Fluctuation of acoustic modal amplitude and depth dependence due to internal waves and tide

We report experimental results of 2005 Yellow-Sea acoustic experiment on interaction of ocean internal waves. Broadband normal modal amplitude fluctuations and depth dependences due to internal waves and tide are considered. It is found amplitude fluctuations above 5 dB when nonlinear ocean internal waves（IW） are passing receiver array,and their depth dependences are well coincided with theoretical results,satisfying the differential curve of corresponding 1^st. normal modal function.The modal fluctuation amplitude due to M2 tide shows similar properties,however,the phase changes in IW and tide cases are significant different.Displacement of the modal function with respect to hydrophones is responsible for the former,however latter is determined by a composition of changes of the modal function and displacement of hydrophones.