TEMPERATURE STRUCTURE VARIABILITY 



In addition to the general classification of sea temperature 

 structure by degree of roughness, a statistical analysis was con- 

 ducted to determine isotherm depth variation and thus identify 

 oceanic regions by their statistical differences. The analysis 

 included isotherm steepness, which can be considered a measure 

 of roughness. 



Each section of the continuous towing track was alphabeti- 

 cally identified by 27 sections (A to Z, AA) (fig. 15), and the time 

 and geographical position recorded (table 2). The selection of 

 sample sections for analysis was made to obtain geographical 

 coverage of an area during a period when the tow was continuous 

 in one direction. The length and quality of the sample towing were 

 planned to be adequate for reliability in statistical results. For 

 geographical considerations, the midpoint of the sections is treated 

 as a unit or data point. 



Prior investigations studied the variability of surface and 

 subsurface sea temperatures; others developed procedures for 

 the statistical analysis of physical properties applicable to tem- 

 perature variability. 15, 16 - 17 - 18, 19, 20 In this report, three 

 methods of studying isotherm depth variability are employed: (1) 

 differences in depth values — isotherm slopes; (2) autocorrelation 

 of depth values; and (3) power spectrum of depth values. 



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