Abstract
There are records of past Earth climates that were ice-free all the way
to the poles (Barron 1983), which can be described as “hothouse”
climates. These hothouse climates can be contrasted with an
“all-tropics” planet, where the tropics are defined by the atmospheric
dynamics, i.e. the Hadley Cell extent (Faulk et al. 2017). This
classification is thus primarily dependent on a planet’s rotation,
rather than its ice-free extent or surface temperatures. We investigate
the parameter space between Earth and an all-tropics world using the
open-source GCM Isca, developed by Vallis et al (2018). We take an Earth
analog and perform a parameter sweep in two dimensions: global reservoir
depth (10m, 1m, 1cm) and rotation period (8 days, 4 days, 1 day). The
sweep will allow us to explore the effects of surface liquid
coverage and large-scale atmospheric circulation on an Earth-like
climate. To better represent the distribution of surface water, we
utilize the surface hydrology scheme developed by Faulk et al. (2020)
for the Titan Atmosphere Model. In this presentation we provide a status
report and analysis of initial findings.