy from Luzon Ridge formed a huge nonlinear internal wave in deep ocean. This event dropped water column dramatically, the maximum isotherm downward shift can be 15.9 meters at 200 meter water depth in our observation. During the propagation of internal wave, the convergence of surface water can form a significant breaking wave strip with loud noise. Data used in this research came from Sand Dunes project of South China Sea of June 2014. Experimental site was located in sand dune region of upper continental slope of North South China Sea. When internal wave passed, strong current caused turbulence and strumming noises due to the existence of mooring structure. The correlation coefficient between breaking wave noise enhancement and amplitude of internal wave is 0.7. However, if measurement location was close to sea bed or sand dune region, the correlation would be declined. Multiple correlation shows that background noise would limit breaking wave noise contribution, and coefficient of determination among internal wave amplitude, noise enhancement and background noise level can be as high as 0.9. In the past, some researches suggested that noise notch might be related to internal wave, but acoustical mode coupling of internal wave might on the other hand diminish the notch. According to analysis of vertical directionality in this research, the energy of breaking wave noise of internal wave was not enough to form noise notch, and mode coupling may also prevent the formation of noise notch.
    Advisory Committee
  • Shiuh-Kuang Yang - chair
  • Linus Y.S. Chiu - co-chair
  • Ruey-Chang Wei - advisor
  • Files
  • etd-1010116-105312.pdf
  • Indicate in-campus at 1 year and off-campus access at 1 year.
    Date of Submission 2016-11-10

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys