Anchor Station 4 



After observations at the drift stations, similar measurements were made 

 at an anchored station. The hydrographic data obtained are listed in table 3. 



Table 3. HYDROGRAPHIC DATA FOR STATION 4 

 Date: 3 December 1963 . Position: 32°04'N, 118°30'W. Depth: 330 meters. 



Depth (m) 



Temp. (°C) 



Salinity (%„) 



ot 



Accepted 

 1 dj . 10-6 

 p dz 







17.41 



33.18 



24.50 



0.00 



10 



17.41 



33.60 



24.38 



0.62 



20 



17.41 



33.64 



24.40 



14.95 



30 



17.38 



33.75 



24.50 



14.95 



50 



13.40 



33.44 



25.13 



13.66 



75 



12.04 



33.59 



25.51 



11.77 



100 



10.68 



33.72 



25.86 



6.47 



150 



9.67 



33.92 



26.19 



4.00 



200 



8.60 



33.96 



26.39 



4.51 



250 



7.94 



34.13 



26.63 



2.29 



300 



7.68 



34.13 



26.65 



0.67 



Chain records were obtained for Anchor Station 4 for the period from 0500 

 to 2400 hours on 3 December 1963. Fourier analysis of the 12-hour and 24-hour 

 harmonics produced the results given in table 4. The mean rms amplitudes for 

 the upper 200 meters are 4.0 meters and 9.4 meters for the diurnal and semidiur- 

 nal internal tides, respectively. 



Because of the shallowness of the station, records are available for the 

 entire upper half of the water. Therefore, it seems to be possible to compute the 

 contributions of the first to fourth modes to the observed amplitudes. 



Figures 8 A and B show the eigenfunction distribution for the first 

 through eleventh modes. The contributions of these modes were computed by 

 using equation 19. The 17°, 13°, 11°, and 9° isotherms were used for these 

 computations. The results for the first four modes are summarized in table 5. 

 Generally the second mode has much more influence than the other ones. This 

 computation is not exact because the measurements are not spaced over the 

 entire water column. 



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