27 through 31 show the salinity distribution in this section found 

 during the postseason cruises of 1939, 19^0, 1941, 1948, and 1949 

 respectively. The maxinnnn salinity in the core of the Irminger Cur- 

 rent component of the "West Greenland Current at this section ob- 

 served during these cruises was 35.04, 35.03, 35.05, 35.04, and 

 34.97 °/ respectively. The remarkable uniformity of the maximum 

 salinity of this water has come to be regarded as a characteristic 

 of this part of the "West Greenland Current and the extent of the 

 cross sectional area has been sufficient that the spacing of the sta- 

 tions designed to permit the construction of a good vertical section 

 of anomaly of specific volume has given short enough station intervals 

 to reveal the shape of this warm and salty core. 



The temperature is a more effective variable than the salinity of 

 the Irminger Current water. It is therefore that the drop in the 

 salinity shown in figure 31 compared with figures 27 through 30 is 

 such a striking demonstration of the almost total absence of Irminger 

 Current water off Cape Farewell in 1949. Physically and climatolog- 

 ically it is the variation in temperature, rather than salinity, of this 

 warm water core that is of importance. The drop in temperature of 

 the core accompanying the drop in salinity was sufficient to increase 

 its density by about 0.10 in o-^ above the usual values. As it is the 

 Irminger Current component that makes the "West Greenland Current 

 a warm current, and as the "West Greenland Current supplies most 

 of the water-borne heat to Baffin Bay and forms the relatively warm 

 offshore part of the Labrador Current, any prolonged deficiency in 

 Irminger Current water reaching Cape Farewell can be expected to 

 have serious repercussions in its effect on the extent and duration of 

 the ice cover in Baffin Bay and the mortality rate of bergs in the 

 journey from their parent glaciers in Greenland to the position of 

 their ultimate disintegi'ation near the steamer lanes in the vicinity 

 of the Grand Banks. 



In earlier bulletins of this series it has been noted that while the 

 year to year fluctuations in the ^'olume of flow of the "\"\"est Greenland 

 Current off Cape Farewell are so large as to mask any regular sea- 

 sonal fluctuation, the mean temperature of this current seemed to 

 have a marked seasonal increase during the summer months. Because 

 of the rapid increase, in spite of the fact that a relatively small part 

 of the volume of water involved is exposed to the surface, it would 

 seem more reasonable to expect the fluctuation to be the result of a 

 changing proportion of the parent currents which join northeastward 

 of Cape Farewell to make up the "West Greenland Current. A sea- 

 sonal fluctuation in the mean temperature of the "\Yest Greenland 

 Current can result from seasonal fluctuations in the relatively cold 

 East Greenland Current or the relatively warm Irminger Current, 

 or both. 



83 



