STUDY ON THE FORMATION PROCESSES OF THE INTERMEDIATE AND BOTTOM MIXED LAYERS NEAR THE CONTINENTAL SHELF BREAK

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During 5 to 7 August, 1993 and during 4 to 7 August, 1994, temporal variations of current velocity and temperature by mooring arrays just above the sloping bottom with several current meters, temperature distribution with CTD and XBT cast, vertical distribution of the turbulent energy dissipation epsilon with MSP,and in 1994 temporal variation of the fine structure of temperature with thermistor-chain were obtained around the area near the continental shelf break in the East China Sea.Mooring current meters caught short time scale fluctuations which took place intermittently within the bottom mixed layr. These small scale fluctuations may be caused by instability due to shear flow in the stratified fluid, that is KH-instability. We can consider the instability must play an important role to form the bottom mixed layr. Small scale internal waves with frequencies near the Brunt-Vaisala frequency were also generated along with the small scale turbulent fluctuations.However, we could not detect an evidence of breaking of internal waves from the measurement of temporal variations of temperature fine structure near the bottom mixed layr with the thermistor-chain.The maximum value of epsilon obtained by MSP is about 10^<-3>cm^<2s>^<-3>. Time scale of turbulence which is estimated from the value of epsilon is about 3 hours for the turbulent energy of 10 cm^2s^<-2>. This may correspond that the small scale fluctuations measured from mooring system continued for a few hours in a thin layr.