186 MARION AND GENERAL GREENE EXPEDITIONS 



tween the more central regions of the Labrador Sea and the more 

 stable waters inshore. The consequent circulation reaching a maxi- 

 mum at the end of winter results in a corresponding intensification 

 of mixing between the heavy winter wat«r and the higher-tem- 

 peratured^ water from the margins. As mixing continues, accord- 

 ing to our view, density gradients flatten and the intermediate water 

 in such a self -compensating system is proportionately warmed, and 

 temperature differences rapidly disappear as thermal homogeneity 

 is approached. The volume of the current between GodthaaVs sta- 

 tions 24 and 22 at the end of Avinter was computed on the assump- 

 tion that station 24 (fig. 136) lay within the region of bottom- water 

 formation, and that station 22 was on the outer margin of same. 

 A volume of 33.5 million cubic meters per second toward the south 

 with a mean surface velocity of 14 centimeters per second indicates 

 that a current so hypothesized is of reasonable volume and velocity. 



A temporary retardation of the frigid portion of the Labrador 

 Current during the colder months of the year when Baffin Bay 

 becomes ice filled may also be a factor involved in regulating the 

 thermal state of the intermediate water of the Labrador Sea. 



The intermediate water is also apparently warmed on its under 

 side near the 2,000-ineter level where in several of the sections this 

 evidence is disclosed by slight temperature maxima (fig. 139). The 

 component of this mixture probably arises in the Irminger-Atlantic 

 water which on sinking spreads oiit in these depths more than in 

 others as the perennial deep water acts as a virtual bottom. 



An area of temperature-minimum is found in practically all of 

 the vertical sections of the intermediate water centered at an aver- 

 age depth of 1,375 meters. The 3.17° C. isotherm (fig. 147) and 

 its corresponding 34.88%o isohaline, embrace what has been here- 

 tofore designated as typifying intermediate water. Particular im- 

 portance is attached to the temperature minimum in the interme- 

 diate water, it being considered reminiscent of winter chilling, this 

 core being farthest removed from the warmed sides and the under- 

 side remains the coldest. The minimum temperatures when plotted 

 in horizontal projection coincide with the shaded area shown on 

 figure 149 and extend eastward past Cape Farewell (if the Meteorh 

 observations are utilized) between the Atlantic and Irminger Cur- 

 rents. It is interesting to note that in the longitude of Cape Fare- 

 well where a temperature minimum of the intermediate water was 

 observed in March (see Meteor's station 121) it had entirely dis- 

 ai)peared bv August of the same year. (See General Greene's sta- 

 tions 2019-2009-2003-1996.) 



THE DEEP WATER ^ 



That Irminger-Atlantic water as it flows cyclonically around the 

 Labrador Basin progressively sinks, has been demonstrated by figures 

 132, 133, and 134. After cabbeling to depths greater than 2,000 meters, 

 depending upon the depth of the basin, this water approaches the 

 region of heavier bottom water over which it apparently spreads and 

 into which it slowly mixes. This is the usual summertime distribu- ^ 



