Enhanced Ocean Heat Uptake by Mesoscale Eddies in a Community Earth System Model

Abstract The ocean acts as a major buffer of global warming by absorbing approximately 90% of heat surplus over the past half century. An in‐depth knowledge of dynamical processes underpinning the ocean heat uptake (OHU) is crucial for accurately projecting anthropogenic climate changes. Mesoscale eddies contribute importantly to heat transport in the ocean, but their effects on the OHU remain poorly understood. Based on a high‐resolution climate simulation from a community earth system model, we find that mesoscale eddy vertical heat transport (EVHT), upward at the climatological mean state, is projected to weaken under global warming. This corresponds to an anomalous downward heat transport, facilitating the ocean absorption of heat surplus from the atmosphere and its storage in the deep ocean. Numerical sensitivity experiments suggest that the anthropogenic EVHT change could contribute to about 20% of the OHU by the end of the 21st century under a high carbon emission scenario.