758 



[CHAP. 22 



0.25 



CYCLES PER MINUTE 



Fig. 25. Internal waves observed off Mission Beach, California, 5-7 Aug., 1959. Top panel : 

 Vaisala's frequency as a function of depth. Second panel : mean spectra of isotherm 

 follower oscillations. Third panel : coherence R with horizontal line showing 95% 

 confidence level. Bottom panel : phase shift 0. Small dots : i?21 and 021- Large dots : 

 i?32 and 6>32. Open circles: R^i and 6>3i. Insert: Plan of observing positions 1, 2, 3. 

 Wave normals are incident at angles with respect to the lines connecting positions i, j. 



i 



I 



