Figure 3. — Continued. 



Table 1. — Percentages of temperature class intervals (TCI's) in 

 the northern Middle Atlantic Bight during spring 1968-76. 



Table 3. — Percentages of temperature class intervals (TCI's) in 

 the southern Middle Atlantic Bight during spring 1968-76. 











TCI 









Observed 

 index 











TCI 









Observed 





0°- 



2°- 



4°- 



6°- 



8°- 



10°- 



12°- 



2°- 



4°- 



6°- 



8°- 



10°- 



12°- 



14°- 



index 



Year 



2°C 



4°C 



6°C 



8°C 



10°C 



12°C 



14°C 



(°C) 



Year 



4°C 



6°C 



8°C 



10°C 



12°C 



14°C 



16°C 



(°C) 



1968 



3 



43 



16 



12 



8 



18 







5.7 



1968 



21 



30 



24 



20 



5 











6.2 



1969 







36 



21 



14 



15 



14 







6.0 



1969 



27 



37 



12 



10 



14 











5.9 



1970 







5 



68 



7 



11 



8 



2 



6.2 



1970 







24 



52 



11 



8 



5 







7.4 



1971 







39 



21 



4 



10 



14 



2 



5.9 



1971 



2 



38 



31 



21 



5 



1 



1 



6.9 



1972 







12 



37 



21 



10 



12 



8 



6.9 



1972 







14 



25 



35 



23 



3 







8.5 



1973 







11 



34 



16 



11 



15 



12 



7.3 



1973 







17 



45 



21 



15 



2 







7.8 



1974 











19 



43 



11 



19 



8 



8.1 



1974 







3 



21 



23 



36 



17 







9.9 



1975 







4 



29 



30 



15 



22 







7.4 



1975 







24 



25 



29 



16 



6 







8.1 



1976 







2 



26 



20 



21 



24 



7 



8.2 



1976 







8 



33 



25 



29 



5 







8.8 



Mean 



<1 



17 



30 



20 



12 



16 



4 



6.9 



Mean 



6 



22 



30 



22 



17 



4 



<1 



7.7 



Table 2. — Percentages of temperature class intervals (TCI's) in 

 the northern Middle Atlantic Bight during autumn 1964-76. 









TCI 







Observed 





6°- 



8°- 



10°- 



12°- 



14°- 



16°- 



index 



Year 



8°C 



10°C 



12°C 



14°C 



16°C 



18°C 



(°C) 



1964 



1 



40 



44 



12 



3 







10.5 



1965 







33 



53 



14 











10.6 



1966 







1 



67 



32 











11.6 



1967 



12 



45 



39 



4 











9.7 



1968 







34 



30 



25 



11 







11.3 



1969 







7 



45 



32 



16 







12.1 



1970 



2 



27 



44 



26 



1 







10.9 



1971 



11 



11 



38 



32 



8 







11.3 



1972 







7 



28 



44 



21 







12.6 



1973 



1 



4 



33 



47 



15 







12.4 



1974 







5 



36 



44 



15 







12.4 



1975 



1 



2 



57 



34 



3 



2 



11.7 



1976 







10 



32 



35 



23 



1 



12.6 



Mean 



2 



17 



42 



29 



9 



<1 



11.5 



other extreme, water <4°C averaged about 17% of the 

 area but its high variability (0-46%) probably influences 

 mean conditions as much as the more steady (10-31%) 

 encroachment of slope water onto the continental shelf. 

 The highest annual percentages of water >10°C (1976) 

 and >4°C (1968) resulted in the warmest and coldest in- 

 dices, respectively. 



Autumn 1964-76. — Bottom temperatures during the 

 autumn in the Northern Bight fluctuated quite 

 dramatically between years since 1964 (Fig. 6, Table 6). 

 Except for a decline in 1975, a warming trend is indi- 

 cated with maximum adjusted temperatures of 12.6°- 

 12.8°C occurring since 1972. Most dramatic changes in the 

 adjusted indices are the decrease from 12.5°C in 1966 to a 

 minimum of 9.7 C C in 1967 followed by an increase to 

 11.2°C in 1968. Adjusted and observed temperatures 

 exhibited nearly the same annual variations which 

 resulted in nearly identical 13-yr means of 11.6°C and 

 11.7°C, respectively. The autumn anomalies are shown 

 in Figure 5 and Table 7. 



In most cases, years of the same or closely similar 

 observed temperatures had similar TCI percentages 

 (Table 2). The coldest year (1967) had no water >14°C 

 and all years (1969, 1972, 1973, 1974, 1976) that had in- 

 dices >12°C had only 1% or less of water <8°C and only 

 10% or less of water <10°C. The 10°-12°C TCI usually 

 dominated in all years and averaged 42% of the total bot- 

 tom area during the time series. 



Southern Middle Atlantic Bight 



Spring 1968-76. — Adjusted bottom-water tempera- 

 tures in the spring in the Southern Bight are character- 

 ized by large annual variations and a general warming 



