The global distribution of surface AT for August
calculated using the derived AT algorithms of Table 1 applied
to climatological SSS and SST fields [Conkright et al., 2002]
is shown in Figure 1. The surface AT field shows broad
maxima in the central gyres centered at about 25 north and
south of the Equator, similar to the pattern for salinity. Such
strong salinity-dependent trends in surface AT result from the
fact that the concentrations of the key chemical species (i.e.,
HCO3
, CO3
2, and B(OH)4
) that contribute to AT proportionally
increase with increasing salinity, and thus the ratio of
AT to salinity is approximately constant throughout the
(Sub)tropics.