25 June 1958 



The thermocline on 25 June (fig. 5A-B) was rather strong during the first half- 

 hour, apparently descended, and became weaker in the upper 35 feet toward the 

 end of the day's record. The vertical oscillations and slicks were quite numerous 

 in the first half of the day, becoming less regular towards the second half. There 

 were 22 small slicks in a period of 2 hours and 54 minutes. They occurred very 

 close to each other and nearly all were associated with individual oscillations in 

 the thermocline. Where there were more oscillations, there were more slicks; 

 however, their orientation with respect to the ascent and descent of the thermo- 

 cline was less consistent than on most of the other days. In nearly all cases, one 

 slick was associated with one depression or crest. There were only one or two 

 exceptions in which a slick was observed and a depression was not definitely as- 

 sociated with it. 



26 June 1958 



The thermocline on 26 June (fig. 6A-B) was relatively deep and strong, and its 

 top was about 15 to 25 feet below the surface. There were many small irregular- 

 ities in the thermocline. On this day, the wind was blowing from the southwest 

 to south. Consequently, although many slicks were recorded, they were all being 

 broken up into patches, and none were distinct glassy streaks. The first four 

 slicks were associated with small depressions, followed by one in a broad trough. 

 The next was over an irregular oscillating thermocline. The second half of the 

 record, too, was made up of relatively small oscillations (about 5 feet and 5 min- 

 utes). The second and third slicks in this half appeared over a small lowering of 

 the thermocline. The next three were associated with a lowering of the thermo- 

 cline most of which descended below 35 feet at 1355. The last slick was still 

 broken and occurred at a time when the thermocline was descending. This ir- 

 regular relation of slicks to oscillations in the thermocline was caused by the 

 large angle between the direction of the wind and that of the internal waves. 



8 July 1958 



On 8 July (fig. 7) the 1° isotherms were a little more compact, that is, the 

 vertical temperature gradient was relatively stronger and nearer the surface than 

 on some of the previous days. The isotherms fluctuated rather widely throughout 

 the day, and at no time was the thermocline at a constant level. The first slick 

 occurred just before a trough and on the steepest part of the descent. The second 

 and third slicks were likewise associated with a descending isotherm. These were 

 followed 20 minutes later by a series of nearly equally spaced, vertical oscillations 

 in the thermocline. Most oscillations had rather weak slicks associated with them. 

 Some did not fall exactly on the steepest part of the waves, but instead occurred 

 higher up, almost at the crest. Finally, there was a slick near the end of the day's 

 record, and a depression appeared to be starting as the record ended. 



9 July 1958 



On 9 July (fig. 8) the thermocline was near the surface but rather weak com- 

 pared to other days. Only four slicks were observed in a period of over IV2 hours. 

 The first slick occurred on the descending slope. The second slick, after a period 

 of relative inactivity in the thermocline, also occurred on the descending slope. 

 The third slick, too, was over a descending slope. The last one of this day was on 

 a gradual descending slope. 



10 



