DOTpaleo

In the DOTpaleo project, we combine reconstructions of past deep ocean temperatures with climate model simulations to better understand the behavior of the climate system during extreme greenhouse conditions in the Paleocene and Eocene (65-35 million years ago). At this time, CO concentrations were much higher than today, leading to a much warmer climate and the absence of permanent ice sheets. We aim to better understand how the climate system operates under such conditions. For our temperature reconstructions, we employ an isotopic method in marine microfossils (foraminifera), called clumped isotope thermometry. We build on our recent work in the North Atlantic, where we found surprisingly high and variable deep ocean temperature during this early time period. This previous record is being complemented with more detailed analyses at this location and other sites in the world’s ocean. The reconstructions are combined with climate model experiments with the Norwegian Earth System Model (NorESM) that investigate the climate response to different combinations of CO and probable past ocean gateway configurations.