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An equatorial oscillation in Saturn’s middle atmosphere

Nature volume 453, pages 200–202 (2008)Cite this article

Abstract

The middle atmospheres of planets are driven by a combination of radiative heating and cooling, mean meridional motions, and vertically propagating waves (which originate in the deep troposphere). It is very difficult to model these effects and, therefore, observations are essential to advancing our understanding of atmospheres. The equatorial stratospheres of Earth and Jupiter oscillate quasi-periodically on timescales of about two and four years, respectively, driven by wave-induced momentum transport1,2,3,4,5. On Venus and Titan, waves originating from surface–atmosphere interaction and inertial instability are thought to drive the atmosphere to rotate more rapidly than the surface (superrotation). However, the relevant wave modes have not yet been precisely identified. Here we report infrared observations showing that Saturn has an equatorial oscillation like those found on Earth and Jupiter, as well as a mid-latitude subsidence that may be associated with the equatorial motion. The latitudinal extent of Saturn’s oscillation shows that it obeys the same basic physics as do those on Earth and Jupiter. Future highly resolved observations of the temperature profile together with modelling of these three different atmospheres will allow us determine the wave mode, the wavelength and the wave amplitude that lead to middle atmosphere oscillation.

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Figure 1: Saturn’s equatorial oscillation.
Figure 2: Vertical–zonal map of ethane abundance.
Figure 3: Radiative cooling rates in the northern and southern hemispheres.

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References

  1. Andrews, D. G., Holton, J. R. & Leovy, C. B. Middle Atmosphere Dynamics (Academic, New York, 1987)

    Google Scholar 

  2. Baldwin, M. P. et al. The quasi-biennial oscillation. Rev. Geophys. 39, 179–230 (2001)

    Article  ADS  Google Scholar 

  3. Leovy, C. B., Friedson, A. J. & Orton, G. S. The quasiquadrennial oscillation of Jupiter’s equatorial stratosphere. Nature 354, 380–382 (1991)

    Article  ADS  Google Scholar 

  4. Friedson, A. J. New observations and modelling of a QBO-like oscillation in Jupiter’s stratosphere. Icarus 137, 34–55 (1999)

    Article  ADS  Google Scholar 

  5. Flasar, F. M. et al. An intense stratospheric jet on Jupiter. Nature 427, 132–135 (2004)

    Article  ADS  CAS  Google Scholar 

  6. Barnet, C. D., Beebe, R. F. & Conrath, B. J. A seasonal radiative-dynamic model of Saturn’s troposphere. Icarus 98, 94–107 (1992)

    Article  ADS  Google Scholar 

  7. Bézard, B. & Gautier, D. A seasonal climate model of the atmospheres of the giant planets at the Voyager encounter time. I. Saturn’s stratosphere. Icarus 60, 296–310 (1985)

    Article  ADS  Google Scholar 

  8. Conrath, B. J., Gierasch, P. J. & Leroy, S. S. Temperature and circulation in the stratosphere of the outer planets. Icarus 83, 255–281 (1990)

    Article  ADS  Google Scholar 

  9. Moses, J. I. & Greathouse, T. K. Latitudinal and seasonal models of stratospheric photochemistry on Saturn: Comparision with infrared data from IRTF/TEXES. J. Geophys. Res. 110, 09007 (2005)

    Article  Google Scholar 

  10. Flasar, F. M. et al. Exploring the Saturn system in the thermal infrared: The Composite Infrared Spectrometer. Space Sci. Rev. 115, 169–297 (2004)

    Article  ADS  CAS  Google Scholar 

  11. Flasar, F. M. et al. Temperatures, winds, and composition in the Saturnian system. Science 307, 1247–1251 (2005)

    Article  ADS  CAS  Google Scholar 

  12. Greathouse, T. K. et al. Meridional variations of temperature, C2H2 and C2H6 abundances in Saturn’s stratosphere at southern summer solstice. Icarus 177, 18–31 (2005)

    Article  ADS  CAS  Google Scholar 

  13. Orton, G. S. et al. Thermal maps of Jupiter: Spatial organization and time dependence of stratospheric temperatures, 1980 to 1990. Science 252, 537–542 (1991)

    Article  ADS  CAS  Google Scholar 

  14. Simon-Miller, A. A., Poston, B. W., Orton, G. S. & Fisher, B. Wind variations in Jupiter’s equatorial atmosphere: A QQO counterpart? Icarus 186, 192–203 (2007)

    Article  ADS  Google Scholar 

  15. Orton, G. S. et al. Semi-annual oscillations in Saturn’s low-latitude stratospheric temperatures. Nature doi: 10.1038/nature06897 (this issue)

  16. Lindzen, R. S. & Holton, J. R. A theory of the quasi-biennial oscillation. J. Atmos. Sci. 25, 1095–1107 (1968)

    Article  ADS  Google Scholar 

  17. Holton, J. R. & Lindzen, R. S. An updated theory for the quasi-biennial cycle of the tropical troposphere. J. Atmos. Sci. 29, 1076–1080 (1972)

    Article  ADS  Google Scholar 

  18. Gray, L. J. & Pyle, J. A. A two-dimensional model of the quasi-biennial oscillation in ozone. J. Atmos. Sci. 46, 203–220 (1989)

    Article  ADS  Google Scholar 

  19. Dunkerton, T. J. Nonlinear propagation of zonal winds in an atmosphere with Newtonian cooling and equatorial wavedriving. J. Atmos. Sci. 48, 236–263 (1991)

    Article  ADS  Google Scholar 

  20. Li, X. & Read, P. L. A mechanical model of the quasi-quadrennial oscillation in Jupiter’s stratosphere. Planet. Space Sci. 48, 637–669 (2000)

    Article  ADS  Google Scholar 

  21. Beebe, R. F., Barnet, C., Sada, P. V. & Murrell, A. S. The onset and growth of the 1990 equatorial disturbance on Saturn. Icarus 95, 163–172 (1992)

    Article  ADS  Google Scholar 

  22. Sanchez-Lavega, A. Observations of Saturn’s Ribbon Wave 14 years after Its discovery. Icarus 158, 272–275 (2002)

    Article  ADS  Google Scholar 

  23. Achterberg, R. K. & Flasar, F. M. Planetary-scale thermal waves in Saturn’s upper troposphere. Icarus 119, 350–369 (1996)

    Article  ADS  Google Scholar 

  24. Schinder, P. J. et al. Vertically propagating waves in the upper atmosphere of Saturn from Cassini radio occultations. (AGU Fall Meeting Abstract No. P23D-06, 2005)

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Authors and Affiliations

  1. LESIA, Observatoire de Paris, Université Pierre et Marie Curie, CNRS, Paris 7, Meudon F-92195, France ,

    T. Fouchet, S. Guerlet & B. Bézard

  2. Departments of Earth and Planetary Sciences & Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA,

    D. F. Strobel

  3. NASA/Goddard Space Flight Center, Code 693, Greenbelt, Maryland 20771, USA ,

    A. A. Simon-Miller & F. M. Flasar

Authors
  1. T. Fouchet
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  2. S. Guerlet
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  3. D. F. Strobel
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  4. A. A. Simon-Miller
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  5. B. Bézard
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  6. F. M. Flasar
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Correspondence to T. Fouchet.

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The file contains Supplementary Notes, Supplementary Table 1 and Supplementary Figures 1-2 with Legends. (PDF 396 kb)

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Fouchet, T., Guerlet, S., Strobel, D. et al. An equatorial oscillation in Saturn’s middle atmosphere. Nature 453, 200–202 (2008). https://doi.org/10.1038/nature06912

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