The similar plot of power spectrum peak to background of 

 the deeper isotherm (fig. 9B) also shows more high values in a 

 midway zone to Hawaii. The most persistent significant values 

 occurred between 140 and 150°W where the frequency was 0. 15- 

 0.23 cycles per minute (cpm) or a wavelength of 0.7 to 0.4 miles. 

 However, in general no single frequency persists over great dis- 

 tances. There are, however, a number of peaks with ratios 

 greater than 1.6 all along the entire section. 



RECOMMENDATIONS 



1 . Continue development of the thermistor chain to improve the 

 quality, accuracy, and reliability of the data. 



2. Make detailed studies of the thermocline and its associated 

 internal waves by use of the chain. Include studies of the effects 

 on the thermocline of islands, shoals, coastal configurations, 

 tides, currents, upwelling, river runoff, water-mass boundaries, 

 storms, and seasons. Particularly, acquire more data on the di- 

 rection and speed of internal waves. 



3. Investigate the use of other sensors, in conjunction with 

 temperature on the thermistor chain, for current, sound velocity, 

 and salinity. 



23 



