of the sections to the north. This indicates that a 

 supply of less saline water is being introduced into 

 the circulation of the area. The eastern ap- 

 proaches to this section are eliminated as the source 

 due to the higher salinity of the Labrador Sea. 

 The northern approaches obviously do not contain 

 any significant quantities of low-salinity water. 

 Only the waters outflowing from Hudson Strait 

 are comparable in mean salinities with the waters 

 of section C and section B further to the south. 

 A clear pattern appears in this mean salinity dis- 

 tribution. High-salinity water from the north 

 appears to turn into Hudson Strait, in the north- 

 ern half, while lower salinity water is put into the 

 system from Hudson Strait in the southern half. 

 Campbell (1958) found the circulation in Hud- 

 son Strait to be westward along the northern coast 

 and eastward along the southern coast. He also 

 found a recurving and a mixing of the water flow- 

 ing along the northern shore, with the water to the 

 south. This occui-s roughly midway along the 

 strait and provides the mechanism for altering the 

 high salinity water flowing in, by mixing it with 

 very low salinity water flowing out of Hudson 

 Bay. Campbell (1958) shows the salinity dis- 

 tribution, at 20 meters, for October 1955 and July 

 1956, in Hudson Strait and the outlet of Hudson 

 Bay. He found a high-salinity inflow into the 

 strait from the east, greater than 33.0%o and an 

 outflow from Hudson Bay of less than 30.0%o. 

 These would be the necessary concentrations for 

 the mixing and formation of the mean salinities 

 observed flowing eastward through the entrance 

 of Hudson Strait. Contributions from other 

 sources in the Hudson Bay, Hudson Strait area 

 are also cited by Campbell. Their existence elim- 

 inates any simplified or unique mixing ratios be- 

 tween BafHn Land Current water and the resident 

 water of HudscFii Bay. Campbell shows the area 

 of recurvature of the inpouring Baffin Land Cur- 

 rent and subsequent mixing with the eastward 

 moving water of Hudson Strait, to be east of the 

 majoi-, resident water sources. The sum total of 

 the low salinity contributions from Hudson Bay 

 and Foxe Channel located just north of Hudson 

 Bay, form the major water masses which combine 

 witli the inflowing Baffin Current, modifying it 

 into a characteristic water mass. Thus the cir- 

 culation system in Hudson Strait appears to ab- 

 sorb tlie high salinity water, mix it with very low 

 salinity water, and eject this mixture as the char- 



acteristic low salinity water which forms the shelf 

 portion of the Labrador Current. 



VOLUME FLOW 



Figure 20 presents the summarized volume flow 

 and salt transport values, in each direction, for 

 the defined water mass. Presented also are the net 

 transports. The question of the validity of the 

 dynamic height calculations was raised in a pre- 

 vious section. The limitations of the dynamic 

 method are carried over into the volume flow and 

 salt transport calculations because they are based 

 on the dynamic heights. The areas bounded by 

 sections G, E, F, and F, D, C should fulfill the 

 requirements of conservation of mass. That is to 

 say, the volume of water and salt flow into a par- 

 ticular closed area, should equal the volume flowing 

 out. The particular area defined above, and shown 

 in figure 20 are bounded either by the sections 

 listed, land masses, or the Labrador Sea which 

 falls outside the defined water mass characteristics 

 of less than 2° C. and 34.3%,,. 



The sections of G, E, and F, the Baffin Island 

 coast, and the 2° C. isotherm, shown in figure 20, 

 define a closed area which should fulfill the require- 

 ments of mass consen^ation. First looking at the 

 net volume fiow values of figure 20. 



Section G, net south : 1.85 X 10«mVsec 

 -0.59XlO«mVsec 



Section E, net west: i.gBXWmVsec 



This figure compares with net volume trans- 

 port south through section F of 1.07xlO«mVsec. 

 Repeating these computations for the salt trans- 

 port : 



Section G, net south : 638.0 X 10» gms/sec 

 - 198.9 X10« g ms/se c 



Section E, net east : 439.1 xlO« gms/sec 



This compares witli tlie net salt transjjort soutli 

 through section F of 371.5 X lO^gms/sec. These 

 in-and-out figures agree within 15 percent for 

 botli volume and salt transport. 



Extending these comparisions to tlie area south 

 of Resolution Island bounded by sections F, D, and 

 C and the 2° C. isotherm to the east, the following 

 calculations are made : 



Section F, net south : 1.07X WmVsec 

 + 2.23 X lO^mVsec 



Section D, net east : " .. 30 x 10«mVsec 



Comparing this figure with the flow south 

 through section C, the value of 3.57xl0''mVsec 



12 



