can be observed in figure 20. Again repeating 



for the salt transport. : 

 Section F, net south : 371.5 X lO^ gms/sec 

 ^ . ^ , +731.1X108 gms/sec 



Section D, net east : ii02.6X 10« gms/sec 



The outflow south from this area through sec- 

 tion C shows a salt transport, of 1198.2X10* 

 gms/sec. In this area, the in-and-out figures of 

 the volume and salt transport agree within 8 

 percent. 



The relatively close agreement of the flow fig- 

 ures, to and from these bounded areas supports 

 the circulation and flow computations deduced 

 from the dynamic heights. It reaffirms the valid- 

 ity of the dynamic method, particularly in shal- 

 low water. A 10 percent accuracy is as good as can 

 be expected in view of the great number of as- 

 sumptions, technique errors, and nonmass related 

 flow forces. It is singularly reassuring, if not 

 surprising, that the percentage agreement shown 

 above is as close as it is. 



The water exchange through the Hudson Strait 

 entrance, north and south of Resolution Island 

 shows a net flow, to the east, of 1.64:Xl0^mVsec. 

 This volume flowout, accounts for almost 50 per- 

 cent of the net flow to the south through section 

 C. As pointed out in the previous section, high- 

 salinity water flows into Hudson Strait and is 

 mixed, midway up the strait, with low-salinity 

 water moving out of the Hudson Bay, Foxe Chan- 

 nel area. The mean salinity of the net. westward 

 water flow into the Hudson Strait entrance is 

 33.36%o and the mean salinity of the net outflow 

 is 32.72%o. A simple mixing calculation will 

 show the required salinity of the mixing con- 

 stituent that combines with the inpouring Baffin 

 Land Current water, resulting in the character- 

 istic cold, low salinity water of the shelf portion 

 of the Labrador Current. Referring to figure 20, 

 across the entrance to Hudson Strait, the follow- 

 ing equation is applied : 



V,Mt = V,Mi + V.M. 

 where 



Vt = total volume flowout, 4.78 X lO'^mVsec 

 Mt = mean salinity out, 32.72%o 

 Vi=volume flow in, 3.14 X lO^mVsec 

 Mi=mean salinity in, 33.36%o 

 V2 = volume flow of mixing constituent, 1.64 X 



lO^mVsec 

 Ms = mean salinity of mixing constituent 



Solving the above equation results in a value for 

 Mo of 31.49%o. This value falls very nicely with- 

 in the approximate limits of the salinities of the 

 water masses available within Hudson Strait, dis- 

 cussed in two previous sections, which undoubt- 

 ably combine and form the mixing constituent for 

 subsequent combination with the Baffin Land Cur- 

 rent water. 



The volume flow of section B is quite low com- 

 pared to that through section C. The mean salin- 

 ity of sections B and C are quite comparable, how- 

 ever the volume flow is only half that of C. Tliere 

 are several possible explanations for this disagree- 

 ment: 



First, the depth of section C is greater by at 

 least 100 meters than section B. If it is assumed 

 that tlie gradient pressure force of section C is act- 

 ing along prescribed geostrophic principles, the 

 strong flow south, induced in section C, is forced 

 through section B, resulting in a swift barotropic 

 flow and not detectable by an examination of the 

 mass distribution. 



Second, the situation may exist in section C, 

 where the outflowing tidal pulses, speculated on 

 previously, cause a pileup of the light water. This 

 is indicated by the dynamic height contours which 

 intersect the coast of Labrador. In this situation, 

 the time lag of the adjustment period is such that 

 this mass or slug of light water is at least a semi- 

 permanent feature in the area. Therefore as 

 found, the geostrophic movement south is slow 

 through section B, but over a given time period is 

 sufficient to carry off the periodic tidal buildup 

 of the water emanating from Hudson Strait at 

 section C. This concept would still allow the use 

 of the dynamic method for examining the pres- 

 sure-mass distribution flow tendencies. One sup- 

 porting point for this argument is that the total 

 outflow from Hudson Strait, 1 .64 X l()''mVsec, is 

 only slightly less than the 1.68X lO'^rnVsec net 

 southward flow through section B. The limited 

 southward flow from section F, which appears to 

 be continuous through section C and B has prop- 

 erties within the defined water mass but on the 

 warm, higher salinity end. This can be seen from 

 the T-S curves of figures 12 and 14. Being 

 warmer and saltier, and in proximity with the 

 boundary Labrador Sea water, makes it more sus- 

 ceptible to receiving heat and salt, as it moves 

 south thereby removing good portions of its 

 volume flow from the defined water mass analyzed 

 prior to its arrival at sectioTi B. 



13 



