100 and 1200 meters, gradually increasing with 

 time. 



During September and October 1967 the 

 salinities below 50 meters were higher than 

 during the previous month and gradually de- 

 creased with time. 



Figures 20 through 24 are the T-S diagrams 

 for the five patrols at ocean station ECHO 

 from 21 September 1966 to 13 October 1967. 

 With a few noted exceptions, the T-S plots 

 fell within or, in a few cases, just outside the 

 limits for North Atlantic Central Water 

 (Sverdrup et al. 1942, p. 669). 



During the patrol of the USCGC YAKUTAT 

 one point at the 1000 meter level was well 

 outside the limits of the envelope (Figure 20). 

 These values of temperature and salinity were 

 gathered on 12 October 1966, and the validity 

 of this point is doubtful as has been mentioned 

 before. 



Figure 21 shows the T-S plot for the Febru- 

 ary 1967 cruise of the USCGC MCCULLOCH. 

 Particularly noteworthy is the mixed layer ex- 

 tending down to about 200 meters. 



The T-S diagram for the patrol of the 

 USCGC ANDROSCOGGIN in June 1967 (Fig- 

 ure 22) shows the exceptionally cold and low 

 saline water encountered between 800 and 1200 

 meters on the 1st and 2nd of June 1967. These 

 points fall well outside of the envelope for the 

 North Atlantic Central Water. 



The T-S diagrams for the patrols of the 

 USCGC ABSECON during July and August 

 1967 and that of the USCGC MCCULLOCH 

 during September and October 1967 are shown 

 in Figures 23 and 24, respectively. The data 

 points of both patrols fall within the envelope 

 for North Atlantic Central Water and both 

 show the rise in temperature of the surface 

 layer. 



Summary 



The results of the five patrols at ocean sta- 

 tion ECHO from 21 September 1966 to 13 

 October 1967 indicates that the maximum sur- 

 face temperature occurred in late August and 

 the minimum occurred in February. The tem- 



perature gradient below the 200 meter level 

 remained basically the same throughout the 

 period observed with slightly lower tempera- 

 tures between the depths of 600 and 1100 

 meters during June due to colder water masses 

 apparently moving through the area. The water 

 column was very nearly isothermal in the up- 

 per 200 meters during Februai-y. After Feb- 

 ruary a temperature gradient developed reach- 

 ing a maximum about August. This gradient 

 then slowly started to decrease. 



The surface salinity also reached a maximum 

 in late August. The time of minimum surface 

 salinity is harder to determine with the avail- 

 able data, but indications are that it occurred 

 in January. Between the depths of 200 and 

 800 meters there was a high degree of cor- 

 relation between temperature and salinity 

 throughout the year. 



During September and October 1966 the 

 mixed layer extended down to about 30 meters. 

 By February 1967 it had increased in depth to 

 about 200 meters and all but disappeared dur- 

 ing the June 1967 patrol of the USCGC 

 ANDROSCOGGIN. 



The data for stations No. 1 and No. 2 during 

 the June 1967 patrol of the USCGC ANDROS- 

 COGGIN appear to be valid. At the 834 meter 

 level the temperature and salinity were a low 

 3.72° C. and 34.54%<„ respectively. In general, 

 there appeared to be lower temperature and 

 salinity values in the SE portion of the ten-mile 

 grid and higher values in the NW portion dur- 

 ing the June 1967 patrol. It is possible that 

 these low values were the result of meanders 

 passing through the area. 



LITERATURE CITED 



Morse, R.M., J.W. McGary, 1964. Oceanographic Ob- 

 servations At North Atlantic Ocean Station ECHO, 

 January-February 1963, U.S. Coast Guard Ocean- 

 ographic Data Report, CG 373-2 



LaFond, E.C., 1951. Processing Oceanographic Data, 

 U.S. Navy Hydrographic Office Pub. No. 614, 114 pp. 



Sverdrup, H.W., M.W. Johnson, and R.H. Fleming, 

 1942. The Oceans; Their Physics, Chemistry, and 

 General Biology, New York; Prentice Hall, 1087 p. 



