THE OCEANIC SALT PUMP: DOES IT CONTRIBUTE TO THE GLACIAL-INTERGLACIAL DIFFERENCE IN ATMOSPHERIC CO2 CONTENT?

Sea ice formation drives salt from the surface to the deep sea. In so doing it lowers the salinity of polar surface waters. We show here that this reduction in turn lowers the CO2 partial pressure of polar surface waters and hence also of the atmosphere. We propose that during glacial time when more sea ice existed, this pumping action may have been stronger. If so, part of the glacial to interglacial atmospheric CO2 content change observed in ice cores may have been driven by the ocean's salt pump.