I ^ 48.5 W 



The 17 May SLAR survey, con- 

 ducted on the last day of the 

 experiment, provided the rrxjst 

 remarkable image (Figure C-7d). 

 It shows an eddy with a complex 

 shape interacting with the NAC. 



Along the southern boundary of 

 the eddy is a sawtooth-pattern 

 with a peak-to-peak separation of 

 35km and a height of 20km. As 

 on the other dates, not all of the 

 boundaries are clearly defined, 



Figure C-7 Digitized fronts 

 depicted in tlie SLAR Imagery 

 for: (c) 9 May; and (d) 17 May. 



particularly the western t)oundary. 

 As a result, it is difficult to estimate 

 the size of the eddy based solely 

 on the SLAR imagery; the best 

 size estimate is 160 by 80 km. 



The 17 May imagery gives no hint 

 of striations on the cold water side 

 of the front. This is the only date 

 on which this occurred. May 17 

 was also the only cloud-free day 

 during the three-week experiment. 

 An AVHRR image from the NOAA 

 9 satellite, taken 8 hours before 

 the SLAR image, shows an 

 excellent agreement of the frontal 

 boundaries (Figure C-8). In 

 addition, the SLAR boundaries are 

 as sharp as those seen on the IR 

 imagery, unlike the results re- 

 ported by LaViolette (1983). 



Surface-truth 



The SLAR imagery depicted a 

 series of boundaries with intricate 

 structure, nrwst of which cannot be 

 resolved by the coarsely spaced 

 oceanographic survey and the 

 tracks from a few buoys. This 

 section deals only with the clear- 

 est and largest features. 



First Oceanographic Survey 



Near surface temperatures from 

 the 26 April - 3 May survey (Figure 

 C-9) supports the interpretation of 

 the dari< areas in the 26 April 

 SLAR image as waters of NAC 

 origin. The SLAR-detected front 

 nearly coincides (Figure C-lOa) 

 with a sharp thermal front, repre- 

 sented in the figure as the 12°C 

 (chosen as an indication of water 

 of NAC origin) contour of sea 



61 



