CONTENTS 



Page 



INTRODUCTION 1 



Notes on Data 1 



The Bathythermogram 1 



Reliability of the Bathythermograph 3 



Mean Level 5 



Internal Waves 5 



THEORY 10 



Mixing 10 



Instability Mixing Due to Advection 10 



Instability Mixing Due to Density Increase 12 



Mixing Due to Permanent Convergence or Divergence lU 



Mechanical Mixing l6 



Decay of the Mixed Layer 19 



PROCEDURE 23 



Determination of the Mixing Parameter 23 



Wave Parameters 25 



Stability 25 



7] Curves 29 



Convergence and Divergence 30 



h Curves 52 



Salinity Gradient 53 



Weak Thermocline 57 



Variation of Thermocline Depth With Latitude 59 



PRACTICAL PREDICTION OF THE THERMOCLINE DEPTH 59 



Verification 59 



Means of Prediction 59 



Determination of the Stability Index 6l 



Prediction of Mixed-Layer Decay and Associated Thermocline 



Depth 66 



Persistence 67 



Examples of Prediction 68 



Approximation 71 



Error Due to Wind Evaluation and Decrease of Error 



With Increasing Wind 71 



Error Due to Wind Evaluation and Decrease of Error 



With Increasing At 71 



Error Due to Stability Index Evaluation 72 



Error Due to Type of Current Field 72 



