American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 350480 bytes)    Cited by

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, D13120, doi:10.1029/2006JD007368, 2007

Dependence of climate states of gray atmosphere on solar constant: From the runaway greenhouse to the snowball states

M. Ishiwatari

Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan


K. Nakajima

Faculty of Sciences, Kyushu University, Fukuoka, Japan


S. Takehiro

Research Institute for Mathematical Sciences, Kyoto University, Kyoto, Japan


Y.-Y. Hayashi

Graduate School of Sciences, Kobe University, Kobe, Japan


Abstract

Multiple equilibrium solutions of a gray atmosphere are investigated for various values of the solar constant. Two types of models are utilized in order to conduct a comparative study: a general circulation model with simplified physical processes (GCM) and a one-dimensional energy balance model (EBM). For intermediate values of solar constant, both of the models indicate the existence of multiple solutions that include the runaway greenhouse state in addition to the globally ice-covered state and the partially ice-covered state. In the GCM results, there is no partially ice-covered state with the ice line latitude lower than 22°. This indicates that the large ice cap instability discussed in previous EBM studies also occurs in GCM. Compared to the results of EBM, the ice line of the partially ice-covered state of GCM reaches lower latitudes. The appearance of the large ice cap instability in our GCM is impeded by condensation heating at the ice lines. The efficient latitudinal heat transport in the Hadley cell is considered to be a contributing factor to this delay in ice cap expansion.

Received 4 April 2006; accepted 2 May 2007; published 13 July 2007.

Keywords: atmospheric general circulation; runaway greenhouse state; snowball Earth.

Index Terms: 0429 Biogeosciences: Climate dynamics (1620); 3319 Atmospheric Processes: General circulation (1223); 0343 Atmospheric Composition and Structure: Planetary atmospheres (5210, 5405, 5704).

Read Full Article (file size: 350480 bytes)    Cited by

Citation: Ishiwatari, M., K. Nakajima, S. Takehiro, and Y.-Y. Hayashi (2007), Dependence of climate states of gray atmosphere on solar constant: From the runaway greenhouse to the snowball states, J. Geophys. Res., 112, D13120, doi:10.1029/2006JD007368.