Kombayashi–Ingersoll limit

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In planetary science, the Kombayashi–Ingersoll limit represents the maximum solar flux a planet can handle without a runaway greenhouse effect setting in.[1][2][3]

For planets with temperature-dependent sources of greenhouse gases such as liquid water and optically thin atmospheres the outgoing longwave radiation curve (which indicates how fast energy can be radiated away by the planet) flattens at high temperatures, reaching a horizontal asymptote - the Kombayashi–Ingersoll limit itself. Since the equilibrium temperature is the intersection of this curve and a horizontal line representing solar flux, for fluxes above this point the planet heats up indefinitely.[4] Kasting estimated the limit for Earth to 320 Watts per square meter.[5]

The limit is relevant for estimating the inner edge of the circumstellar habitable zone. However, the limit also depends on the surface gravity of the planet, making heavy worlds somewhat more resistant to the runaway effect.[3]

References[edit]

  1. ^ Kombayashi, M. (1967). "Discrete equilibrium temperatures of a hypothetical planet with the atmosphere and the hydrosphere of one component-two phase system under constant solar radiation". J. Meteor. Soc. Japan 45: 137–138. 
  2. ^ Ingersoll, A. P. (1969). "The runaway greenhouse: A history of water on Venus". J. Atmos. Sci 26: 1191–1198. doi:10.1175/1520-0469(1969)026<1191:TRGAHO>2.0.CO;2. 
  3. ^ a b Raymond T. Pierrehumbert. Principles of Planetary Climate. Cambridge University Press. 2010
  4. ^ http://www.skepticalscience.com/print.php?r=262
  5. ^ Kasting, J. F. (1988). "Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus". Icarus 74: 472–494. doi:10.1016/0019-1035(88)90116-9.