Classification and prevalence of transitional climate states

Determine whether the partially melted, intermediate climate behavior identified between Hot and Eyeball regimes warrants recognition as a distinct climatic classification, and quantify the statistical likelihood that tidally locked exoplanets occupy such transitional states as a function of stellar flux.

Background

The simulations identify three principal climate regimes—Snowball, Eyeball, and Hot—and additionally find three planets with intermediate properties, including partially ice-free night hemispheres. These planets are described as occupying a Transitional regime between completely ice-free Hot states and Eyeball states.

The authors leave unresolved whether this intermediate behavior represents a sufficiently distinct and physically meaningful class. Resolving the issue requires relating the extent of the transition to stellar flux and determining how frequently such states should occur among tidally locked exoplanets.