Table 6- STATIONARY DEPTH CHANGE A OF THE ISOTHERMS 



IN THE UPPER 230 METERS, ITS FOURIER AMPLITUDE A^ ,f 



AND THE ANALYZED AMPLITUDE A^ OF THE RECORD ' 















Set 



A 



^o,st 



K 



1-3 



54.1 



17.3 



22.4 



2-4 



86.2 



27.5 



3.5.3 



3-5 



56.6 



18.1 



28.7 



4-6 



20.7 



6.6 



8.7 



6-8 



25.6 



8.2 



16.3 



7-9 



17.1 



5.4 



11.5 



8-10 



25.3 



8.0 



20.0 



9-11 



45.0 



14.4 



16.2 



10-12 



2.1 



0.7 



2.1 



11-13 



35.4 



11.3 



16.2 



DISCUSSION OF RESULTS 



Figures 12-21 show the analyzed amplitudes A„ . The dashed line 

 represents the supposed stationary amplitude distribution due to the inclination 

 of the isotherms. The general shape of the dashed line intersecting the minimum 

 values agrees approximately with a function that is propotional to 1''??. 



In order to determine the doppler shifts one must know the phase velocity, 

 c, and the direction of the internal waves. Since a hydrographic station was not 

 available for the time, the density distribution from STRANGER station 95 

 (<?S = 30°20.5'N, A=119°27'W; depth, 3840 m) was substituted. 



The phase velocities for the 1-4 modes are : 



c, = 2.19 msec \ 



Co= 1.20 msec' 



c. = 0.47 msec" 



Because the actual phase velocities in August 1961 may differ from these 

 values, it is not possible to attribute the higher modes to the peaks of the 

 computed spectra. 



The rules from which the direction of the internal tidal waves were 

 determined are demonstrated in figure 12. Here, one group of peaks appears in the 

 range between 24 houi-s and 7.2 hours, another beyond 5-5 hours. It is known 

 from the drift stations that the diurnal and semidiurnal tides are dominant in the 

 area under consideration. For this reason the first group of peaks are identified 

 as the modes of the diurnal internal tides. The first mode is thus assumed to 

 •appear at 18 hours, having been shifted from 25 hours. Using equation 26, phase 

 velocity c. = 2.19 m/sec"^ corresponding to the first mode, and ship velocity 



40 



