AMELIORATIONS OF PRESENT ARCTIC CLIMATES 405 



and upper Atlantic layers in their normal circulatory courses. Only 

 the upper layer (the Greater Gulf Stream) and the upper part of the 

 middle Atlantic layer are permitted to flow directly on over the 

 obliquely set weir. The lower part of the thick middle layer is 

 shunted to the northwest by the oblique attitude of the weir. 



A natural effect of this oblique divergence by an intercontinental 

 dam whose side is much buttressed by submerged ridges is more or 

 less of tortuous and rotational subcurrents, some of which should 

 appear at the surface in more or less modified forms. This effect 

 should be cumulative toward the west side of the weir or the north- 

 west corner of the Atlantic, in other words, the angle between the 

 oblique weir and the east coast of North America. Indications of 

 this shunting and the incidental deformation of currents and dis- 

 tributions is shown on the accompanying saKnity map (Fig. 2), 

 especially to the south and the southwest and west sides of Iceland 

 and off the mouth of the Baffin Bay inlet. The climatic conditions 

 of Iceland are in themselves very suggestive, for Iceland is far toward 

 the western end of the weir and on the west side of the Atlantic. 

 It is, moreover, at that end of the weir over which the cold polar 

 waters pour in going southward. On the same salinity chart, but 

 farther from the axis of the ridge -dam and obviously controlled by 

 the south-projecting point of Greenland, is a notable loop of the 

 salinity curves toward the mouth of Baffin Bay. These, to be sure, 

 are surface features, but they probably represent and depend upon 

 a deeper movement. They definitely suggest the divergence of an 

 undercurrent such as that which gives rise to the striking ameliora- 

 tions of climate in Baffin Bay. Such an undercurrent shunted into 

 the Baffin Bay trough offers a very natural explanation of the singu- 

 lar way in which the East Greenland polar current of lighter ice- 

 laden water curves so sharply about the southern point of Green- 

 land and is carried northward in crossing the mouth of the Baffin 

 Bay trough, because the latter floats on the former and is carried 

 in due degree along its course. 



With such intimate relations to much colder and less saline 

 waters, the Atlantic offshoot into Baffin Bay becomes reduced in 

 temperature and in saHnity in its 1,500 mile advance to the head of 

 the bay, but still it gives striking evidence of being more effective 



