Sack Lunch Seminar (SLS)

Recent observations show that the Southern Ocean is dominating anthropogenic ocean heat uptake. Southern Ocean heat uptake is large because the strong northward transport of the heat content anomaly limits warming of the sea surface temperature in the uptake region. Using results from eddy-rich global climate simulations, I will discuss the processes controlling the northward heat transport away from the uptake region and the convergence of the heat content anomaly in the midlatitude Southern Ocean. Heat budget analyses reveal that different processes dominate to the north and south of the main convergence region. The heat transport northward from the high-latitude uptake region is driven primarily by passive advection of the heat content anomaly by the existing time mean circulation, with a smaller contribution from enhanced upwelling. The heat anomaly builds up in the midlatitudes due to a convergent Ekman transport anomaly, combined with limited heat transport further northward into the mode waters. To the north of the peak convergence region, eddy processes drive the warming and account for nearly 80% of the northward heat transport anomaly.