mixed water. In 1958 there were a number of such stations 

 showing atypical mixing, especially during the third survey. By 

 far the greatest number of these stations showed mixtures in- 

 termediate between typical mixed water and Atlantic Current 

 water. The curve for the 11-year mean for the Atlantic Current 

 water is not accurately representative since in most years the 

 surveys do not include sections which completely cross this cur- 

 rent. All of the surveys do result in a complete and representative 

 sampling of the Labrador Current and consequently fluctuations 

 found in this water mass are considered to be the best indicator 

 of changes taking place in the Ice Patrol area. 



Figure 24 shows lighter than average water present in 1958 at 

 each level and for each water mass. In the Atlantic Current water 

 above about 1,000 meters the effect of higher than average 

 salinities was outweighed by the higher temperatures. In the 

 mixed water the lower densities were largely the result of higher 

 temperatures in the upper 200 meters (with about average salini- 

 ties) while below 200 meters colder temperatures could not balance 

 the lower than average salinities. In the Labrador Current water 

 the salinities were below average at all levels and the temperatures 

 were above average except at the 150, 200 and 300-meters levels 

 where the temperatures were colder than average. 



Figure 25 shows the departures from average of the tempera- 

 tures and salinities in the Labrador Current water and their 

 approximate contributions to the departures from average density. 



Starting with the abnormal onshore wind system and consider- 

 ing that this moved surface and near surface water in to the 

 beach forcing a downward and seaward circulation along the 

 bottom at least to the depth of the shelf (ca 200 meters), this 

 would set up temporary instabilities the erasure of which, through 

 the resulting mixing, would tend to wipe out the temperature 

 minimum of the Labrador Current (50 to 100 meters) and lower 

 the temperature of the water at levels immediately beneath the 

 normal minimum. Such an hypothesis would explain the shape 

 of the curves in figure 25 down to about 300 meters, and except 

 for the small inversion in the salinity anomaly curve between 300 

 and 400 meters, might satisfy the deeper part of the salinity 

 anomaly curve if further downward movement resulted from the 

 mixing near the upper part of the continental slope. It does not, 

 however, offer a clear explanation of the pronounced positive 

 temperature anomaly at 600 meters. 



The temperature maximum of the Labrador Current occurs at 

 a depth of about 600 meters and is a part of the warm water 

 tongue, which in a vertical section across the Labrador Current 

 characteristically extends downward toward the beach at inter- 



42 



