Based on Yoshida's work, the computed velocity 

 of iipwelling at standard section A3 was 0.016 

 cm/s. The velocity' of the observed upwelling 

 from the displacement of the 27.0 and 27.5 

 isopycnals was 0.017 cm/s. 



The upwelling along the western boundary at 

 A3 resulted in an increase in the density of the 

 upper 300 meters and an 8 dynamic centimeter 

 decrease in dynamic height at the surface be- 

 tween the first two occupations. Further to the 

 east, in the trough region, there was a slight 

 decrease in density which resulted in a 1 dynamic 

 centimeter increase in surface dynamic height. 

 The change in the density structure of the upper 

 1000 meters at A3 was responsible for the sharp 

 decrease in volume transport noted between 20 



and 24 May. The increased transport between 

 the second and third occupations resulted from 

 a decrease in density at the western end of A3 

 and an inci'ease in density at the trough stations. 

 While the results were not conclusive, the ob- 

 servations during 1971 strongly suggest that 

 localized winds on the Grand Banks may pro- 

 duce upwelling and downwelling which can 

 modify the mass distribution of the area and 

 can produce large localized variations in the 

 southward transport of the Labrador Current. 

 The time required for changes of this type to 

 occur is on the order of three to four days or 

 less. It is likely that this is only one of several 

 processes which is responsible for intensification 

 of the Labrador Current. 



