Enhanced upper ocean warming projected by the eddy-resolving Community Earth System Model

Here we investigate vertical structure changes in globally averaged ocean heat content (OHC) in high- (HR) and low-resolution (LR) future climate simulations with the Community Earth System Model (CESM). Compared with observation-based estimates, the simulated OHC anomalies in the upper 700 and 2,000 m during 1960-2020 are more realistic in CESM-HR than -LR.

Under RCP8.5 scenario, the net surface heat into the ocean is very similar in CESM-HR and -LR. However, CESM-HR has a larger increase in OHC in the upper 250 m compared to CESM-LR, but a smaller increase below 250 m. This difference can be traced to differences in eddy-induced vertical heat transport between CESM-HR and -LR in the historical period.