Millennial-scale oceanic CO2 release during marine isotope stage 3

Abstract

<p>During the last glacial period atmospheric CO<sub>2</sub> and temperature in Antarctica varied together on millennial timescales, with CO<sub>2</sub> abruptly increasing by 10-20 ppm in <1000 years in some cases. The exact causes of these rapid CO<sub>2</sub> changes during a cold glacial climate remain unclear. Here we examine the role of ocean carbon storage and atmospheric exchange by applying the boron isotope-pH (CO<sub>2</sub>) proxy to Globigerina bulloides from core site TAN110628 located in the Pacific Sector of the Southern Ocean.  By reconstructing the surface carbonate system at TAN110628 at high temporal resolution (1 sample every 1 kyr) from 30 to 64 kyr we are able to fully constrain the nature of carbon leakage from the Sub Antarctic Zone of the Southern Pacific Ocean associated with these millennial-scale changes in atmospheric CO<sub>2</sub>.  This provides unique insights into the causes of abrupt changes in atmospheric CO<sub>2</sub> during Marine Isotope Stage 3 and the last termination. </p>