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Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency

Abstract

A minimum atmospheric temperature, or tropopause, occurs at a pressure of around 0.1 bar in the atmospheres of Earth1, Titan2, Jupiter3, Saturn4, Uranus and Neptune4, despite great differences in atmospheric composition, gravity, internal heat and sunlight. In all of these bodies, the tropopause separates a stratosphere with a temperature profile that is controlled by the absorption of short-wave solar radiation, from a region below characterized by convection, weather and clouds5,6. However, it is not obvious why the tropopause occurs at the specific pressure near 0.1 bar. Here we use a simple, physically based model7 to demonstrate that, at atmospheric pressures lower than 0.1 bar, transparency to thermal radiation allows short-wave heating to dominate, creating a stratosphere. At higher pressures, atmospheres become opaque to thermal radiation, causing temperatures to increase with depth and convection to ensue. A common dependence of infrared opacity on pressure, arising from the shared physics of molecular absorption, sets the 0.1 bar tropopause. We reason that a tropopause at a pressure of approximately 0.1 bar is characteristic of many thick atmospheres, including exoplanets and exomoons in our galaxy and beyond. Judicious use of this rule could help constrain the atmospheric structure, and thus the surface environments and habitability, of exoplanets.

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Figure 1: Temperature–pressure profiles for worlds in the Solar System with thick atmospheres1,2,3,4,28.
Figure 2: Schematic diagram of thermal structure in a thick planetary atmosphere with a stratospheric inversion.
Figure 3: Tropopause grey infrared optical depth and pressure.

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References

  1. McClatchey, R. A., Fenn, R. W., Selby, J. E. A., Volz, F. E. & Garing, J. S. Optical Properties of the Atmosphere 3rd edn (Air Force Cambridge Research Labs, 1972).

    Google Scholar 

  2. Lindal, G. F. et al. The atmosphere of Titan—an analysis of the Voyager 1 radio occultation measurements. Icarus 53, 348–363 (1983).

    Article  Google Scholar 

  3. Moses, J. I. et al. Photochemistry and diffusion in Jupiter’s stratosphere: Constraints from ISO observations and comparisons with other giant planets. J. Geophys. Res. 110, E08001 (2005).

    Google Scholar 

  4. Lindal, G. F. The atmosphere of Neptune—an analysis of radio occultation data acquired with Voyager 2. Astron. J. 103, 967–982 (1992).

    Article  Google Scholar 

  5. Sanchez-Lavega, A. An Introduction to Planetary Atmospheres (CRC Press/Taylor & Francis, 2010).

    Book  Google Scholar 

  6. Goody, R. M. & Yung, Y. L. Atmospheric Radiation: Theoretical Basis (Oxford Univ. Press, 1989).

    Google Scholar 

  7. Robinson, T. D. & Catling, D. C. An analytic radiative–convective model for planetary atmospheres. Astrophys. J. 757, 104 (2012).

    Article  Google Scholar 

  8. Schneider, T. The tropopause and the thermal stratification in the extratropics of a dry atmosphere. J. Atmos. Sci. 61, 1317–1340 (2004).

    Article  Google Scholar 

  9. Haqq-Misra, J., Lee, S. & Frierson, D. M. W. Tropopause structure and the role of eddies. J. Atmos. Sci. 68, 2930–2944 (2011).

    Article  Google Scholar 

  10. Pollack, J. B. Temperature structure of nongray planetary atmospheres. Icarus 10, 301–313 (1969).

    Article  Google Scholar 

  11. McKay, C. P., Lorenz, R. D. & Lunine, J. I. Analytic solutions for the antigreenhouse effect: Titan and the early earth. Icarus 137, 56–61 (1999).

    Article  Google Scholar 

  12. Kondrat’ev, K. I. A. Radiation in the Atmosphere Vol. 12 (Academic, 1969).

    Google Scholar 

  13. Hanel, R. A., Conrath, B. J., Jennings, D. E. & Samuelson, R. E. Exploration of the Solar System by Infrared Remote Sensing (Cambridge Univ. Press, 2003).

    Book  Google Scholar 

  14. Seidel, D. J. & Randel, W. J. Variability and trends in the global tropopause estimated from radiosonde data. J. Geophys. Res. 111, D21101 (2006).

