Use of the boron partition coefficient 'KD' and B/Ca from planktonic foraminifera in the estimation of past seawater pCO2

Abstract

We assess the usefulness of the empirical boron partition coefficient, KD and B/Ca measured from planktonic foraminifera in estimation of pCO2 using three different relationships between KD 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 KD relationships lead to assorted results which suggests that the KD approach may not be suitable in paleo-pCO2 reconstructions.