Global relationships of total alkalinity with salinity and temperature in surface waters of the world's oceans

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 μmol 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.