    Article  Google Scholar 

  15. Armstrong, B. H. Theory of the diffusivity factor for atmospheric radiation. J. Quant. Spectrosc. Rad. Transfer 8, 1577–1599 (1968).

    Article  Google Scholar 

  16. Rodgers, C. D. & Walshaw, C. D. Polynomial approximations to radiative functions. Q. J. R. Meteorol. Soc. 89, 422–423 (1963).

    Article  Google Scholar 

  17. Tellmann, S., Patzold, M., Hausler, B., Bird, M. K. & Tyler, G. L. Structure of the Venus neutral atmosphere as observed by the Radio Science experiment VeRa on Venus Express. J. Geophys. Res. 114, E00B36 (2009).

    Article  Google Scholar 

  18. Baker, N. L. & Leovy, C. B. Zonal winds near Venus cloud top level: A model study of the interaction between the zonal mean circulation and the semidiurnal tide. Icarus 69, 202–220 (1987).

    Article  Google Scholar 

  19. Mills, F. P., Esposito, L. W. & Yung, Y. L. in Exploring Venus as a Terrestrial Planet Geophysical Monograph Series (eds Esposito, L.W., Stofan, E. R. & Cravens, T. E.) 73–100 (American Geophysical Union, 2007).

    Book  Google Scholar 

  20. Kasting, J. F., Whitmire, D. P. & Reynolds, R. T. Habitable zones around main sequence stars. Icarus 101, 108–128 (1993).

    Article  Google Scholar 

  21. Yung, Y. L. & DeMore, W. B. Photochemistry of Planetary Atmospheres (Oxford Univ. Press, 1999).

    Google Scholar 

  22. Madhusudhan, N. & Seager, S. A temperature and abundance retrieval method for exoplanet atmospheres. Astrophys. J. 707, 24–39 (2009).

    Article  Google Scholar 

  23. Deming, D. et al. Discovery and characterization of transiting super earths using an all-sky transit survey and follow-up by the James Webb space telescope. Publ. Astron. Soc. Pacif. 121, 952–967 (2009).

    Article  Google Scholar 

  24. Beichman, C. A., Woolf, N. J. & Lindensmith, C. A. The Terrestrial Planet Finder (TPF): A NASA Origins Program to Search for Habitable Planets (NASA Jet Propulsion Laboratory, 1999).

    Google Scholar 

  25. Von Paris, P., Hedelt, P., Selsis, F., Schreier, F. & Trautmann, T. Characterization of potentially habitable planets: Retrieval of atmospheric and planetary properties from emission spectra. Astron. Astrophys. 551, A120 (2013).

    Article  Google Scholar 

  26. Des Marais, D. J. et al. Remote sensing of planetary properties and biosignatures on extrasolar terrestrial planets. Astrobiology 2, 153–181 (2002).

    Article  Google Scholar 

  27. Han, T. T., Ping, J. S. & Zhang, S. J. Global features and trends of the tropopause derived from GPS/CHAMP RO data. Sci. China 54, 365–374 (2011).

    Article  Google Scholar 

  28. Moroz, V. I. & Zasova, L. V. VIRA-2: A review of inputs for updating the Venus International Reference Atmosphere. Adv. Space Res. 19, 1191–1201 (1997).

    Article  Google Scholar 

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Acknowledgements

This work was performed as part of the NASA Astrobiology Institute’s Virtual Planetary Laboratory, supported by the National Aeronautics and Space Administration through the NASA Astrobiology Institute under solicitation No. NNH05ZDA001C. T.D.R. gratefully acknowledges support from an appointment to the NASA Postdoctoral Program at NASA Ames Research Center, administered by Oak Ridge Associated Universities. D.C.C. was also supported by NASA Exobiology/Astrobiology grant NNX10AQ90G. The authors thank the late C. Leovy for discussions in which he was supportive of pursuing the idea that a 0.1 bar tropopause constitutes an emergent law.

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T.D.R. and D.C.C. made equally important contributions to the project and co-wrote the paper. T.D.R. generated the model outputs.

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Correspondence to T. D. Robinson.

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The authors declare no competing financial interests.

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Robinson, T., Catling, D. Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency. Nature Geosci 7, 12–15 (2014). https://doi.org/10.1038/ngeo2020

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