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Detection of hydrogen sulfide above the clouds in Uranus’s atmosphere

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Abstract

Visible-to-near-infrared observations indicate that the cloud top of the main cloud deck on Uranus lies at a pressure level of between 1.2 bar and 3 bar. However, its composition has never been unambiguously identified, although it is widely assumed to be composed primarily of either ammonia or hydrogen sulfide (H2S) ice. Here, we present evidence of a clear detection of gaseous H2S above this cloud deck in the wavelength region 1.57–1.59 μm with a mole fraction of 0.4–0.8 ppm at the cloud top. Its detection constrains the deep bulk sulfur/nitrogen abundance to exceed unity (>4.4–5.0 times the solar value) in Uranus’s bulk atmosphere, and places a lower limit on the mole fraction of H2S below the observed cloud of \((1.0-2.5)\times 1{0}^{-5}\). The detection of gaseous H2S at these pressure levels adds to the weight of evidence that the principal constituent of 1.2–3-bar cloud is likely to be H2S ice.

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Fig. 1: The appearance and spectrum of Uranus at the near-infrared wavelengths observed by Gemini/NIFS and associated absorption spectra of CH4, NH3 and H2S.
Fig. 2: Pressure variation of temperature and condensable abundances assumed in this study for Uranus.
Fig. 3: Fits to average Gemini/NIFS observation of Uranus, made on 2 November 2010 at 15.3° N, using three different assumptions for the a priori imaginary refractive index spectrum, and excluding H2S and NH3 absorption.
Fig. 4: Fits to the coadded Gemini/NIFS observation of Uranus in the wavelength range 1.56–1.6 μm.

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References

  1. de Kleer, K., Luszcz-Cook, S., de Pater, I., Ádámkovics, M. & Hammel, H. B. Clouds and aerosols on Uranus: radiative transfer modeling of spatially-resolved near-infrared Keck spectra. Icarus 256, 120–137 (2015).

    Article  ADS  Google Scholar 

  2. Irwin, P. G. J. et al. The application of new methane line absorption data to Gemini-N/NIFS and KPNO/FTS observations of Uranus’ near-infrared spectrum. Icarus 220, 369–382 (2012).

    Article  ADS  Google Scholar 

  3. Sromovsky, L. A., Fry, P. M. & Kim, J. H. Methane on Uranus: the case for a compact CH4 cloud layer at low latitudes and a severe CH4 depletion at high latitudes based on a re-analysis of Voyager occultation measurements and STIS spectroscopy. Icarus 215, 292–312 (2011).

    Article  ADS  Google Scholar 

  4. Weidenschilling, S. J. & Lewis, J. S. Atmospheric and cloud structures of the Jovian planets. Icarus 20, 465–476 (1973).

    Article  ADS  Google Scholar 

  5. de Pater, I., Romani, P. N. & Atreya, S. K. Possible microwave absorption by H2S gas in Uranus’ and Neptune’s atmospheres. Icarus 91, 220–233 (1991).

    Article  ADS  Google Scholar 

  6. de Pater, I., Romani, P. N. & Atreya, S. K. Uranus’ deep atmosphere revealed. Icarus 82, 288–313 (1989).

    Article  ADS  Google Scholar 

  7. de Pater, I. & Massie, S. Models of the millimeter-centimeter spectra of the giant planets. Icarus 62, 143–171 (1985).

    Article  ADS  Google Scholar 

  8. Cameron, A. G. W. in Essays in Nuclear Astrophysics (eds C. A. Barnes et al.) 23–43 (Cambridge Univ. Press, London, 1982).

  9. Niemann, H. B. et al. The composition of the Jovian atmosphere as determined by the Galileo probe mass spectrometer. J. Geophys. Res. 103, 22831–22845 (1998).

    Article  ADS  Google Scholar 

  10. Boissier, J. et al. Interferometric imaging of the sulfur-bearing molecules H2S, SO and CS in comet C/1995 O1 (Hale-Bopp). Astron. Astrophys. 475, 1131–1144 (2007).

    Article  ADS  Google Scholar 

  11. Eberhardt, P., Meier, R., Krankowsky, D. & Hodges, P. R. Methanol and hydrogen sulfide in comet P/Halley. Astron. Astrophys. 288, 315–329 (1994).

    ADS  Google Scholar 

  12. Noll, K. S. et al. HST spectroscopic observations of Jupiter after the collision of comet Shoemaker-Levy 9. Science 267, 1307–1313 (1995).

    Article  ADS  Google Scholar 

  13. Lellouch, E. Chemistry induced by the impacts: observations. In Proc. Space Telescope Science Institute Workshop (eds Noll, K. S. et al.) 213–242 (Vol. 156, IAU Colloquium, Cambridge Univ. Press, Cambridge, 1996).

