293
The Carbonate System
The values in the deep waters increase from the North Atlantic (2180 μmol kg –1 ) to the
North Pacific (2380 μmol kg –1 ) because of the oxidation of organic carbon and dissolution
of CaCO 3 . The values of TCO 2 and TA correlate very well with each other and can be used
to characterize various water masses (see Figure 7.33).
Due to the buffering effect of seawater, only a small amount of CO 2 needs to be transferred
to the oceans to restore the equilibrium between the atmosphere and surface. This buffering
is called the Revelle factor (R). It is the ratio of the fractional change in the partial pressure of
TA (µM)
2100
2200
2300
2400
2500
Depth (m)
0
1000
2000
3000
4000
5000
N. Atlantic
N. Pacific
Figure 7.26
The total alkalinity (TA) as a function of depth in the Atlantic and Pacific Oceans.
NTA (µM)
2300
2350
2400
2450
2500
Depth (m)
0
1000
2000
3000
4000
5000
N. Atlantic
N. Pacific
Figure 7.27
The normalized total alkalinity (NTA) as a function of depth in the Atlantic and Pacific Oceans.