Ocean Heat Uptake and Dynamic Sea Level: Past and Future Uncertainty

The ocean absorbs a significant portion of the anthropogenic heat released in the climate system, leading to an increase in global mean sea level. Observed and projected regional patterns of heat uptake in mid- and high-latitudes are controlled in part by changes in ocean circulation. I will introduce a new reconstruction of ocean heat content starting from 1871, and together with models and direct measurements present evidence that in the mid-latitude North Atlantic: 1) Up to half of the thermosteric sea level trend since 1955 is due to ocean circulation changes; 2) the uncertainty in dynamic sea level projections can be explained by the ocean circulation response to uncertain air-sea fluxes (rather than from ocean model uncertainty).