Glacial to Interglacial Changes in Ocean and Atmosphere Chemistry

Abstract

CO₂ content of the atmosphere increases between glacial and interglacial times, have been postulated from gas content studies of long ice cores from Greenland and Antarctica. A hypothesis for this increase involves the loss of phosphorous from the sea to the shelf sediments during the early postglacial transgression of sea level, reducing the amount of plant matter formed per unit of upwelled water and thereby increasing the CO₂ pressure in surface water and the atmosphere. Evidence in support of this hypothesis is obtained from the ¹³C results for benthic and planktonic foraminifera. Changes in the difference between warm surface water and mean oceanic ^δ13C values reflect changes in the oceanic PO₄ to ΣCO₂ ratio.