Methodology of CRW Ocean Acidification Products Computation of Sea Surface Total Alkalinity Fields

Estimates of sea surface total alkalinity (A_T) were derived according to the relations offered by Lee et al. [2006] for surface waters using a simple empirical equation of the form:

A_T = a + b(SSS - 35) + c(SSS - 35)² + d(SST - 20) + e(SST - 20)²

To compute daily fields of A_T the (sub)tropical form of the algorithm was applied to SST and SSS datasets as described under the sea surface pCO_2,sw methods and detailed in Gledhill et al. [2008].