Use of the Boron partition coefficient ‘K_D’ and B/Ca from planktonic foraminifera in the estimation of past seawater pCO₂

Abstract

We assess the usefulness of the empirical boron partition coefficient, K_D and B/Ca measured from planktonic foraminifera in estimation of pCO₂ using three different relationships between K_D and temperature derived from various studies. Two sediment cores spanning the last 22 kyr were utilised, one from the intense CO₂ source region of the Western Arabian Sea (WAS) and another from the Eastern Arabian Sea (EAS). The sea-air difference in pCO₂ at these sites shows results contrary to the present day scenario. Moreover the reconstructions using the three K_D relationships lead to assorted results which suggests that the K_D approach may not be suitable in paleo-pCO₂ reconstructions