Transition from eyeball to snowball driven by sea-ice drift on tidally locked terrestrial planets

Article metrics


Tidally locked terrestrial planets around low-mass stars are the prime targets for future atmospheric characterizations of potentially habitable systems1, especially the three nearby ones—Proxima b (ref. 2), TRAPPIST-1e (ref. 3) and LHS 1140b (ref. 4). Previous studies suggest that if these planets had surface oceans they would be in an eyeball-like climate state5,6,7,8,9,10: ice free in the vicinity of the substellar point and ice covered in the remaining regions. However, an important component of the climate system—sea-ice dynamics—has not been fully considered in previous studies. A fundamental question is whether an open ocean is stable against a globally ice-covered snowball state. Here we show that sea-ice drift cools the ocean’s surface when the ice flows towards the warmer substellar region and melts through absorbing heat from the ocean and the overlying air. As a result, the open ocean shrinks and can even disappear when atmospheric greenhouse gases are not much more abundant than on Earth, turning the planet into a snowball state. This occurs for both synchronous rotation and spin–orbit resonances (such as 3:2). These results suggest that sea-ice drift strongly reduces the open-ocean area and can significantly impact the habitability of tidally locked planets.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Sea-ice concentrations in synchronous rotation orbits.
Fig. 2: Physical mechanisms for the effect of sea-ice drift.
Fig. 3: Effects of continents on the sea-ice concentrations.
Fig. 4: Snapshots of ice concentrations in 3:2 resonance orbits.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.

Code availability

The source codes of the model CCSM3 can be downloaded from, and changes of the model are available from the corresponding author.


  1. 1.

    Morley, C. V., Kreidberg, L., Rustamkulov, Z., Robinson, T. & Fortney, J. J. Observing the atmospheres of known temperate earth-sized planets with JWST. Astrophys. J. 850, 121 (2017).

  2. 2.

    Anglada-Escude, G. et al. A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature 536, 437–440 (2016).

  3. 3.

    Gillon, M. et al. Seven temperate terrestrial planets around the nearby ultra-cool dwarf star TRAPPIST1. Nature 542, 456–460 (2017).

  4. 4.

    Dittmann, J. A. et al. A temperate rocky super-Earth transiting a nearby cool star. Nature 544, 333–336 (2017).

  5. 5.

    Pierrehumbert, R. T. A palette of climates for Gliese 581g. Astrophys. J. Lett. 726, L8–L12 (2011).

  6. 6.

    Turbet, M. et al. The habitability of Proxima Centauri b-II. Possible climates and observability. Astron. Astrophys. 596, A112 (2016).

  7. 7.

    Wolf, E. T. Assessing the habitability of the TRAPPIST-1 system using a 3D climate model. Astrophys. J. Lett. 839, L1 (2017).

  8. 8.

    Boutle, I. A. et al. Exploring the climate of Proxima B with the Met Office Unified Model. Astron. Astrophys. 601, A120 (2017).

  9. 9.

    Turbet, M. et al. Modeling climate diversity, tidal dynamics and the fate of volatiles on TRAPPIST-1 planets. Astron. Astrophys. 612, 1–22 (2018).

  10. 10.

    Del Genio, A. D. et al. Habitable climate scenarios for Proxima Centauri b with a dynamic ocean. Astrobiology 19, 99–125 (2019).

  11. 11.

    Hibler, W. D. III A dynamic thermodynamic sea ice model. J. Phys. Oceanogr. 9, 815–846 (1979).

  12. 12.

    Lepparanta, M. The Drift of Sea Ice (Springer, 2011).

  13. 13.

    Hoffman, P. F., Kaufman, A. J., Halverson, G. P. & Schrag, D. P. A Neoproterozoic snowball Earth. Science 281, 1342–1346 (1998).

  14. 14.

    Pierrehumbert, R. T., Abbot, D. S., Voigt, A. & Koll, D. Climate of the Neoproterozoic. Annu. Rev. Earth Planet. Sci. 39, 417–460 (2011).

  15. 15.

    Voigt, A. & Abbot, D. S. Sea-ice dynamics strongly promote Snowball Earth initiation and destabilize tropical sea-ice margins. Clim. Past 8, 2079–2092 (2012).

  16. 16.

    Lewis, J. P., Weaver, A. J. & Eby, M. Snowball versus slushball Earth: dynamic versus nondynamic sea ice? J. Geophys. Res. 112, C11014 (2007).

  17. 17.

    Hu, Y. & Yang, J. Role of ocean heat transport in climates of tidally locked exoplanets around M dwarf stars. Proc. Natl Acad. Sci. USA 111, 629–634 (2014).

  18. 18.

