Chapter 16 — FUNDAMENTALS OF OCEANOGRAPHY 



ARCTIC 



ANTARCTIC 



Figure 16-11. — Simplified general circulation pattern of the Atlantic Ocean. 



Mediterranean Water flowing along the bottom 

 of the Strait of Gibraltar mixes with surrounding 

 Atlantic Water and spreads out between sur- 

 faces below the Antarctic Intermediate Water. 

 The spreading of the Red Sea Water is not 

 so well defined but may be recognized over 

 large parts of the equatorial and western regions 

 of the Indian Ocean by its higher salinity values. 



Deep and Bottom 

 Water Masses 



Below the Intermediate Water the deep ocean 

 basins are filled by Deep and Bottom Water 

 of high density. These water masses are formed 

 near the Antarctic Continent and in the high 

 latitudes of the northern oceans. The spreading 

 of these Deep Water masses are detectable in 

 areas outside their source regions all around 

 the world. More information on the spreading 

 of Deep and Bottom Water is presented in the 

 following discussion of oceanic circulation. 



CIRCULATION 



Figure 16-11 serves to illustrate a number 

 of interesting features regarding circulation of 

 the ocean waters. 



Notice that the deep water flows outward 

 along the bottom from the Antarctic Continent. 



This movement results in the existence of 

 Antarctic Bottom Water, Circumpolar Water, 

 and Antarctic Intermediate Water not only in 

 the Antarctic regions but also throughout the 

 southern portions of the oceans as these high 

 density Deep Water masses move away from 

 their source region. This outward motion of 

 water masses is not only characteristic to the 

 Antarctic region but occurs with Arctic Deep 

 Water, Mediterranean Water, and Red Sea 

 Water as well. 



As the Deep Water and Bottom Water formed 

 by sinking and spreading of HIGH DENSITY 

 water in the Subarctic and Subantarctic regions 

 of the Atlantic and Pacific are modified by 

 HIGH SALINITY water flowing out of the Red 

 Sea into the Indian Ocean, a circulation such 

 as that illustrated in figure 16-11 is established 

 in the oceans. The northern oceans' Deep Water 

 and Bottom Water flow away from their sources 

 and are replaced by surface and intermediate 

 waters returning the waters toward their 

 originating areas. 



Many secondary circulations are created 

 within this simplified general circulation. For 

 example, the Antarctic Bottom Water which 

 contains relatively low salinity flows northward 

 along the bottom to near 35°N. This influx of 

 low salinity water causes the salinity of the 

 bottom water in the northern oceans to 



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