1932

Abstract

Tide-locked planets are planets in which tidal stresses from the host star have spun down the planet's rotation to the point where its length of sidereal day equals its length of year. In a nearly circular orbit, such planets have a permanent dayside and a permanent nightside, leading to extreme heating contrasts. In this article, the atmospheric circulations forced by this heating contrast are explored, with a focus on terrestrial planets; here, “terrestrial” refers to planets with a condensed solid or liquid surface at which most of the incident stellar radiation is absorbed and does not imply habitability in the Earthlike sense. The census of exoplanets contains many terrestrial planets that are very likely to be tide locked, including extremely hot close-orbit planets around Sunlike stars and habitable zone (and hotter) planets around lower-mass stars. The circulations are discussed in terms of fluid dynamical concepts arising from study of the Earth's tropics, supplemented by general circulation model simulations. Even in the relatively simple context of dry (noncondensing) dynamics, there are a number of important unresolved issues that require further study.

Loading

Article metrics loading...

/content/journals/10.1146/annurev-fluid-010518-040516
2019-01-05
2024-06-18
Loading full text...

Full text loading...

/deliver/fulltext/fluid/51/1/annurev-fluid-010518-040516.html?itemId=/content/journals/10.1146/annurev-fluid-010518-040516&mimeType=html&fmt=ahah

