A simple function of sea surface salinity (SSS) and temperature (SST) in the form AT = a + b (SSS - 35) + c (SSS - 35)2 + d (SST - 20) + e (SST - 20)2 fits surface total alkalinity (AT) data for each of five oceanographic regimes within an area-weighted uncertainty of ¿8.1 ¿mol kg-1 (1σ). Globally coherent surface AT data (n = 5,692) used to derive regional correlations of AT with SSS and SST were collected during the global carbon survey in the 1990s. Such region-specific AT algorithms presented herein enable the estimation of the global distribution of surface AT when observations of SSS and SST are available.