47 



the same, section for section. Tliat this is not the case is indicated by 

 figure 30 which shows that although the Labrador Current, in the 

 upper levels, was normal or even slightly denser than usual, the mixed 

 water was lighter than usual. As the mixed water is formed by the 

 mixing of water from the Labrador Current and the Atlantic Current it 

 follows that the Atlantic Current must have had lighter than usual 

 water, level for level. The Labrador Current and the mixed water 

 were completely crossed at all sections. 



26.9 27.0 



1000 



riGURF. 30.— Vertical distribution of density ((r,) in the Labrador Current, Atlantic Current and mixed 

 water in the Grand Banks region. Solid lines show conditions during the 1940 season and brolcen lines 

 represent the "-year mean for the period 1934-40. 



Figure 30 also demonstrates the degree to which the mixed water, 

 •characterized by low dynamic heights, is denser than either of its two 

 components, the Labrador Current and the Atlantic Current. It also 

 shows graphically that the reference surface of 1,000 decibars, which is 

 used for the construction of current maps for use by the patrol cutters, 

 is sufficiently deep for all but those regions covered by the Atlantic 

 Current; and that in those regions the maps show only slightly slower 

 velocities than actually exist there, if one may go so far in drawing 

 conclusions from the degree of discrepancy in the values of at at a 

 depth of 1,000 meters m figure 30. 



