Depth, 



m 







Temperature Difference, °C 







4C 



7C 



8C 



IOC 



15C 



18C 



19C 



200 



0.37 



- 



-0.06 



- 



-0.07 



-0.13 



- 



250 



0.14 



- 



0.03 



- 



0.07 



0.20 



- 



300 



0.30 



- 



0.17 



- 



0.14 



0.25 



- 



400 



0.08 



- 



-0.13 



- 



-0.11 



-0.11 



- 



500 



0.01 



- 



-0.06 



- 



-0.27 



- 



- 



600 



0.05 



- 



- 



- 



-0.31 



- 



- 



800 



0.03 



- 



- 



- 



-0.23 



- 



- 



1000 



- 



- 



- 



- 



-0.22 



- 



- 



1200 



- 



- 



- 



- 



-0.15 



- 



- 



1500 



- 



- 



- 



- 



- 



- 



- 



Depth of first 

 "glitch," m 



872 



105 



588 



55 



1400 



436 



90 



Table 43. Comparison of 1830-m RAPLOC/DEEPTOW XBT profiles classified 

 as partial successes with average CTD/SV temperatures. 



than the other six profiles and XBT 4F recorded temperatures consistently higher than 

 the other profiles over the depth interval from 400 to 800 m. These seven profiles were 

 made at widely spaced time intervals over a 10-day period. Since this area is known to 

 contain warm and cold water masses, or eddies, such variations in temperature are not 

 unexpected. Thus, on the basis of information available, there is no reason to question the 

 vahdity of seven of the eight profiles.* 



In summary, of a total of 26 1830-m XBT profiles, 10 (38.5%) were classified as 

 successes; eight (30.8%) as catastrophic failures; seven (26.9%) as partial successes; and one 

 exceeded the cahbration correction of ±0.34°C. In spite of apparent temporary insulation 

 failure, most of the profiles finally classified as catastrophic failures and partial successes 

 appeared to record valid temperatures at depths greater than the first indication of 

 insulation failure. 



"This type of insulation failure, an abrupt increase in temperature over a small depth interval followed by 

 an apparent "healing" of the insulation failure and a return to recording what appears to be a correct 

 temperature, was first identified during the analysis of the 1830-m profiles. A visual re-examination of the 

 460-m set I profiles showed that this type of insulation failure also occurred when the 460-m probes were 

 used. The re-examination showed indications of this type of failure in 6.9% (101 out of 1458) of the 

 460-m set I profiles. In comparison, 15 out of 18 RAPLOC/DEEPTOW 1830-m profiles and one out of 

 eight CAPER profiles showed this type of insulation failure, which suggests that this type of failure is 

 more likely to occur when 1830-m probes are used than when 460-m probes are used. 



102 