    Showman, A. P., Wordsworth, R. D., Merlis, T. M. & Kaspi, Y. Atmospheric Circulation of Terrestrial Exoplanets (Univ. Arizona Press, 2013).

  19. 19.

    Haqq-Misra, J. et al. Demarcating circulation regimes of synchronously rotating terrestrial planets near the inner edge of the habitable zone. Astrophys. J. 852, 1 (2017).

  20. 20.

    Yang, J., Liu, Y., Hu, Y. & Abbot, D. S. Water trapping on tidally locked terrestrial planets requires special conditions. Astrophys. J. Lett. 796, L22 (2014).

  21. 21.

    Shields, A. L. et al. The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets. Astrobiology 13, 715–739 (2013).

  22. 22.

    Yang, J., Cowan, N. B. & Abbot, D. S. Stabilizing cloud feedback dramatically expands the habitable zone of tidally locked planets. Astrophys. J. Lett. 771, L45 (2013).

  23. 23.

    Lindzen, R. S. & Nigam, S. On the role of sea surface temperature gradients in forcing low-level winds and convergence in the tropics. J. Atmos. Sci. 44, 2418–2436 (1987).

  24. 24.

    Salameh, J., Popp, M. & Marotzke, J. The role of sea-ice albedo in the climate of slowly rotating aquaplanets. Clim. Dyn. 50, 2395–2410 (2018).

  25. 25.

    Kaspi, Y. & Showman, A. P. Atmospheric dynamics of terrestrial exoplanets over a wide range of orbital and atmospheric parameters. Astrophys. J. 804, 60 (2015).

  26. 26.

    Goldblatt, C. Comment on “Long-term climate forcing by atmospheric oxygen concentrations”. Science 353, 132 (2016).

  27. 27.

    Menou, K. Climate stability of habitable Earth-like planets. Earth Planet. Sci. Lett. 429, 20–25 (2015).

  28. 28.

    Checlair, J., Menou, K. & Abbot, D. S. No snowball on habitable tidally locked planets. Astrophys. J. 845, 132 (2017).

  29. 29.

    de Wit, J. et al. Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1. Nat. Astron. 2, 214–219 (2018).

  30. 30.

    Tziperman, E. et al. Continental constriction and oceanic ice-cover thickness in a Snowball-Earth scenario. J. Geophys. Res. 117, C05016 (2012).

  31. 31.

    Collins, W. D. et al. The Community Climate System Model version 3 (CCSM3). J. Clim. 19, 2122–2143 (2006).

  32. 32.

    Rosenbloom, N., Shields, C. A., Brady, E., Yeager, S. & Levis, S. Using CCSM3 for Paleoclimate Applications Technical Note NCAR/TN-483 + STR:81 (NCAR, 2011).

  33. 33.

    Yang, J., Abbot, D. S., Koll, D. B., Hu, Y. & Showman, A. P. Ocean dynamics and the inner edge of the habitable zone for tidally locked terrestrial planets. Astrophys. J. 871, 1–17 (2019).

  34. 34.

    Yang, J. et al. Abrupt climate transition of icy worlds from snowball to moist or runaway greenhouse. Nat. Geosci. 10, 556–560 (2017).

  35. 35.

    Liu, Y., Peltier, W. R., Yang, J., Vettoretti, G. & Wang, Y. Strong effects of tropical ice sheet coverage and thickness on the hard snowball earth bifurcation point. Clim. Dyn. 48, 3459–3474 (2016).

  36. 36.

    Collins, W. D. et al. Description of the NCAR Community Atmosphere Model (CAM 3.0) Technical Note NCAR/TN-4641STR; 214 (NCAR, 2004).

  37. 37.

    Smith, R., & Gent, P. Reference Manual for the Parallel Ocean Program (POP): Ocean Component of the Community Climate System Model (CCSM2.0 and 3.0) Technical Note LAUR-02-2484; 76 (LANL and NCAR, 2004).

  38. 38.

    Oleson, K. W. et al. Technical Description of the Community Land Model (CLM) Technical Note NCAR/TN-4611STR; 174 (NCAR, 2004).

  39. 39.

    Briegleb, B. P. et al. Scientific Description of the Sea Ice Component in the Community Climate System Model, Version 3. Technical Note NCAR/TN-4631STR; 78 (NCAR, 2004).

  40. 40.

    Gent, P. R. & McWilliams, J. C. Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr. 20, 150–155 (1990).

  41. 41.

    Bin, J. Y., Tian, F. & Liu, W. New inner boundaries of the habitable zones around M dwarfs. Earth Planet. Sci. Lett. 492, 121–129 (2018).

  42. 42.

