353 / 2024-09-14 19:29:21
Impact of Horizontal Resolution on Simulating Eddy-induced Meridional Heat Transport in the Southeast Indian Ocean
Baroclinic Instability,Phase relation,Eddy-induced meridional heat transport,Mesoscale eddies
Session 46 - Oceanic Mesoscale and Submesoscale Processes: Characteristics, Dynamics & Parameterizations
Abstract Accepted
The eddy-induced meridional heat transport (EMHT) in the Southeast Indian Ocean (SEIO) plays a crucial role in regional air-sea interactions and climate changes, but it is commonly underestimated in state-of-art models. This study uses three experiments of the Regional Ocean Modeling System with varying horizontal resolutions to assess their impact on simulating EMHT in the SEIO. The results show that an increase in horizontal resolution enhances the simulated EMHT with a stronger seasonal cycle. The higher horizontal resolution experiments also show improvements in the association and phase difference between high-frequency temperature and meridional velocity, both of which are the definition of EMHT. According to turbulent diffusion theory, the magnitude of EMHT is directly correlated with eddy kinetic energy (EKE). Across all experiments, EKE closely aligns with EMHT in terms of vertical and temporal variations as well as spatial patterns. Diagnostic analysis suggests that the improvement in EKE is primarily attributed to the increased baroclinic instability simulated in experiments with higher horizontal resolutions, associated with the simulation of more potent and numerous mesoscale eddies. Furthermore, the seasonal variation in EMHT is strongly tied to the number of mesoscale eddies in each model experiment. These results emphasize the significance of accurately simulating mesoscale eddies, particularly with increasing horizontal resolution, in order to improve the simulation of EMHT in the SEIO.