Revision of "Dependence of Climate States of Gray Atmosphere on Solar Constant : From the Runaway Greenhouse to the Snowball States" by Ishiwatari et al. (2007)

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Ishiwatari, M., Nakajima, K., Takehiro, S., Hayashi, Y. Y., Kawai, Y., Takahashi, Y. O.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union
• Subjects: climate regime diagram; energy balance model; general circulation model; gray atmosphere; the globally ice-covered state; the runaway greenhouse state; 451; Ice cap
• Online Access: http://hdl.handle.net/2115/82254; https://doi.org/10.1029/2019JD031761

Ishiwatari et al. (2007) (https://doi.org/10.1029/2006JD007368) investigated multiple equilibrium solutions of a gray atmosphere for various values of solar constant, utilizing two types of models, namely, a one-dimensional energy balance model and a general circulation model (GCM) with simplified physical processes, both of which permit existence of the runaway greenhouse state. The study was retracted, since there was a bug in their GCM that affected quantitative aspects of the study. Here, we revise the study with re-performing all of the GCM experiments using an appropriately corrected model. The results of re-experiments show that the main features of the climate regime diagram drawn in the solar constant - ice line latitude plane are mostly unchanged, except that the ice-free equilibrium state, which existed in Ishiwatari et al. (2007) (https://doi.org/10.1029/2006JD007368) now disappears. It is confirmed that there are the partially ice-covered state, the globally ice-covered state, and the runaway greenhouse state. These three states coexist for intermediate values of solar constant. The existence of the large ice cap instability is also confirmed, although the critical latitude of the partially ice-covered state extends equatorward. Also same as before, the small ice cap instability does not seem to appear.