【Title】 Arrival time fluctuation of higher order normal modes caused by solitary internal waves

【Author】LI Zhenglin~(1,3) ZHANG Renhe~1 Mohsen Badiey~2 Jing Luo~2 (1 State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences Beijing 100190) (2 College of Marine and Earth Studies,University of Delaware Newark,Delaware 19716) (3 Haikou Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences Haikou 570105)

【Abstract】The sensitivities of the normal modes arrival time to solitary internal waves(IWs) are analyzed by using the SW06 environments.Simulation results show that the arrival time of mode 1 is relatively stable.But,there are some higher-order normal modes which arrive earlier than mode 1,and fluctuate with the appearance of solitary IWs.Explanation of the phenomenon is given based on ray theory.It is shown that,when thermocline falls down to some depths,those higher-order modes with a group of definite grazing angles mainly propagate above the thermocline and arrive earlier.