Observation of Near-Inertial Internal Waves on the Continental Slope in the Northwestern S

Observation of Near-Inertial Internal Waves on the Continental Slope in the Northwestern South China

Sea

ZHENG Jie;TIAN Jiwei;LIANG Hui

【期刊名称】《中国海洋大学学报（英文版）》 【年(卷),期】2017(016)002

【摘要】Based on nearly 3 months of moored acoustic Doppler current profiler records on the continental slope in the northwestem South China Sea (SCS) in 2006,this study examines temporal and vertical characteristics of near-inertial internal waves (NIW).Rotary frequency spectrum indicates that motions in the near-inertial frequency are strongly

polarized,with

clockwise

(CW)

energy

exceeding

counterclockwise (CCW) by about a factor of 10.Wavelet analysis exhibits an energy peak exceeding the 95％ confidence level at the frequency of local inertial during the passage of typhoon Xangsane (24 September to 4 October).This elevated near-inertial kinetic energy (NIKE) event possesses about a 4 days delay correlation with the time integral of energy flux induced by typhoon,indicating an energy source of wind.Further analysis shows that the upward phase velocity of this event is 3.8 m h-1 approximately,corresponding to a vertical wavelength of about 125 m if not taking the redshift of local inertial frequency into account.Rotary vertical wavenumber spectrum exhibits the dominance