Literature Cited

  1. Barnes R 2017. Tidal locking of habitable exoplanets. Celest. Mech. Dyn. Astron. 129:4509–36
    [Google Scholar]
  2. Charbonneau D, Berta ZK, Irwin J, Burke CJ, Nutzman P et al. 2009. A super-Earth transiting a nearby low-mass star. Nature 462:7275891–94
    [Google Scholar]
  3. Charney JG 1963. A note on large-scale motions in the tropics. J. Atmos. Sci. 20:6607–9
    [Google Scholar]
  4. Charney JG 1975. Dynamics of deserts and drought in the Sahel. Q. J. R. Meteorol. Soc. 101:428193–202
    [Google Scholar]
  5. Cowan NB, Agol E 2011. The statistics of albedo and heat recirculation on hot exoplanets. Astrophys. J. 729:154
    [Google Scholar]
  6. Demory BO, Gillon M, de Wit J, Madhusudhan N, Bolmont E et al. 2016. A map of the large day–night temperature gradient of a super-Earth exoplanet. Nature 532:7598207–9
    [Google Scholar]
  7. Gierasch PJ 1975. Meridional circulation and the maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 32:61038–44
    [Google Scholar]
  8. Gill A 1980. Some simple solutions for heat-induced tropical circulation. Q. J. R. Meteorol. Soc. 106:449447–62
    [Google Scholar]
  9. Goldreich P, Soter S 1966. Q in the solar system. Icarus 5:1–6375–89
    [Google Scholar]
  10. Hammond M, Pierrehumbert RT 2017. Linking the climate and thermal phase curve of 55 Cancri e. Astrophys. J. 849:2152
    [Google Scholar]
  11. Held IM, Hou AY 1980. Nonlinear axially symmetric circulations in a nearly inviscid atmosphere. J. Atmos. Sci. 37:3515–33
    [Google Scholar]
  12. Heng K, Showman AP 2015. Atmospheric dynamics of hot exoplanets. Annu. Rev. Earth Planet. Sci. 43:1509–40
    [Google Scholar]
  13. Joshi M 2003. Climate model studies of synchronously rotating planets. Astrobiology 3:2415–27
    [Google Scholar]
  14. Knutson HA, Charbonneau D, Allen LE, Fortney JJ, Agol E et al. 2007. A map of the day–night contrast of the extrasolar planet HD 189733b. Nature 447:7141183–86
    [Google Scholar]
  15. Koll DDB, Abbot DS 2016. Temperature structure and atmospheric circulation of dry, tidally locked rocky exoplanets. Astrophys. J. 825:299
    [Google Scholar]
  16. Komacek TD, Showman AP 2016. Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. Astrophys. J. 821:116
    [Google Scholar]
  17. Matsuno T 1966. Quasi-geostrophic motions in the equatorial area. J. Meteorol. Soc. Jpn. Ser. II 44:125–43
    [Google Scholar]
  18. Merlis TM, Schneider T 2010. Atmospheric dynamics of Earth-like tidally locked aquaplanets. J. Adv. Model. Earth Syst. 2:413
    [Google Scholar]
  19. Mitchell JL, Lora JM 2016. The climate of Titan. Annu. Rev. Earth Planet. Sci. 44:353–80
    [Google Scholar]
  20. Mitchell JL, Vallis GK 2010. The transition to superrotation in terrestrial atmospheres. J. Geophys. Res. E 115:E12008
    [Google Scholar]
  21. Pierrehumbert RT 1995. Thermostats, radiator fins, and the local runaway greenhouse. J. Atmos. Sci. 52:101784–806
    [Google Scholar]
  22. Pierrehumbert RT 2011.a A palette of climates for Gliese 581g. Astrophys. J. Lett. 726:1L8
    [Google Scholar]
  23. Pierrehumbert RT 2011.b Principles of Planetary Climate Cambridge, UK: Cambridge Univ. Press
    [Google Scholar]
  24. Pierrehumbert RT, Ding F 2016. Dynamics of atmospheres with a non-dilute condensible component. 472:219020160107
    [Google Scholar]
  25. Pierrehumbert RT, Swanson KL 1995. Baroclinic instability. Annu. Rev. Fluid Mech. 27:419–67
    [Google Scholar]
  26. Plumb RA, Hou AY 1992. The response of a zonally symmetric atmosphere to subtropical thermal forcing: threshold behavior. J. Atmos. Sci. 49:191790–99
    [Google Scholar]
  27. Polichtchouk I, Cho JY 2012. Baroclinic instability on hot extrasolar planets. Mon. Not. R. Astron. Soc. 424:21307–26
    [Google Scholar]
  28. Read P 1986. Super-rotation and diffusion of axial angular momentum: II. A review of quasi-axisymmetric models of planetary atmospheres. Q. J. R. Meteorol. Soc. 112:471253–72
    [Google Scholar]
  29. Showman AP, Polvani LM 2010. The Matsuno-Gill model and equatorial superrotation. Geophys. Res. Lett. 37:18L18811
    [Google Scholar]
  30. Showman AP, Polvani LM 2011. Equatorial superrotation on tidally locked exoplanets. Astrophys. J. 738:171
    [Google Scholar]
  31. Showman AP, Wordsworth RD, Merlis TM, Kaspi Y 2013. Atmospheric circulation of terrestrial exoplanets. Comparative Climatology of Terrestrial Planets SJ Mackwell, AA Simon-Miller, JW Harder, MA Bullock277–326 Tucson, AZ: Univ. Ariz. Press
    [Google Scholar]
  32. Sobel AH, Nilsson J, Polvani LM 2001. The weak temperature gradient approximation and balanced tropical moisture waves. J. Atmos. Sci. 58:233650–65
    [Google Scholar]
  33. Tsai SM, Dobbs-Dixon I, Gu PG 2014. Three-dimensional structures of equatorial waves and the resulting super-rotation in the atmosphere of a tidally locked hot Jupiter. Astrophys. J. 793:141
    [Google Scholar]
  34. Turbet M, Leconte J, Selsis F, Bolmont E, Forget F et al. 2016. The habitability of Proxima Centauri b-II. Possible climates and observability. Astron. Astrophys. 596:A112
    [Google Scholar]
  35. Vallis GK 2006. Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-Scale Circulation Cambridge, UK: Cambridge Univ. Press
    [Google Scholar]
  36. Wang P, Mitchell JL 2014. Planetary ageostrophic instability leads to superrotation. Geophys. Res. Lett. 41:124118–26
    [Google Scholar]
  37. Williams IN, Pierrehumbert RT, Huber M 2009. Global warming, convective threshold and false thermostats. Geophys. Res. Lett. 36:21L21805
    [Google Scholar]
  38. Zhang X, Showman AP 2017. Effects of bulk composition on the atmospheric dynamics on close-in exoplanets. Astrophys. J. 836:173
    [Google Scholar]
/content/journals/10.1146/annurev-fluid-010518-040516
Loading
/content/journals/10.1146/annurev-fluid-010518-040516
Loading

Data & Media loading...

Supplementary Data

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error