Abstract
One of Titan's most intriguing attributes is its copious but featureless atmosphere. The Voyager 1 fly-by and occultation in 1980 provided the first radial survey of Titan's atmospheric pressure and temperature1,2 and evidence for the presence of strong zonal winds3. It was realized that the motion of an atmospheric probe could be used to study the winds, which led to the inclusion of the Doppler Wind Experiment4 on the Huygens probe5. Here we report a high resolution vertical profile of Titan's winds, with an estimated accuracy of better than 1 m s-1. The zonal winds were prograde during most of the atmospheric descent, providing in situ confirmation of superrotation on Titan. A layer with surprisingly slow wind, where the velocity decreased to near zero, was detected at altitudes between 60 and 100 km. Generally weak winds (∼1 m s-1) were seen in the lowest 5 km of descent.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Tyler, G. L. et al. Radio science investigations of the Saturn system with Voyager 1: Preliminary results. Science 212, 201–206 (1981)
Lindal, G. F. et al. The atmosphere of Titan: An analysis of the Voyager 1 radio occultation measurements. Icarus 53, 348–363 (1983)
Flasar, F. M., Samuelson, R. E. & Conrath, B. J. Titan's atmosphere: temperature and dynamics. Nature 292, 693–698 (1981)
Bird, M. K. et al. The Huygens Doppler Wind Experiment. Space Sci. Rev. 104, 613–640 (2002)
Lebreton, J.-P. et al. An overview of the descent and landing of the Huygens probe. Nature doi:10.1038/nature04347 (this issue)
Del Genio, A. D., Zhou, W. & Eichler, T. P. Equatorial superrotation in a slowly rotating GCM: Implications for Titan and Venus. Icarus 101, 1–17 (1993)
Hourdin, F. et al. Numerical simulation of the general circulation of the atmosphere of Titan. Icarus 117, 358–374 (1995)
Tokano, T., Neubauer, F. M., Laube, M. & McKay, C. P. Seasonal variation of Titan's atmospheric structure simulated by a general circulation model. Planet. Space Sci. 47, 493–520 (1999)
Luz, D., Hourdin, F., Rannou, P. & Lebonnois, S. Latitudinal transport by baroclinic waves in Titan's stratosphere. II. Results from a coupled dynamics-microphysics-photochemistry GCM. Icarus 166, 343–358 (2003)
Hubbard, W. B. et al. The occultation of 28 Sgr by Titan. Astron. Astrophys. 269, 541–563 (1993)
Bouchez, A. H. Seasonal Trends in Titan's Atmosphere: Haze, Wind and Clouds PhD thesis, California Inst. Technol. (2003); available at http://www.gps.caltech.edu/(antonin/thesis
Kostiuk, T. et al. Direct measurement of winds on Titan. Geophys. Res. Lett. 28, 2361–2364 (2000)
Porco, C. C. et al. Imaging of Titan from the Cassini spacecraft. Nature 434, 159–168 (2005)
Fulchignoni, M. et al. In situ measurements of the physical characteristics of Titan's atmosphere. Nature doi:10.1038/nature04314 (this issue)
Atkinson, D. H., Pollack, J. B. & Seiff, A. Measurement of a zonal wind profile on Titan by Doppler tracking of the Cassini entry probe. Radio Sci. 25, 865–882 (1990)
Counselman, C. C. III, Gourevitch, S. A., King, R. W. & Loriot, G. B. Zonal and meridional circulation of the lower atmosphere of Venus determined by radio interferometry. J. Geophys. Res. 85, 8026–8030 (1980)
Allison, M., Del Genio, A. D. & Zhou, W. Zero potential vorticity envelopes for the zonal-mean velocity of the Venus/Titan atmospheres. J. Atmos. Sci. 51, 694–702 (1994)
Brown, M. E., Bouchez, A. H. & Griffith, C. A. Direct detection of variable tropospheric clouds near Titan's south pole. Nature 420, 795–797 (2002)
Flasar, F. M. et al. Exploring the Saturn system in the thermal infrared: The Composite Infrared Spectrometer. Space Sci. Rev. 115, 169–297 (2004)