  14. Campargue, A., Leshchishina, O., Wang, L., Mondelain, D. & Kassi, S. The WKLMC empirical line lists (5852–7919 cm−1) for methane between 80 K and 296 K: ‘final’ lists for atmospheric and planetary applications. J. Molec. Spectrosc. 291, 16–22 (2013).

    Article  ADS  Google Scholar 

  15. Rothman, L. S. et al. The HITRAN2012 molecular spectroscopic database. J. Quant. Spectrosc. Ra. 130, 4–50 (2013).

    Article  ADS  Google Scholar 

  16. Irwin, P. G. J. et al. Uranus’ cloud structure and seasonal variability from Gemini-North and UKIRT observations. Icarus 212, 339–350 (2011).

    Article  ADS  Google Scholar 

  17. Irwin, P. G. J. et al. Further seasonal changes in Uranus’ cloud structure observed by Gemini-North and UKIRT. Icarus 218, 47–55 (2012).

    Article  ADS  Google Scholar 

  18. Irwin, P. G. J. et al. The NEMESIS planetary atmosphere radiative transfer and retrieval tool. J. Quant. Spectrosc. Ra . 109, 1136–1150 (2008).

    Article  ADS  Google Scholar 

  19. Karkoschka, E. & Tomasko, M. The haze and methane distributions on Uranus from HST-STIS spectroscopy. Icarus 202, 287–309 (2009).

    Article  ADS  Google Scholar 

  20. Fray, N. & Schmitt, B. Sublimation of ices of astrophysical interest: a bibliographic review. Plan. Space Sci. 57, 2053–2080 (2009).

    Article  ADS  Google Scholar 

  21. Irwin, P. G. J. et al. Reanalysis of Uranus’ cloud scattering properties from IRTF/SpeX observations using a self-consistent scattering cloud retrieval scheme. Icarus 250, 462–476 (2015).

    Article  ADS  Google Scholar 

  22. Karkoschka, E. & Tomasko, M. Methane absorption coefficients for the jovian planets from laboratory, Huygens, and HST data. Icarus 205, 674–694 (2010).

    Article  ADS  Google Scholar 

  23. Sromovsky, L. A. & Fry, P. M. Spatially resolved cloud structure on Uranus: implications of near-IR adaptive optics imaging. Icarus 192, 527–557 (2007).

    Article  ADS  Google Scholar 

  24. Orton, G. S. et al. Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. determination of the mean temperature of the upper troposphere and stratosphere. Icarus 243, 494–513 (2014).

    Article  ADS  Google Scholar 

  25. Grevesse, N., Asplund, M. & Sauval, A. D. The solar chemical composition. Space Sci. Rev. 130, 105–114 (2007).

    Article  ADS  Google Scholar 

  26. Lodders. K. in Principles and Perspectives in Cosmochemistry (eds Goswami, A. & Reddy, B. E.) 379–417 (Astrophysics and Space Science Proc., Springer-Verlag Berlin Heidelberg, Berlin, 2010).

  27. Campargue, A. et al. An empirical line list for methane in the 1.26–1.71 μm region for planetary investigations (T = 80–300 K). Application to Titan. Icarus 219, 110–128 (2012).

    Article  ADS  Google Scholar 

  28. Feuchtgruber, H. et al. The D/H ratio in the atmospheres of Uranus and Neptune from Herschel-PACS observations. Astron. Astrophys. 551, A126 (2013).

    Article  Google Scholar 

  29. Lécluse, C., Robert, F., Gautier, D. & Guiraud, M. Deuterium enrichment in giant planets. Planet. Space Sci. 44, 1579–1592 (1996).

    Article  ADS  Google Scholar 

  30. Pine, A. S. Self-, N2-, O2-, H2-, Ar-, and He- broadening in the v 3 band Q branch of CH4. J. Chem. Phys. 97, 773–785 (1992).

    Article  ADS  Google Scholar 

  31. Amundsen, D. S. et al. Accuracy tests of radiation schemes used in hot Jupiter global circulation models. Astron. Astrophys. 564, A59 (2014).

    Article  Google Scholar 

  32. Margolis, J. S. Hydrogen broadening and collision-induced line shifts of methane at 4200 cm−1. J. Quant. Spectrosc. Ra. 49, 71–79 (1993).

    Article  ADS  Google Scholar 

  33. Varanasi, P. & Chudamani, S. The temperature dependence of lineshifts, linewidths and line intensities of methane at low temperatures. J. Quant. Spectrosc. Ra. 43, 1–11 (1990).

    Article  ADS  Google Scholar 

  34. Hartmann, J.-M. et al. A far wing lineshape for H2-broadened CH4 infrared transitions. J. Quant. Spectrosc. Ra. 72, 117–122 (2002).

    Article  ADS  Google Scholar 

  35. de Bergh, C. et al. Applications of a new set of methane line parameters to the modeling of Titan’s spectrum in the 1.58 μm window. Planet. Space Sci. 61, 85–98 (2012).

