5b. Total CO2 Concentration along the 88°W Section
The distribution of total CO2 concentration in deep water along the 88°W meridian (P-19 section) is shown in Fig. 13. Along this section, a CO2 maximum layer is observed at depths centered around about 2000 to 2500 meters, which is somewhat shallower than the corresponding maxima observed along the 135°W and 150°W sections. Since the section extends to the northern hemisphere, 13°N, the maximum CO2 concentration is greater along this section (i.e., up to 2370 mol/kg) than that found along the other sections. However, the CO2 concentrations for the CO2 maximum layer at corresponding latitudes are similar to those along the 135°W and 150°W sections. While a single tongue of the CO2 maximum water is observed continuously from 5°S to 48°S along the 135°W section, the CO2-maximum tongue along the 88°W section is split into two segments as shown by the 2300 µmol/kg contour located at about 30°S. The northern segment of this section is in the Peru Basin while the southern segment is in the Southeast Pacific Basin of the Southern Ocean, and these basins are separated by the Chile Rise. It appears, therefore, that flow paths of deep waters and hence the distribution of CO2 in deep waters are affected critically by the sea floor topography which influences the circulation pattern.