212 [TS]-relationship and Connection with Mixing Processes and Large Water Masses 



considerably more detailed treatment of problems briefly outlined here has been given 

 by WiJST (1936) using this data and applying the so-called "core-layer method". The 

 characteristic properties of a water mass are retained in the core layer and an analysis 

 of changes in the core layers is therefore of decisive importance for an investigation 

 of the spreading of a water type. The most difficult and essential part of such an in- 

 vestigation is the accurate determination of the core layer of each water type at each 

 station from the vertical distribution of the different oceanic factors. A single factor 

 will not necessarily be best for the characterization of the core layer. Thus salinity was 

 found to be the most suitable indicator for the subantarctic intermediate water and 

 also for the upper North Atlantic deep water which gets in the North Atlantic a 

 continuous supply from mediterranean water, while the potential temperature is used 

 for antarctic bottom water and oxygen content for Lower Deep Water (intermediate 

 maxima in oxygen content). The spreading of a water type can be found by following 

 the appropriate indicator. The subantarctic Intermediate Water can be taken as an 

 example, to show the use of the "core layer method"; here the intermediate salinity 

 minimum between 50° S. and 20° N. is an excellent indicator. The depth of this 

 minimum and its salinity, temperature and oxygen content can be evaluated from the 

 vertical curves of all stations. This water type sinks as shown by the analysis at the 

 southern oceanic Polar front. The 100 m depth line runs parallel to and immediately 

 to the north of it, and from here the depth of the core layer is shown by the isobath 

 on Fig. 100. From 45° S. to 39° S. the core lowers continuously and rapidly from 100 m 

 down to 800 m and reaches its greatest depth on the average at about 900 m between 

 37° S and 30° S. It then rises to about 800 m, falling again to 900 m or more north 

 of 10° N. A chart of the S distribution shows that rapid lowering of the core goes 

 parallel with a rapid rise in sahnity from 33-9%o to 34-2%o ; beyond this region the meri- 



3V3%o 



35-0%< 



Fig. 99. [r5]-curves for four "Meteor" stations along a western longitudinal section in the 

 Atlantic in the area of the subantarctic intermediate water (the figures give depths in 100 m- 



units). 



