Salinity of the Ocean, its Variation in Oceanic Space and in Time 



175 



along the entire spreading area for the entire western section through the Atlantic 

 Ocean (Fig. 78). This distribution has a clear similarity to that presented in Fig. 48 

 which shows the radial and turbulent spread of a particular water mass into surround- 

 ing waters. This distribution also corresponds to the processes of spreading in a so- 

 called "jet" (Freistrahl) (Prandtl, 1926; Tolmein, 1926; Ruden, 1933). Figure 79 



100 X 



80 



*600 +800 



60 



40 



80 



0^ 



T" 



Fig. 79. Distribution of salinity relative to the minimum in the core layer of the subantarctic 

 intermediate water along the western side of the Atlantic for different vertical cross sections. 



shows for each cross-section the distribution of salinity relative to the minimum in 

 the core and shows that the general distribution is the same for all cross-sections and 

 that the processes involved mu: t be essentially the same, geometrically and mechani- 

 cally, as in a "jet". 



An accurate knowledge of the salinity values throughout the entire region of the 

 subantarctic intermediate water allows the vertical distribution of the quantity Ajpu 

 to be calculated from the equation on p. 106 for all cross-sections. 



A rough calculation shows at once that vertical mixing and advection are able to 

 maintain the tongue-formed salinity distribution stationary in the subantarctic inter- 

 mediate current. The vertical salinity distribution at a distance of 8000 km from the 

 zeio point of the western section (about 13° S.) is as follows 



-300 



+ 200 +100 



100 



-200 



-300 -400 (m) 



salinity in %o 



vertical gradient 

 (per 100 m) 



34-71 



0-54 



0-42 



O^S" 



0-44 



0-52 



0-60 



0-69 



-017 



-012 



-004 



+006 +008 +008 +009 



Considering a vertical water column of 1 cm^ base between +250 and —250 m the 

 inflow of salt into the column from above and below is shown in Fig. 80, taking A = 

 4gcm-isec-^ The salt gain in the entire volume (5 x 10* cm^) thus amounts to 

 1-00 X 10"^ g/sec or 8-64 mg/day. Without an advective outflux this continuous gain 

 of salt would soon eliminate the salinity minimum of the subantarctic intermediate 

 water. Through the left-hand (southern) boundary of the water column (with an area 

 of 5 X 10* cm2) there enters an amount of salt of 5 x 10* X m • .s X 10"^ g, where u 



