

Profile 





Temperature, °C 





Average 



Standard 



Difference 



Number 



Number 



Difference 



Deviation 



Random 



XBT 1-45 



35 



0.04 



0.21 



Most negative 



XBT 46-80 



29 



-0.72 



0.90 



All positive 



XBT 8 1-96 



14 



1.14 



0.50 



All negative 



XBT 97-177 



60 



-1.03 



0.52 



Table 22. Statistical summary of CAPER's MOANA WAVE surface 

 temperature differences. 



figure 23 and summarized in table 23. For the first 45 profiles, the 400-m temperatures 

 varied randomly about 6.42°C, with a standard deviation of 0.2 1°C. For the rest of the 

 profiles, the 400-m temperatures exhibited a behavior similar to that observed at the surface, 

 except that the 400-m variations were not the same as the surface variation. Thus the 

 surface temperature differences are not the result of a simple shift in the temperature scale. 



Also shown in figure 23 are the CTD/SV 400-m temperatures. The average 400-m 

 temperature for 22 measurements was 6.23°C, with a standard deviation of 0.1 9°C. These 

 measurements do not exhibit an erratic behavior such as that exhibited by the 400-m 

 XBT measurements. Note that among the first 45 profiles, there is a group of three that 

 measures temperature about 7.0°C and is about 0.5°C higher than the remainder of the 

 400-m measurements. CTD/SV 6 confirms these "anomalous" measurements as correct 

 measurements. 



Note also that all the MOANA WAVE XBT temperatures included in figure 23 were 

 obtained from visually acceptable XBT profiles; that is, there was no basis after a visual 

 inspection to reject the profiles as being incorrect. Figure 24 illustrates this point. For 

 comparison, three XBT profiles are superimposed on a common chart: XBT 18, 56 and 82. 

 (These profiles are from figure 23.) In the absence of any other information, such as a 

 bucket temperature, all these profiles would be accepted as correct. In other words, there is 

 no valid reason for rejecting any one of or all three profiles as erroneous. The XBT 18 

 surface temperature agreed within 0.1 9°C of the bucket temperature, and the 400-m 

 temperature agreed within 0.1 7°C of the average CTD/SV 400-m temperature. The XBT 56 

 surface temperature was 2.84°C less than the bucket temperature, and the XBT 82 surface 

 temperature was 2.22° greater. At 400 m, the differences from the average CTD/SV 400-m 

 temperatures were -1.1 0°C and 2.66°C, respectively. 



Shown in figure 25 are a pair of interesting MOANA WAVE XBT profiles: XBT 96 

 and XBT 98. These were taken 1 h 50 min apart in time and 5.5 nmi from each other. At 

 the same time XBT 96 was made CTD/SV 19 was made, and at the same time XBT 98 was 

 made CTD/SV 20 was made. Table 24 compares the surface and 400-m temperatures 

 measured by XBT 96 and XBT 98 with CTD/SV 19 and CTD/SV 20. The CTD/SV 

 measurements indicate a real change in the surface and 400-m temperatures. However, the 

 change was much less than the change indicated by the XBT measurements. Again, in the 

 absence of any other information both XBT profiles would be accepted as correct. However, 

 as indicated by the CTD/SV measurements, neither is correct. 



55 



