Cape Bonavista-Grand Banks topography indicated that part of the transport 



The dynamic topography north and east of ^^ ^he Labrador Current along the southeastern 



Cape Bonavista indicates that the slope band ^lope of the Grand Banks passed over the 



of the Labrador Current was more intense northeastern corner of the Grand Banks and 



along the northeastern slope of the Grand "ot through the bathymetric trough between 



Banks during mid-April (fig. 3) than during the Grand Banks and Flemish Cap. 



mid-May (fig. 4). The mid-April survey also ^^^^ VARIATION OF THE 



substantiates the hypothesis (Smith et al LABRADOR CURRENT 

 1937) that part of the southward transport 



immediately east of Cape Bonavista spreads out Estimates of the degree of development of 

 over the Grand Banks or flows south along the the Labrador Current cannot be made solely 

 Avalon Peninsula. During the April survey on from the charts of the surface dynamic topog- 

 section Ala, two cores of water with tempera- raphy, so particular attention was paid to the 

 tures less than — 0.5°C were observed (fig. 13), time variation in the transport of the Labrador 

 but downstream on section Alb, only one core Current through section A3. Section A3 makes 

 was observed a day later (fig. 14). The chart a complete transect of the Labrador Current 

 of dynamic topography (fig. 3) suggests that from the dynamic trough east of the current to 

 the core of cold water on section Alb is related Grand Banks west of the current. Transports 

 to the more off'shore core observed on section were computed for the total flow of the Lab- 

 Ala. The water comprising the inshore cold rador Current, defined at section A3 as the total 

 core apparently either spread over the Gi'and southward flow west of the dynamic trough, 

 Banks or flowed down the east coast of the and for the cold core of the Labrador Current, 

 Avalon Peninsula. defined at section A3 as that part of the Lab- 

 During the comprehensive areal survey of rador Current possessing temperatures colder 

 16-27 May (fig. 4), the observed dynamic than 2°C and salinities less than 34.3°/^^ 



Table 1. Summary of volume transport of Labrador Current through Section A3 



Date Total Cold core 



of flow flow Ratio 



occupation (XIO 6 m 3/sec> (X106 mS/se-:) cold core flow/total flow 



10-12 April 1969 4.53 2.69 0.594 



21-22 May 1969 4.03 1.84 .457 



28-29 May 1969 5.50 3.91 .711 



1-2 June 1969 2.77 1.99 .719 



(table I). During the 12-day interval from 22 

 May to 2 June, the cold core transport doubled 

 and then decreased to its former value while 

 the total transport increased to its maximum 

 value and then decreased to its minimum ob- 

 served value during the Ice Patrol seacon. The 

 increase in total trpnsport from 21 to 22 May 

 to its maximum on 28-29 May was due to the 

 increase in the cold core transport as indicated 

 by the ratio of the cold core flow in the total 

 transport. The decrease in total transport from 

 its peak value to the minimum value on 1-2 

 June showed a lessening of the flow of the 

 Labrador Current but no change in the ratio of 

 cold core transport to total transport. 



Variation in the gradient of dynamic height 

 across the Labrador Current, due to changes at 



either or both ends of the transect, affects the 

 calculations of current velocity and volume 

 transport. Profiles of sea surface dynamic 

 height along section A3 (fig. 27) indicate that 

 the station possessing the lowest dynamic 

 height (trough station) was farther east during 

 the second occupation. The broadening of the 

 trough during this occupation was accompanied 

 by an anomalous banding (fig. 19) resulting in 

 computed transports of warm, saline (>6°C, 

 >34.6°/Qg) water southward along the western 

 side of the trough and relatively cold, fresh 

 (<2°C, <34.4°/^„) water northward along 

 the eastern side of the trough. 



The diff'erences in dynamic height at a given 

 depth between the trough station and the next 

 station immediately west were plotted versus 



