PHYSICAL OCEANOGRAPHY OF THE 6XJLF OF MAINE 



773 



the upper stratum than at greater depths, with most of our stations showing a 

 vertical range of 0.6 to 1 per mille between the surface and the 40 to 50 meter level 

 (.fig. 139). Eastward from Penobscot Bay we have found a more uniform gradient 

 of salinity from the surface downward, as illustrated by stations near Mount 

 Desert Island (fig. 107). 



Throughout the sector between Cape Cod and Mount Desert the difference in 

 salinity between the surface and the 40 to 50 meter level is everywhere considerable 

 in summer (though less than in spring, p. 728) — perhaps nowhere less than 0.3 per 



Salinity 



fi R -59 5 A R 



Meter 



20 



40 



60 



80 

 100 

 120 

 140 

 160 

 180 

 200 

 220 

 240 

 260 

 280 



300 



Fig. 13S. — Vertical distribution of salinity in the western side of the basin, in the offing of Cape 

 Ann, in July and August of different years. S, August 9, 1913 (station 10088); O, August 22, 

 1914 (station 10254); A, August 23, 1914 (station 10256); X, August 31, 1915 (station 10307). The 

 broken curve marks the approximate limits to annual variation 



mille in July or August, with a maximum vertical range of about 1 per mille in the 

 Massachusetts Bay region within these depth limits. 



Passing eastward from Mount Desert toward the Bay of Fundy, the vertical 

 range of salinity is progressively narrower and narrower, corresponding to the more 

 and more active tidal stirring. In the Grand Manan Channel so close an approach 

 to verticle homogeneity is maintained throughout the summer that the maximum 

 vertical range so far recorded for August has been only about 0.08 per mille, as 

 foUows: 



37755—27 18 



