RECONSTRUCTION OF ATMOSPHERIC CO2 FROM ICE-CORE DATA AND THE DEEP-SEARECORD OF ONTONG-JAVA PLATEAU - THE MILANKOVITCH CHRON

We provide a reconstruction of atmospheric CO2 from deep-sea sediments , for the past 625 000 years (Milankovitch chron). Our database consis ts of a Milankovitch template of sea-level variation in combination wi th a unique data set for the deep-sea record for Ontong Java plateau i n the western equatorial Pacific. We redate the Vostok ice-core data o f Barnola et al. (1987). To make the reconstructions we employ multipl e regression between deep-sea data, on one hand, and ice-core CO2 data in Antarctica, on the other. The patterns of correlation suggest that the main factors controlling atmospheric CO2 can be described as a co mbination of sea-level state and sea-level change. For best results sq uared values of state and change are used. The square-of-sea-level rul e agrees with the concept that shelf processes are important modulator s of atmospheric CO2 (e.g., budgets of shelf organic carbon and shelf carbonate nitrate reduction). The square-of-change rule implies that, on short timescales, any major disturbance of the system results in a temporary rise in atmospheric CO2.