Dynamical aspects of climate sensitivity

Dynamical aspects of climate feedback/sensitivity are investigated in climate change simulations with a common atmospheric general circulation model coupled to a full ocean model, which responds both dynamically and thermo‐dynamically, and to a mixed‐layer ocean component which responds only thermodynamically. Temperature responses differ with a warmer tropics and an El Niño‐like pattern in the full ocean case but not in the mixed‐layer case. There is also more warming in Arctic and less in Antarctic regions. The geographical patterns of radiative feedback also differ with positive feedback in the tropical Pacific in the full ocean case contrasting with negative feedback in the mixed‐layer case. Positive feedback in the tropical Pacific directly supports an El Niño‐like response to positive (and a La Niña‐like response to negative) radiative forcing. Radiative feedback depends implicitly on dynamical quantities and differences are a consequence of missing oceanic transport pathways in the mixed‐layer ocean.