FISHERY BULLETIN: VOL. 69, NO. 2 



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Figure 8. — Sea-surface temperature anomaly for August 

 1955. Hatched areas colder than normal. Heavy lines 

 represent the 1° C anomaly contours which define warm 

 ( + ) or cold ( — ) cells. 



•J 



Figure 10. — Sea-surface temperature anomaly for Feb- 

 ruary 1956. Hatched areas colder than normal. Heavy 

 lines represent the 1° C anomaly contours which define 

 warm ( -|- ) or cold ( — ) cells. 



Figure 9. — Sea-surface temperature anomaly for No- 

 vember 1955. Hatched areas colder than normal. Heavy 

 lines represent the 1° C anomaly contours which define 

 warm ( -|- ) or cold ( — ) cells. 



Figure 11. — Sea-surface temperature anomaly for Au- 

 gust 1956. Hatched areas colder than normal. Heavy 

 lines represent the 1° C anomaly contours which define 

 warm (-f ) or cold ( — ) cells. 



warm cell at lat 36° N to 50° N, long 175° W to 

 150° E was the only prominent feature in evi- 

 dence and remained so until August 1956, when 

 a large cold cell developed just east of it (Figure 

 11). This latter feature was short-lived, how- 

 ever, and during the next few months the posi- 

 tive area once again expanded eastward while 

 the tendency of anomalies along the North Amer- 

 ican coast changed from variable to predomi- 

 nantly negative. The chart for November 1956 

 (Figure 12) depicts the result of this process. 

 Transition to a second phase in the long-term 

 evolution of the anomaly (ield was foreshadowed 

 l)y a small cold cell at lat 25° N to 30° N, long 



160° E to 170° E (Figure 12). This cold cell 

 grew in size but remained in about the same 

 location through March 1957 (Figure 13) while 

 the area of positive anomalies edged toward the 

 North American coast. The transition was 

 complete by June, when the cold cell shifted 

 north and stretched eastward in a belt of neg- 

 ative anomalies between lat 30° N and 40° N 

 (Figure 11). Positive values prevailed in the 

 Gulf of Alaska and along the North American 

 coast, effecting an almost complete reversal 

 from the late 1955 iiattern. 



The negative anomalies in the west central 

 sector, long 175° W to 160° E, contracted to form 



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