696 
BULLETIN OP THE BUREAU OF FISHERIES 
Mean winter temperatures °F, with departures from normal (/. W. Smith , 1913-1921 ) — Continued 
1915-16 
Boston 
34.2 
+2.6 
33.0 
+6.0 
25.5 
-2.5 
30.6 
-4.4 
Portland 
29.4 
+2.3 
26.6 
+4.6 
20.6 
-3.2 
26.8 
-3.2 
Eastport 
29.6 
+4.3 
22. 6 
+2.5 
19.3 
-2. 1 
24.6 
-4.3 
1919-20 
Boston 
28.8 
-2.8 
21.0 
-0.6 
27.6 
-0.4 
39.2 
+4.2 
Portland 
22.8 
-4.3 
14.6 
-7.4 
22.2 
-1.6 
34.6 
+2.6 
Eastport 
20.0 
-5.3 
11.5 
-8.6 
21. 1 
—0.3 
30.4 
+ 1.5 
1920-21 
Boston 
35.6 
27.8 
27.5 
+4.0 
+0.7 
+2.2 
Portland 
Eastport . 
The diagrams of air and surface temperature at Gloucester and at Boothbay for 
the winter of 1919-20 (figs. 29 and 30) show the temperature of the water closely 
following that of the air in its 10-day fluctuations, and reflecting a loss of heat by 
radiation more or less rapid as the difference between the temperature of air and 
water is greater or less. 75 
The loss of heat from the surface of the gulf increases proportionately from 
November on, as the average difference between air and water increases, a general 
rule illustrated by the temperature cycle of Massachusetts Bay for the winter of 
1924-25 (p. 651) . The water continues to suffer a net loss of heat in this way until the 
average temperature of the air once more rises above that of the water, an event to 
be expected about the tenth of March (p. 668). 
CHILLING EFFECT OF MELTING SNOW 
Another cooling agent becomes effective from December until spring — namely? 
the melting of the snow that falls on the surface of the gulf. The amount of heat 
taken from the water by melting snow is, of course, that required to melt an equiv- 
alent amount of ice; a fall of 1 foot of snow (a moderate snowstorm for northern 
New England and the Maritime Provinces) would represent approximately 1-1 24 
inches of ice, more or less according to the quality of the snow. 
The normal snowfall, by months, for the lands bounding the gulf is tabulated 
below from data supplied by the United States Weather Bureau; also the actual 
snowfall for representative winters since the oceanographic investigation of the gulf 
was undertaken. 
Normal snowfall and its equivalent in ivater, both given in inches 
Locality 
November 
December 
January 
February 
March 
April 
Snow 
Equiv- 
alent 
water 
Snow 
Equiv- 
alent 
water 
Snow 
Equiv- 
alent 
water 
Snow 
Equiv- 
alent 
water 
Snow 
Equiv- 
alent 
water 
Snow 
Equiv- 
alent 
water 
Boston 
0.6 
0.08 
5.8 
0.55 
9.7 
0.87 
13.7 
1. 23 
9.0 
0. 87 
3.7 
0.46 
Portland 
3.6 
.64 
10.8 
1. 70 
16.0 
2. 32 
20.0 
3. 02 
11.7 
1.82 
4.2 
.78 
Eastport 
3.4 
.40 
11.7 
1. 26 
17.6 
1. 72 
19.7 
1.90 
13.3 
1. 28 
10.1 
1. 04 
Yarmouth, Nova Scotia 
4.0 
.40 
14.4 
1. 47 
20.3 
2.03 
21.8 
2. 18 
13.3 
1. 30 
5.5 
.50 
75 The air temperature of the coldest days was many degrees below the 10-day averages shown on the diagrams, often 10° 
colder than the surface of the water. 
