Ocean Model Formulation Influences Transient Climate Response

The transient climate response (TCR) is 20% higher in the Alfred Wegener Institute Climate Model (AWI-CM) compared to Max Planck Earth System (MPI-ESM) whereas equilibrium sensitivity (ECS) by up 10% AWI-CM. These results are largely independent of two considered model resolutions for each model. coupled CMIP6 models share same atmosphere-land component ECHAM6.3 developed at Meteorology (MPI-M). However, different ocean models, namely MPIOM sea ice-ocean MPI-M and FESOM Institute, Helmholtz Centre Polar Marine Research (AWI). A reason TCR related heat uptake greenhouse gas forcing. Specifically, AWI-CM simulations show stronger surface heating than MPI-ESM while latter accumulate more deeper ocean. vertically integrated content increasing slower configurations high latitudes. Weaker vertical mixing seems be key these differences. strongest difference occurs inside Weddell Ross Gyres northern North Atlantic. Over Atlantic, differences materialize a lack warming hole presence configurations. All occur resolutions.