at about 1730 Z and the wind at the sMp shifted to norfh.-north.westerly 

 (fig, 5.2b). 



Tlie principal low of the area at this time was centered east of New= 

 foundland and was moving eastward. The R. V. ATLANTIS was moved east- 

 ward to 39°N 65°W during the 24t3i and 25th to retain moderate to fresh 

 breezes. 



On the 25th, the day the aerial stereo-photographs were taken, the 

 wind was north.=northwest, Beaufort force 5 at 1230 Z (fig, 5.2c). diminish- 

 ing to force 4 by 1830 (fig. 5. 2d). The duration of wind up to the time of 

 the wave observations was from 17 1/2 to 26 hours, making the test period 

 the longest period of consistent force and direction for the cruise, ,, 



For the entire period from October 20th to the 25th there appears to 

 have been little or no possibility of a. contribution to the waves at the ship 

 by wind fields in other parts of the North Atlantic. Therefore, the ship 

 vf^.s essentially in the generating surea at all times and no swell should be 

 recorded. 



Discussion of Predicted and Observed Wave Conditions 



The first system with the potential of generating the required wave 

 height appeared during 20 and 21 October. The prediction was for the de- 

 velopment of waves 12 feet in height. The R. V. ATLANTIS reported 12 

 feet significant height at 20 1300 Z and was the maximum reported for this 

 storn>-j'wave heights ranged from 9.5 to 12 feet during the day. Although 



sea cQnditions were ideal, low ceilings with rain and accompanying poor 



38 



