inside Cape Chidley. A comparison of this water 

 mass with tliat found outside tlie strait will be 

 made in a following section. 



PROPERTY DISTRIBUTIONS 



As stated in the introduction, the main interest 

 of the expedition was to trace, and examine the cir- 

 culation of the cold low salinity water that makes 

 up what is observed as the Labrador Current off 

 the Grand Banks of Newfoundland. The analy- 

 zation of the data herein is therefore confined to 

 the consideration of water of this nature. For 

 the purposes of this analysis, an arbitrary water 

 mass was defined on the basis of l7-year mean 

 temperature-salinity relationships. Shown in fig- 

 ure 9 are tlie mean T-S cui-ves of the three basic 

 water masses found off the Grand Banks. These 

 means are based on International Ice Patrol Sur- 

 veys during the period 1948 to 1964. The point 

 located on the T-S cui-ve for Labrador Current 

 water defines the limits for analysis of water which 

 has a temj^erature of less than 2° C. and a salinity 

 of less than 34.3%o. Tliis point roughly confines 

 this water to the upper 200 meters. Using a limit- 

 ing definition such as this, certain areas contrib- 

 uting water to the volume flow of the Labrador 

 Current are immediately excluded from consider- 

 ation as sources of the cold portion of the current. 

 The boundaries of this cold water are also well 

 defined in the property sections. Only about 5 

 percent of the cold, low salinity water found, 

 failed to fulfill the T-S requirements. That is, if 

 the water was less then 2° C. it was almost always 

 less than 34.3%^ in salinity. 



These defined limits encompass broad current 

 areas, above the shelf, just inside the swifter flow- 

 ing boundaiy current. As mentioned previously, 

 this broad current area provides the cold environ- 

 ment in which the iceljergs are transported south. 

 It is also the area of the light water, variations in 

 which cause the volume and velocity fluctuations 

 in the southward flowing current. 



The salinities and temperature obtained in the 

 various sections vary quite significantly within 

 the above definition. Tliese variations provide the 

 basis for some of the conclusion drawn in subseqent 

 sections herein. 



Figures 10 througli 15 present the temperature 

 and salinity distribution along the sections ob- 

 tained during the expedition. Inserts in each fig- 

 ure give tlie relative locations of the individual sec- 

 tions. The 2° C. limit is shown by lx)ld lines on 



each of the temperature sections. As can be seen, 

 the temperature gradients both horizontal and 

 vertical, become much stronger above the 2° C. 

 isotherm. This provides a useful boundary in the 

 analysis of these water masses. 



Figures 10 and 11 show the water properties in 

 the northern reaches of the expedition and includes 

 the line of stations occupied down the center of the 

 Labrador Sea. Section H, taken halfway across 

 the Davis Strait, shows large quantities of cold 

 low salinity water. This is the only section where 

 a considerable disagreement exists between the 

 relative position of the 2° C. isothenn and the 

 34.3%o isohaline. In this section, water of higher 

 salinity exists which is much less than 2° C. in 

 temperature. Significant here, however, is the ob- 

 servations that this disagreement exists well below 

 200 meters and probably represents a water mass 

 of Baffin Bay Basin origin. The section imme- 

 diately to the south, section G has a much shal- 

 lower depth, thus this more saline, denser water is 

 prevented from moving south into the area of 

 interest. 



Connecting the sections G and H in the west, 

 figures 10 and 11 is section I. Because this section 

 is located in the center of the northern end of the 

 Labrador Sea, it crosses an east to west circulation 

 of portions of the West Greenland Current as well 

 as the eastern edge of the southward flowing Baffin 

 Grand Current. To be noted in this section is the 

 tongue of flow temperature water emanating from 

 Baffin Bay. This tongue narrows and all but dis- 

 appears to the south in this section. This is be- 

 cause of the east-to-west drift, encountered by the 

 outflowing Baffin Bay water which causes a dis- 

 placement to the right towards the coast and out of 

 the limits of section T. 



To the south, section F shown in figures 12 and 

 13, running east from Resolution Island shows a 

 lack of water less than 2° C. Water of a salinity 

 of less than 33.0%^ was totally missing. The sec- 

 tions to the north had great quantities of water 

 less than 2° C. and 33.0%^. This supports the cir- 

 culation regime observed in the dynamic height 

 and isentropic charts where little of the water 

 from the north appears to pass through this sec- 

 tion. The water in this section is totally different 

 than that from the north and appears to be sup- 

 plied by water from the east. One small offshore 

 cold core, and a slightly larger core of cold water 

 near Resolution Island are found in the section. 



