Strong temperature gradients in the ice age North Atlantic Ocean revealed by plankton biogeography

This study evaluates Last Glacial Maximum (LGM) climate simulations using the macroecological principle of decreasing community similarity with increasing thermal distance. Analysis of planktonic foraminifera assemblages reveals inconsistencies between simulated and observed ice age seawater temperatures, particularly in the subpolar North Atlantic. The stronger cooling indicated by the species assemblages is more consistent with simulations featuring a reduced Atlantic meridional overturning circulation (AMOC). This approach demonstrates the value of macroecology in diagnosing past climate simulations and highlights challenges in resolving the spatial imprint of global change in climate models.

Lukas Jonkers, Thomas Laepple, Marina C. Rillo, Xiaoxu Shi, Andrew M. Dolman, Gerrit Lohmann, André Paul, Alan Mix, Michal Kucera