A Simplified Climate Model for Understanding Tropical Cyclones and Ocean
Heat Transport
Abstract
Tropical cyclones (TCs) are perhaps the most powerful example of air-sea
interaction. Although TC-induced energy exchange has been hypothesized
to be a signicant 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 conguration 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 congure 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 Pacic. By comparing ocean-only simulations with and without TCs in
the atmospheric forcing, we evaluate the signicance 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.