Table 12.— Low salinity (<34.S7..) coastal water encountered by 

 SOOP vessels in the Middle Atlantic Bight in 1975. 



74" 



'A = anticyclonic. 



70°'22'W). The surface expression of this eddy showed as 

 a peak in the sea surface salinity and a steep increase in 

 the sea surface temperature. 



This eddy was discussed in detail in the June issue of 

 (lulfstream and comparisons made between this XBT 

 transect, the Gulfstream, and with the Experimental 

 Ocean Frontal Analysis Chart (18 June 1975) showed 

 quite good agreement in both position and areal extent. 



Eddy crossings two through five (App. Figs. 60 through 

 62 and 64) were all the same anticyclonic eddy. Two of 

 the crossings (App. P^igs. 60 and 61) were on the edge of 

 the eddy and two of the crossings (App. Figs. 62 and 64) 

 were closer to the center. From the two crossings that 

 were near the center of the eddy, an estimate of the 

 translational speed of the eddy was possible. The Export 

 Defender (App. Fig. 62) crossed the eddy on 18 October 

 and was centered along this transect between stations 7 

 and 8 (lat. 38°57'N, long. 7r03'W). The Mormac Argo 

 (App. Fig. 64) crossed the eddy on 22 October and was 

 centered between stations 33 and 34 (lat. 38°36'N, long. 

 71°2rW). The distance between the two estimated 

 center points was 25 n.mi. and the time difference was 

 109 h (Fig. 2). The calculated translational speed was 5.5 

 n.mi. /day (10.2 km/day) which is somewhat higher than 



40'' - 



38° 



72° 

 J_ 



70° 



OCT 22 



40'' 



- 38° 



74° 



72° 



70° 



Figure 2. — Distance between the estimated center points of an anti- 

 cyclonic eddy crossed in October 1975. 



other translational speed measurements of the same 

 eddy (Bisagni 1976). 



Gulf of Maine Transects 



Beginning in June, we began making monthly XBT 

 transects across the Gulf of Maine utilizing the Canadian 

 National Railway Ferry MV Bluenose. These transects, 

 in conjunction with other opportunistic Coast Guard 

 transects, are employed in the monitoring of the seasonal 

 variations of temperature in the Gulf of Maine. This 

 program is expected to continue into 1976 and 1977 to 

 determine if the Gulf of Maine continues its warming 

 trend (Chamberlin et al. 1978). 



Brief smalyses of these monthly transects were dis- 

 tributed to fishermen and scientists in both the United 

 States and Canada, and copies are available from the 

 Northeast Fisheries Center at Woods Hole, Mass. A more 

 detailed analysis of these transects exists in Chamberlin 

 et al. (1978). 



Features and conditions looked for in the Gulf of 

 Maine were slope water and Scotian shelf water influence 

 and general circulation. Slope water is usually identified 

 by the 9''C isotherm at 200-m depth (Worthington 1964). 

 The warmer water that exists in the deeper basins of the 

 Gulf of Maine, especially in the winter months, could be 

 attributed to intrusions of slope water through the north- 

 east channel. 



Although some transects showed 9°C or warmer water 

 at depth (App. Figs. 76, 79 through 82), without sup- 

 porting subsurface salinity data, verification that this is 

 due to intrusion of slope water into the Gulf of Maine is 

 impossible. 



One transect (App. Fig. 76) in particular was rather 

 striking. In July the USCGC Evergreen transected 11°C 

 water at depth, north of Georges Bank. This 11°C water 

 was closely associated with the northeast channel and 



10 



