Understanding the Spatial Patterns of Ocean Heat Uptake and Storage Under Global Warming

Sea-surface heat uptake and ocean heat storage must match one another at the global scale. However, the spatial patterns of surface heat uptake and heat storage are distinct from one another, implying that horizontal heat transport plays an important role. Here we summarize recent efforts to identify the dynamics behind these distinct patterns. We show that in the Southern Hemisphere, multidecadal patterns of heat uptake and storage are largely a consequence of the background ocean circulation, with wind-driven changes in circulation playing a secondary role. In the Northern Hemisphere, changes in the Atlantic Meridional Overturning Circulation and the subpolar gyre play a dominant role. In the high-latitudes of both hemispheres, the pattern of sea-surface heat uptake under global warming is set by the regional ocean circulations that act remove heat from the upper ocean (via transport horizontally and to depth). Thus, while global ocean heat uptake can be understood to curb the pace of global warming by removing heat from the sea surface, it is regional ocean dynamics that regulate the locations at and efficiency by which this occurs.