    Article  ADS  Google Scholar 

  36. Sromovsky, L. A., Fry, P. M., Boudon, V., Campargue, A. & Nikitin, A. Comparison of line-by-line and band models of near-IR methane absorption applied to outer planet atmospheres. Icarus 218, 1–23 (2012).

    Article  ADS  Google Scholar 

  37. Azzam, A. A. A., Tennyson, J., Yurchenko, S. N. & Naumenko, O. V. ExoMol molecular line lists—XVI: the rotation-vibration spectrum of hot H2S. Mon. Not. Roy. Ast. Soc. 460, 4063–4074 (2016).

    Article  ADS  Google Scholar 

  38. Lacis, A. A. & Oinas, V. A description of the correlated-k distribution method for modelling nongray gaseous absorption, thermal emission, and multiple scattering in vertically inhomogeneous atmospheres. J. Geophys. Res. 96, 9027–9063 (1991).

    Article  ADS  Google Scholar 

  39. Plass, G. N., Kattawar, G. W. & Catchings, F. E. Matrix operator method of radiative transfer. 1: Rayleigh scattering. Appl. Opt. 12, 314–329 (1973).

    Article  ADS  Google Scholar 

  40. Borysow, A. Modeling of collision-induced infrared absorption spectra of H2–H2 pairs in the fundamental band at temperatures from 20 to 300 K. Icarus 92, 273–279 (1991).

    Article  ADS  Google Scholar 

  41. Borysow, A. New model of collision-induced infrared absorption spectra of H2–He pairs in the 2–2.5 μm range at temperatures from 20 to 300 K—an update. Icarus 96, 169–175 (1992).

    Article  ADS  Google Scholar 

  42. Zheng, C. & Borysow, A. Modeling of collision-induced infrared absorption spectra of H2 pairs in the first overtone band at temperatures from 20 to 500 K. Icarus 113, 84–90 (1995).

    Article  ADS  Google Scholar 

  43. Menang, K. P., Coleman, M. D., Gardiner, T. D., Ptashnik, I. V. & Shine, K. P. A high-resolution near-infrared extraterrestrial solar spectrum derived from ground-based Fourier transform spectrometer measurements. J. Geophys. Res. 118, 5319–5331 (2013).

    Article  Google Scholar 

  44. Fiorenza, C. & Formisano, V. A solar spectrum for PFS data analysis. Planet. Space Sci. 53, 1009–1016 (2005).

    Article  ADS  Google Scholar 

  45. Thuillier, G. et al. The solar spectral irradiance from 200 to 2400 nm as measured by the SOLSPEC spectrometer from the ATLAS and EURECA missions. Sol. Phys. 214, 1–22 (2003).

    Article  ADS  Google Scholar 

  46. Sheik-Bahae, M. in Encyclopedia of Modern Optics (eds Guenther, R. D. et al.) 234–239 (Academic Press, Amsterdam, 2005).

  47. Mishchenko, M. I., Travis, L. D., Khan, R. A. & West, R. A. Modeling phase functions for dustlike tropospheric aerosols using a shape mixture of randomly oriented polydisperse spheroids. J. Geophys. Res. 102, 16831–16847 (1997).

    Article  ADS  Google Scholar 

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Acknowledgements

We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research and to our support astronomers: R. McDermid and C. Trujillo. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). We thank L. Sromovsky for providing the code used to generate our Rayleigh-scattering opacities. G.A.O. was supported by NASA funding to the Jet Propulsion Laboratory, California Institute of Technology. L.N.F. was supported by a Royal Society Research Fellowship at the University of Leicester.

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Authors and Affiliations

  1. Department of Physics (Atmospheric, Oceanic and Planetary Physics), University of Oxford, Oxford, UK

    Patrick G. J. Irwin, Daniel Toledo & Ryan Garland

  2. School of Earth Sciences, University of Bristol, Bristol, UK

    Nicholas A. Teanby

  3. Department of Physics & Astronomy, University of Leicester, Leicester, UK

    Leigh N. Fletcher

  4. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

    Glenn A. Orton

  5. LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 6, Université Paris-Diderot, Sorbonne Paris Cité, Meudon, France

    Bruno Bézard

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Contributions

P.G.J.I. wrote the proposal to make the original observations, and reduced and reanalysed the data using the NEMESIS code; B.B. and R.G. assisted in identifying and validating the line data used. G.A.O. provided the Spitzer temperature–pressure profile used. All authors contributed to the analysis and interpretation of the results, and all authors wrote the final paper.

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Correspondence to Patrick G. J. Irwin.

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Irwin, P.G.J., Toledo, D., Garland, R. et al. Detection of hydrogen sulfide above the clouds in Uranus’s atmosphere. Nat Astron 2, 420–427 (2018). https://doi.org/10.1038/s41550-018-0432-1

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