Tropical Cyclone-Ocean Interactions in a Fully-Coupled High Resolution Earth System Model

Abstract:

Tropical cyclones (TCs) actively contribute to Earth's climate, but TC-climate interactions are largely unexplored in fully-coupled models. Here we analyze the upper-ocean response to TCs using a high resolution Earth system model, in which a 0.5° atmosphere is coupled to an ocean with two different horizontal resolutions: 1° and 0.1°. We use these runs to examine the potential sensitivity of the TC-induced model responses to ocean grid resolution, and we explore key climate connections including TC-induced cool wakes and recovery, latent heat budgets, and basin-scale ocean heat convergence. We find that sea surface cooling and basin-scale aggregated ocean heat convergence are relatively insensitive to the horizontal ocean grid resolutions considered here, but we find key differences in the post-storm restratification processes related to mesoscale oceanic eddies. We estimate the annual basin-scale TC-induced latent heat fluxes for both model simulations to be roughly 45% of the total TC-induced ocean heat loss from the upper ocean. Results suggest that coupled modeling approaches capable of capturing ocean-atmosphere feedbacks are important for developing a complete understanding of the relationship between TCs and climate.