Discussion 



The five patrols at ocean station ECHO from 

 21 September 1966 to 13 October 1967 cover 

 over a one-year period. Although there are 

 many gaps in the data, it is felt that there are 

 enough data for a preliminary study of ocean- 

 ographic conditions at ocean station ECHO 

 which can be used as a basis for future reports. 



Figures 8-12 shovi^ the vertical envelopes of 

 temperature vs. depth for each of the five 

 patrols. Figure 8 shows the vertical tempera- 

 ture envelope for ocean station ECHO between 

 21 September and 13 October 1966. During this 

 time, the surface temperature ranged between 

 23.74 and 25.39° C. The water column was 

 isothermal in the upper 25 meters, after which 

 the seasonal thermocline was evident down to 

 125 meters with a gradient of about 6.57° 

 C./lOO meters. Below this there was a gradual 

 gradient down to a depth of about 1200 meters. 



By February the surface temperature had 

 dropped to a range of 18.14-19.16° C, as shown 

 in Figure 9. The water column was nearly 

 isothermal at the majority of the stations to a 

 depth of 100-150 meters. The thermocline then 

 extended down to about 1100 meters. 



Seasonal warming was evident at the surface 

 during the patrol of the USCGC ANDROSCOG- 

 GIN in June 1967 (See Figure 10). The surface 

 temperature had increased to 19.92-21.53° C. 

 Between 100 and 300 meters the temperature 

 structure was essentially the same as the pre- 

 vious patrol (February). Below 300 meters 

 there were some erratic changes. Stations No. 

 1 and No. 2, located in the SE. portion of the 

 ten-mile grid, revealed exceptionally cold water 

 between the depths of 500 and 1300 meters. 

 Below 1300 meters the temperature returned 

 to normal. Station No. 11, taken 20 days later 

 in the NW. portion of the grid had water tem- 

 peratures higher than the apparent normal 

 between the same depths. The greatest tem- 

 perature difi'erence between station No. 2 and 

 No. 11 was 6.1° C. which occurred at the 800 

 meter level. There was a 5.7° C. difference at 

 the 700 meter level. 



The maximum surface temperature appears 

 to occur in August (24.38-27.08° C.) . Figure 11 

 shows a large temperature gradient in the 

 upper 100 meters of the water column. Al- 

 though the surface temperature had increased, 

 below the 75 meter level the water temperature 

 was substantially colder than during the pre- 

 vious patrol. 



Seasonal cooling began in September. The 

 surface temperatures ranged fi'om 24.47 to 

 25.50° C. As seen in Figure 12, below 50 meters 

 the water temperature was higher than any 

 other time it was observed during the year, 

 though it gradually decreased with time. 



The vertical salinity envelopes are shown in 

 Figures 13-17. During the patrol of the USCGC 

 YAKUTAT the surface salinities ranged be- 

 tween 35.91 and 36.43%„. There was a slight 

 increase in salinity with depth with the max- 

 imum salinity occurring between 50 and 100 

 meters. As shown in Figure 13, below this 

 there was a negative gradient extending down 

 to 1000 meters. 



By February 1967, the surface salinities had 

 increased to 36.43-36. 59%o and the water 

 column was isohaline to a depth of about 200- 

 240 meters. A marked salinity gradient existed 

 between about 200 and 900 meters as shown 

 in Figure 14. 



The surface salinities during June (Figure 

 15) were slightly lower than the previous 

 patrol in February and ranged between 36.28 

 and 36.48%o. Again, as with the temperature 

 data, the salinity values for the USCGC AN- 

 DROSCOGGIN stations No. 1 and No. 2 were 

 considerably lower between the depths of 500 

 and 1000 meters, and were higher at station 

 No. 11. The greatest salinity diff'erence between 

 stations No. 2 and No. 11 was 0.79%o which 

 occurred at the 800 meter level. Another sig- 

 nificant difference was 0.74%o at the 700 meter 

 level. 



During the patrol of the USCGC ABSECON 

 from 17 July to 6 August 1967 the surface 

 salinities had increased to 36.53-36.68%o. From 



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