Interannual Variability of the South Atlantic Ocean Heat Content in a High-Resolution Versus a Low-Resolution General Circulation Model Geophysical Research Letters

High- and low-resolution coupled climate model simulations are analyzed to investigate the impact of model resolution on South Atlantic Ocean Heat Content (OHC) variability at interannual time scale and the associated physical mechanisms. In both models, ocean heat transport convergence is the main driver of OHC variability on interannual time scales. However, the origin of the meridional heat transport (MHT) convergence anomalies differs in the two models. In the high-resolution model, OHC variability is dominated by MHT from the south. This is in contrast to the low-resolution model, where OHC variability is largely controlled by MHT from the north. In the low-resolution simulation, both the Ekman and geostrophic transports contribute to the OHC variability, whereas in the high-resolution model, the geostrophic transport dominates. These differences highlight the importance of model resolution to appropriately represent ocean dynamics in the South Atlantic Ocean and associated impacts on regional and global climate. Grant no. NA15OAR4320064