intensification of the North Atlantic Drift in the 

 vicinity of Ocean Station DELTA during this 

 period. Another dominant trend in the vertical 

 temperature structure was the increase in tempera- 

 ture of the water between 400 and 800 meters dur- 

 ing the period from July 1966 to July 11)67. Tlie 

 water in this depth interval was about 1.0° C. 

 warmer in July 1967 than in July 1966. 



Vertical salinity distribution: 



The dominant feature of the salinity structure 

 was the maximum value between 100 and 150 

 meters. The exact location of maxima and minima 

 is smoothed out in the averaging process, but it is 

 evident from figure 22 that there was a maximum 

 salinity value at about 100 meters in July 1966 and 

 that as winter approached, convective mixing low- 

 ered the maximum salinity and caused it to be 

 located deeper in the water column. However, tJie 

 structure during the October-November and No- 

 vember-December periods is anomalous, as was 

 observed in the temperature structure. The salinity 

 structure during the October-November period re- 

 vealed a greater maximum salinity value than any 

 other period (36.1-±%o) and suggests again an in- 

 flux of North Atlantic Drift, water. The salinity 

 values between 100 and 800 meters were sig- 

 nificantly greater during this period than during 

 the previous summer period. 



From January 1967 to July 1967 the vertical 

 salinity structure changed from a near isohaline 

 distribution (35.60-35.75%o) in January in the 

 upper 300 metei-s to the establishment of a salinity 

 maximum (36.10%o) at about 50 metere. In addi- 

 tion, there was a large increase in the salinity 



values between 400 and 800 meters during this 

 period. Tlie increase amounted to nearly 0.20%o. 



SUMMARY 



The results of eight oceanogi-aphic patrols on 

 Ocean Station DELTA between July 1966 and 

 July 1967 confirmed the earlier reports of complex 

 oceanographic conditions in this area. It was 

 found that the best way to describe the oceano- 

 graphic conditions for a given period of time was 

 in terms of deviations from a mean value. 



The analysis of the data revealed that the 

 normal seasonal cycle of heating in the summer 

 and cooling in the winter followed by convective 

 mixing and the formation of a d&ep mixed layer 

 was disturbed in the vicinity of Ocean Station 

 DELTA during the October-December 1966 pe- 

 riod. During this period there was an influx of 

 relatively wann, high salinity water below 100 

 meters probably associated with an extension of 

 the Gulf Stream system. It was observed that 

 Ocean Station DELTA is located in a frontal 

 zone between a subarctic water mass in the north 

 and a water mass probably of Gulf Stream origin 

 on the south. 



In addition to significant fluctuations in condi- 

 tions from month to month, there was considerable 

 difference in conditions over a year's period. From 

 July 1966 and July 1967 the water mass below 

 300 meters showed a considerable increase in both 

 temiDerature and salinity. This is probably due to 

 the close proximity of Ocean Station DELTA to 

 the edge of the North Atlantic Drift which under- 

 goes considerable fluctuations in location and 

 magnitude. 



Literature Cited 



Gorton E. L., 1067. Variation in the Vertical AVater Struc- 

 ture at OWS DELTA (44° N., 41° AV.), U.S. Xaval 

 Oceanograi)liic Ofliee, IR No. 67-68 (Informal). 



McGary, J. W. and R. JI. Morse, 1964. Oeeanograpliic 



Observations at Nortli Atlantic Ocean Station DELTA, 

 March-April 1()63, U.S. Coa.st Guard Oceanographic 

 Reix)rt No. 3, CG-373-3. 