Flasar, F. M. et al. Titan's atmospheric temperatures, winds, and composition. Science 308, 975–978 (2005)
Kliore, A. J. et al. Cassini radio science. Space Sci. Rev. 115, 1–70 (2004)
Tomasko, M. G. et al. Rain, winds and haze during the Huygens probe's descent to Titan's surface. Nature doi:10.1038/nature04126 (this issue)
Flasar, F. M. & Conrath, B. J. in Proc. Symposium on Titan (ed. Kaldeich, B.) 89–99 (ESA-SP 338, ESA Publications, ESTEC, Noordwijk, The Netherlands, 1992)
Del Genio, A. D. & Zhou, W. Simulations of superrotation on slowly rotating planets: Sensitivity to rotation and initial condition. Icarus 120, 332–343 (1996)
Allison, M. in Proc. Symposium on Titan (ed. Kaldeich, B.) 113–118 (ESA SP-338, ESA Publications, ESTEC, Noordwijk, The Netherlands, 1992)
Tokano, T. Meteorological assessment of the surface temperatures on Titan: Constraints on the surface type. Icarus 173, 222–242 (2005)
Flasar, F. M., Allison, M. & Lunine, J. I. in Huygens Science Payload and Mission (ed. Wilson, A.) 287–298 (ESA-SP 1177, ESA Publications, ESTEC, Noordwijk, The Netherlands, 1997)
Dutta-Roy, R. & Bird, M. K. in Planetary Probe Atmospheric Entry and Descent Trajectory Analysis and Science (ed. Wilson, A.) 109–116 (ESA SP-544, ESA Publications, ESTEC, Noordwijk, The Netherlands, 2004)
Acknowledgements
This Letter presents results of a research project partially funded by the Deutsches Zentrum für Luft- und Raumfahrt (DLR). Parts of the research described here were carried out by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA, and by NASA's Goddard Institute for Space Studies. We thank R. Kohl, K.-P. Wagner and M. Heyl for their efforts during the DWE development programme. We appreciate the support provided by the National Radio Astronomy Observatory (NRAO) and the Australia Telescope National Facility (ATNF). NRAO is operated by Associated Universities, Inc., under a cooperative agreement with the NSF. The ATNF, managed by the Commonwealth Scientific and Industrial Research Organization (CSIRO), is funded by the Commonwealth of Australia.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.
Supplementary information
Supplementary Notes
This file contains the Supplementary Discussion, Supplementary Figures 1–3, Supplementary Tables 1–2. Supplementary Figure 1 details Huygens signal frequency measurements at the Green Bank and Parkes radio telescopes. Supplementary Figure 2 presents Huygens frequency measurements and predictions at the Green Bank Telescope. Supplementary Figure 3 details Huygens frequency measurements and predictions at the Parkes Telescope. Supplementary Table 1 lists radio telescopes participating in the Earth-based DWE network. Supplementary Table 2 presents the Radio link budget: Huygens-to-Green Bank Telescope. (PDF 70 kb)
Rights and permissions
About this article
Cite this article
Bird, M., Allison, M., Asmar, S. et al. The vertical profile of winds on Titan. Nature 438, 800–802 (2005). https://doi.org/10.1038/nature04060
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature04060
This article is cited by
-
Plasma-neutral gas interactions in various space environments: Assessment beyond simplified approximations as a Voyage 2050 theme
Experimental Astronomy (2022)
-
Science goals and new mission concepts for future exploration of Titan’s atmosphere, geology and habitability: titan POlar scout/orbitEr and in situ lake lander and DrONe explorer (POSEIDON)
Experimental Astronomy (2022)
-
The nightside cloud-top circulation of the atmosphere of Venus
Nature (2021)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