    Bolmont, E. et al. Water loss from terrestrial planets orbiting ultra cool dwarfs: implications for the planets of TRAPPIST-1. Mon. Not. R. Astron. Soc. 464, 3728–3741 (2017).

  43. 43.

    Carone, L., Keppens, R. & Decin, L. Connecting the dots—II. Phase changes in the climate dynamics of tidally locked terrestrial exoplanets. Mon. Not. R. Astron. Soc. 453, 2412–2437 (2015).

  44. 44.

    Chemke, R. & Kaspi, Y. Dynamics of massive atmospheres. Astrophys. J. 845, 1–12 (2017).

  45. 45.

    Edson, A., Lee, S., Bannon, P., Kasting, J. F. & Pollard, D. Atmospheric circulations of terrestrial planets orbiting low-mass stars. Icarus 212, 1–13 (2011).

  46. 46.

    Fujii, Y., Del Genio, A. D. & Amundsen, D. S. NIR-driven moist upper atmospheres of synchronously rotating temperate terrestrial exoplanets. Astrophys. J. 848, 100 (2017).

  47. 47.

    Heng, K. & Vogt, S. S. Gliese 581g as a scaled-up version of earth: atmospheric circulation simulations. Mon. Not. R. Astron. Soc. 415, 2145–2157 (2011).

  48. 48.

    Joshi, M. M. & Haberle, R. M. Suppression of the water ice and snow albedo feedback on planets orbiting red dwarf stars and the subsequent widening of the habitable zone. Astrobiology 12, 3–8 (2012).

  49. 49.

    Koll, D. B. & Abbot, D. S. Temperature structure and atmospheric circulation of dry, tidally locked rocky exoplanets. Astrophys. J. 825, 99 (2016).

  50. 50.

    Komacek, T. D. & Abbot, D. S. The atmospheric circulation and climate of terrestrial planets orbiting Sun-like and M-dwarf stars over a broad range of planetary parameters. Astrophys. J. 871, 1–20 (2019).

  51. 51.

    Kopparapu, R. K. et al. The inner edge of the habitable zone for synchronously rotating planets around low-mass stars using general circulation models. Astrophys. J. 819, 84 (2016).

  52. 52.

    Kopparapu, R. K. et al. Habitable moist atmospheres on terrestrial planets near the inner edge of the habitable zone around M dwarfs. Astrophys. J. 845, 1 (2017).

  53. 53.

    Leconte, J. et al. 3D climate modeling of close-in land planets: circulation patterns, climate moist bistability and habitability. Astron. Astrophys. 554, A19 (2013).

  54. 54.

    Merlis, T. M. & Schneider, T. Atmospheric dynamics of Earth-like tidally locked aqua-planets. J. Adv. Model Earth Syst. 2, 13 (2010).

  55. 55.

    Menou, K. Water-trapped worlds. Astrophys. J. 774, 51 (2013).

  56. 56.

    Noda, S. et al. The circulation pattern and day-night heat transport in the atmosphere of a synchronously rotating aquaplanet: dependence on planetary rotation rate. Icarus 282, 1–18 (2017).

  57. 57.

    Shields, A. L. et al. Spectrum-driven planetary deglaciation due to increases in stellar luminosity. Astrophys. J. 785, L9 (2014).

  58. 58.

    Wang, Y. et al. Effects of obliquity on the habitability of exoplanets around M dwarfs. Astrophys. J. 823, L20 (2016).

  59. 59.

    Wordsworth, R. et al. Gliese 581d is the first discovered terrestrial-mass exoplanet in the habitable zone. Astrophys. J. Lett. 733, L48 (2011).

  60. 60.

    Wordsworth, R. Atmospheric heat redistribution and collapse on tidally locked rocky planets. Astrophys. J. 806, 180 (2015).

  61. 61.

    Wolf, E. T., Shields, A. L., Kopparapu, R. K., Haqq-Misra, J. & Toon, O. B. Constraints on climate and habitability for Earth-like exoplanets determined from a general circulation model. Astrophys. J. 837, 2 (2017).

  62. 62.

    Zhang, X. & Showman, A. P. Effects of bulk composition on the atmospheric dynamics on close-in exoplanets. Astrophys. J. 836, 73 (2017).

  63. 63.

    Way, M. J., Del Genio, A. D., Kelley, M., Aleinov, I. & Clune T. Exploring the inner edge of the habitable zone with coupled oceans. Preprint at (2015).

  64. 64.

    Cullum, J., Stevens, D. & Joshi, M. The importance of planetary rotation period for ocean heat transport. Astrobiology 14, 645–650 (2014).

  65. 65.

    Cullum, J., Stevens, D. P. & Joshi, M. M. Importance of ocean salinity for climate and habitability. Proc. Natl Acad. Sci. USA 113, 4278–4283 (2016).

