enough frequency, annual fluctuations of 

 the 3 * C and 4" C isotherms were not suf- 

 ficiently well defined. However, that data 

 which were collected seems to agree with 

 the fluctuations of the warmer levels. 



ISOHALINES 



The isohalines showed a similar seasonal 

 variation of depth, figure 6. The salinity 

 appeared to generally decrease with depth. 

 The lowest surface salinity present was 

 about 36.3 /»». The saUnity down to 

 about 100 meters (about 35.1 * /oo ) 

 generally followed the fluctuations of the 

 36.3 o/^o isohahne. The 35.0 "/ooisoha- 

 line also followed the general trend of the 

 shallower isohahnes, but less closely than 

 the others. 



Montlily variations of the 36.3 "/oo 

 to 35.1 "/oo isohalines were similar except 

 for several occasions where there appeared 

 to be a lag between the shallower and 

 deeper isohaUnes. 



Between June 1967 and July 1967 the 

 isohalines became shallower and then 

 descended 280 meters or more by Sep- 

 tember. The levels rose to within about 40 

 meters of tlie July level by February 1968. 

 These lower winter values were followed 

 by the depth of isohalines increasing for 

 the next one to three months (depending 

 on the isohaline), followed by isohalines 

 moving to their shallowest level in June, 

 for the liigher values of salinity, and July 

 for less saline water. By August, all layers 

 had descended, but September showed the 

 isohalines to be rather irregular, with some 

 moving shallower, and others deeper. 

 From October to November, the isohalines 

 had become shallower, followed by a gen- 

 eral sinking through February 1969. 



Various layers moved differently until 

 April when all layers were shallower than 

 February. During the next two to three 

 months, the layers moved deeper, fol- 

 lowed by a general overall rise until Jan- 

 uary 1970. Levels moved deeper until 

 March, after which they rose to a June 

 peak. Levels descended until September. 

 A sharp rise was apparent for October, 

 then November showed layers had moved 

 deeper. 



The following year was similar to 1970 

 with layers shallow in January, descending 

 through April, a yearly high in July, 

 descending to September, a short rise to 

 November, followed by descending levels 

 which continued to January 1972, after 

 which levels rose through March. 



From June 1972 until March 1973 levels 

 did not generally appear to vary by more 

 than 50 meters between any two months. 



STANDARD DEVIATION 



Since all data for a month was averaged, 

 the standard deviation for both tempeature 

 and a salinity for each month was com- 

 puted at 100 meter intervals. 



Normally, one would expect the greatest 

 deviation to occur at the surface or in the 

 near surface layer where the atmospheric 

 effects would be greatest. Furthermore, 

 an open ocean area, such as Ocean Station 

 ECHO, should have a greater deviation in 

 tliis surface region for temperature, than 

 for salinity, since runoff would not have an 

 effect. 



As expected, temperature did show a 

 much greater deviation tlian salinity for vir- 

 tually all months and depths. However, the 

 greatest deviation did not only occur at the 

 surface, but in deeper layers, figure 7. 



