GEOCHEMISTRY AND PHYSICS OF OCEAX CIRCULATION 



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adequate model is not possible. A grossly simplified model pre- 

 serving only the main features of the system is still useful, however. 

 The ocean-atmosphere system has been broken up into eight 

 reservoirs which are considered to be internally well mixed. The 

 reservoirs chosen are defined in Table VIII. The cold region north 

 of 55° N in the Atlantic and north of the Bering Straits is defined 

 as the Arctic and that south of 55° S as the Antarctic reservoir. 

 The mixed layer of the oceans assumed to extend to 100 m depth 

 is broken into three parts, North Atlantic, South Atlantic, and 

 Pacific -f Indian Oceans. Existing radiocarbon data allow no 

 detailed division of the large Pacific and Indian Ocean systems. 

 The area presented by each reservoir to the atmosphere and the 

 total carbon stored in each reservoir are shown in the last two 

 columns. A diagram of the model is given in Fig. 8. The mixing 

 between reservoirs is assumed to be as shown by the arrows. The 

 Atlantic is characterized by a northward transfer at the surface 

 and southward transfer at depth. The Pacific -f Indian Ocean 

 surface and deep reservoirs communicate only at the south end of 

 the ocean. The x^tlantic and Pacific communicate through the 

 Antarctic. No mixing is assumed across the main thermocline in 

 either ocean. The exchange of COo between the ocean and atmos- 

 phere is assumed to be independent of geographical location. 

 Measured values are used to estimate the average AC^"* value 



Table VIII. Oceanic Mixing Model 



Assume uniform AC'* in each reservoir. 



