Influence of plate reference frames on deep-time climate simulations

Abstract

Deep-time paleogeographic maps can be constructed on plate tectonic models that utilize mantle or paleomagnetic reference frames. Different reference frames result in divergence in plate positions, which are important boundary conditions in deep-time paleoclimate simulations. Here, using three early Eocene paleogeographic maps, we demonstrate the impact of reference frames on the simulated atmospheric circulations with the Norwegian Earth System Model. With these three maps, one using the paleomagnetic and the other two using the mantle reference frame, our simulations show significant differences in the simulated general climatic characteristics, especially in the Pacific region. The paleomagnetic reference frame leads to a narrower and stronger Pacific Walker Circulation, more asymmetrical Hadley Circulations, and a stronger subtropical high in the North Pacific, compared to the mantle reference frame.