or impede icebergs as they drift along the eastern 

 slopes of the Grand Banks. Gradient 4 is a meas- 

 ure of the strength of generally westerly winds 

 along the north slopes of the Grand Banks. These 

 winds are often important in carrying icebergs 

 away from the northeast Newfoundland coast and 

 out into the Labrador Current. However, if they 

 are too strong when icebergs reach the northeast 

 corner of the Grand Banks where the Labrador 

 Current turns south, then the icebergs may be 

 carried eastward out of Labrador Current and 



into warmer waters which drift generally north- 

 eastward. 



Gradients 1 and 2 (see figure 20) indicate 

 winds more unfavorable for the southward drift 

 of ice than normal in March and early April, and 

 more favorable than normal in later April, May, 

 and June. This appears to have had the effect of 

 initially limiting the supply of icebergs to the 

 northern Grand Banks. The fact that there were 

 only two icebergs south of 48N in May be attrib- 

 uted to the time required for icebergs to drift 



PRESSURE GRADIENT 



PRESSURE GRADIENT 



mbs 

 10 



mbs 

 10 



mbs 

 10 



PRESSURE GRADIENT 2 



PRESSURE GRADIENT 4 



F M 



15 I 15 



Figure 20.— Pressure Gradients 1-4. 



25 



