Tropical Cyclone-Induced Energy Exchange in an Idealized, Coupled Atmosphere-Ocean Climate Model

Tropical cyclones (TCs) are perhaps the most powerful example of air-sea interaction. Although TC-induced energy exchange has been hypothesized to be a significant agent of ocean heat transport under past and current climates, the margin of uncertainty in both observation and TC-permitting conventional climate models confounds these evaluations. In this study, we introduce a novel approach using simpler climate models, where land geometry is represented by a single strip of pole-to-pole continent, known as the Ridge configuration in previous work. This idealized design is known to represent the large-scale features of atmosphere-ocean general circulation and energy transport, serving to facilitate the physical interpretation of TC-induced energy exchange in the ocean, and its potential role in ocean heat transport. Under the framework of the Community Earth System Model, we configure an idealized, fully coupled Ridge model using Community Atmosphere Model version 4 (CAM4) and Modular Ocean Model version 6 (MOM6) at low horizontal resolutions. After obtaining a quasi-equilibrium climate, we then use the climatological sea surface temperature for forcing a CAM4-only, decadal simulation at TC-permitting resolution. Preliminary results indicate that the formation of a warm pool on the western side of the bounded ocean basin creates a more favorable environment for TC genesis than the cooler eastern side, analogous to observed TC climatology in the Pacific. By comparing ocean-only simulations with and without TCs in the atmospheric forcing, we evaluate the significance of ocean heat transport attributable to TCs in the idealized atmosphere-ocean climate system. The insights gained through the process-based investigation of TC-induced air-sea interaction in this simpler model framework contribute to an improved understanding of the energetics of TCs, and their role in the climate system.