  66. 66.

    Kimura, N. Sea ice motion in response to surface wind and ocean current in the Southern Ocean. J. Meteor. Soc. Jpn 82, 1223–1231 (2004).

  67. 67.

    Thorndike, A. S. & Colony, R. Sea ice motion in response to geostrophic winds. J. Geophys. Res. 87, 5845–5852 (1982).

  68. 68.

    Pollard, D. & Kasting, J. F. Snowball Earth: a thin-ice solution with flowing sea glaciers. J. Geophys. Res. 110, C07010 (2005).

  69. 69.

    Shields, A. L. & Carns, R. C. Hydrohalite salt-albedo feedback could cool M-dwarf planets. Astrophys. J. 867, 11 (2018).

  70. 70.

    Allard, F., Homeier, D. & Freytag, B. Models of very-low-mass stars, brown dwarfs, and exoplanets. Philos. Trans. R. Soc. A 370, 2765–2777 (2012).

  71. 71.

    Barnes, R., Raymond, S. N., Jackson, B. & Greenberg, R. Tides and the evolution of planetary habitability. Astrobiology 8, 557–568 (2008).

  72. 72.

    Leconte, J., Wu, H., Menou, K. & Murray, N. Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars. Science 347, 632–635 (2015).

  73. 73.

    Delrez, L. et al. Early 2017 observations of TRAPPIST-1 with Spitzer. Mon. Not. R. Astron. Soc. 475, 3577–3597 (2018).

  74. 74.

    Kane, S. R. The impact of stellar distances on habitable zone planets. Astrophys. J. Lett. 861, L21 (2016).

  75. 75.

    Grimm, S. L. et al. The nature of the TRAPPIST-1 exoplanets. Astron. Astrophys. 613, A68 (2018).

  76. 76.

    Ribas, I. et al. The habitability of Proxima Centauri b. I. Irradiation, rotation and volatile inventory from formation to the present. Astron. Astrophys. 596, A111 (2016).

  77. 77.

    Dong, C., Lingam, M., Ma, Y. & Cohen, C. Is Proxima Centauri b habitable? A study of atmospheric loss. Astrophys. J. Lett. 837, L26 (2017).

  78. 78.

    Pierrehumbert, R. T. Principles of Planetary Climate (Cambridge Univ. Press, 2010).

  79. 79.

    Donohoe, A. & Battisti, D. S. Atmospheric and surface contributions to planetary albedo. J. Clim. 24, 4402–4418 (2011).

  80. 80.

    Vallis, G. K. Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-Scale Circulation 745 (Cambridge Univ. Press, 2006).

  81. 81.

    Smith, R. et al. The Parallel Ocean Program (POP) Reference Manual: Ocean Component of the Community Climate System Model (CCSM) and Community Earth System Model (CESM) Technical Note LAUR-10-01853; 141 (LANL, 2010).

  82. 82.

    Haqq-Misra, J., Kopparapu, R. K., Batalha, N. E., Harman, C. E. & Kasing, J. F. Limit cycles can reduce the width of the habitable zone. Astrophys. J. 827, 120 (2016).

  83. 83.

    Abbot, D. S. Analytical investigation of the decrease in the size of the habitable zone due to a limited CO2 outgassing rate. Astrophys. J. 827, 2 (2016).

  84. 84.

    Kadoya, S. & Tajika, E. Conditions for oceans on earth-like planets orbiting within the habitable zone: importance of volcanic CO2 degassing. Astrophys. J. 790, 2 (2014).

  85. 85.

    Abbot, D. S., Bloch-Johnson, J., Checlair, J. & Farahat, N. X. Decrease in hysteresis of planetary climate for planets with long solar days. Astrophys. J. 854, 3 (2018).

Download references


We are grateful to F. Ding, T. J. Fauchez, Y. Liu and J. Lin for fruitful discussions, to Y. Hu and Y. Ashkenazy for their great help in improving the manuscript and to Y. Wang for his help in modifying source codes of the model. J.Y. acknowledges support from the National Natural Science Foundation of China (NSFC) grants 41861124002, 41675071, 41606060 and 41761144072.

Author information

J.Y. formulated the problem, designed the experiments, analysed the data, drew the figures, and wrote the manuscript. J.Y. and W.J. performed the numerical experiments. All authors contributed to data analyses.

Correspondence to Jun Yang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Astronomy thanks Dorian Abbot and Jacob Haqq-Misra for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yang, J., Ji, W. & Zeng, Y. Transition from eyeball to snowball driven by sea-ice drift on tidally locked terrestrial planets. Nat Astron (2019) doi:10.1038/s41550-019-0883-z

Download citation