PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 565 
showing a warning of about 4° at the surface (7.22° to 8.33° in May, according to 
the locality), but with very little change at 100 meters. 
Turning now to the opposite side of the gulf, Mavor’s (1923) tables show the cen- 
tral part of the Bay of Fundy warming only fractionally at any level from April 9 
to May 4, 1917 (whole column then between 1.9° and 2.8°), but then more rapidly 
to 8.18° at the surface, 4.68° at 30 meters, and 3.92° at 100 meters on June 15. 
Assuming, from the character of the winters preceding, that the mean temperature 
at 40 meters ranged about l p lower at the beginning of spring in 1920 than in 1915, 
the difference between the April and May readings, just summarized, suggests that 
Temperature, Centigrade 
]° 2 ° 3 ° 4 ° 5 ° 6 ° 7 ° 8 ° 
Fig. 33. — Vertical distribution of temperature in Ipswich Bay on April 9, 1920 (A, station 
20092), and on May 7 and 8, 1920 (.B, station 20122) 
this level normally warms by about 1° during the interval from mid- April to'mid-May 
in the parts of the gulf where the change is most rapid. 
Taking the open gulf as a whole, the 100-meter readings for April, 1920 (a^cold 
year), so closely reproduced the May readings for 1915 (a warm year) 18 that the tem- 
perature of the mid-depths may be described as virtually stationary during this part 
of the spring. 
As the result of the two contrasting processes— vernal warming in the western side 
of the gulf and the inflow of cold water into the eastern — the regional distribution 
18 Maximum divergence at this level, for pairs of stations, was only from 3° in the western basin on Apr. 18, 1920, station 
20115, to 4.8° on May 4, 1915 .station 10267. 
