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Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki

A Corrigendum to this article was published on 03 October 2017

This article has been updated

Abstract

The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet’s rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet’s nightside escapes to space at narrow spectral windows of the near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m s−1 at low to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m s−1 using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide clues to the dynamics of Venus’s atmospheric superrotation.

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Figure 1: High-pass-filtered radiance at 2.26 μm, horizontal velocities and associated trajectories for 11–12 July 2016.
Figure 2: Zonal wind and vorticity in the lower and middle cloud regions in 11–12 July 2016.
Figure 3: Close up to show the movement of radiance ‘holes’ (bright spots) on 11–12 July 2016.
Figure 4: Zonal winds at the cloud top derived from UVI (365 nm) and IR2 (2.02 μm) data for 11 July 2016.
Figure 5: Zonal winds in the lower cloud at various times.

Change history

  • 29 August 2017

    In the version of this Article originally published, the directional labels on the x-axes of Figures 1a–d and 2a were W (west), when they should have been E (east). In Figures 2b, 4a,b and 5a–c, the x-axes were given as longitude, when they should have been average wind speed. These errors have been corrected in the online version of the Article.

References

  1. Schubert, G. Venus (eds Hunten, D. M., Colin, L., Donahue, T. M.& Moroz, V. I.) 681–765 (Univ. Arizona Press, 1983).

    Google Scholar 

  2. Schubert, G. et al. Structure and circulation of the Venus atmosphere. J. Geophys. Res. 85, 8007–8025 (1980).

    Article  Google Scholar 

  3. Marov, M. et al. Venera 8: measurements of temperature, pressure, and wind velocity on the illuminated side of Venus. J. Atmos. Sci. 30, 1210–1214 (1973).

    Article  Google Scholar 

  4. Antsibor, N. M. et al. Estimates of wind velocity and turbulence from relayed Doppler measurements of the velocity of the descent vehicles of the Venera 9 and Venera 10 automatic space probes. Kosm. Issled. 14, 714–721 (1976).

    Google Scholar 

  5. Schubert, G. & Whitehead, J. A. Moving flame experiment with liquid mercury: possible implications for the Venus atmosphere. Science 163, 71–72 (1969).

    Article  Google Scholar 

  6. Fels, S. B. & Lindzen, R. S. The interaction of thermally excited gravity waves with mean flows. Geophys. Astrophys. Fluid Dyn. 6, 149–191 (1974).

    Article  Google Scholar 

  7. Gierasch, P. J. Meridional circulation and the maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 32, 1038–1044 (1975).

    Article  Google Scholar 

  8. Matsuda, Y. Dynamics of the four-day circulation in the Venus atmosphere. J. Meteorol. Soc. Jpn 58, 443–470 (1980).

    Article  Google Scholar 

  9. Yamamoto, M. & Tanaka, H. Formation and maintenance of the 4-day circulation in the Venus middle atmosphere. J. Atmos. Sci. 54, 1472–1489 (1997).

    Article  Google Scholar 

  10. Yamamoto, M. & Takahashi, M. The fully developed superrotation simulated by a general circulation model of a Venus-like atmosphere. J. Atmos. Sci. 60, 561–574 (2003).

    Article  Google Scholar 

  11. Takagi, M. & Matsuda, Y. Effects of thermal tides on the Venus atmospheric superrotation. J. Geophys. Res. 112, D09112 (2007).

    Article  Google Scholar 

  12. Lebonnois, S. et al. Superrotation of Venus’ atmosphere analyzed with a full general circulation model. J. Geophys. Res. 115, E06006 (2010).

    Article  Google Scholar 

  13. Lebonnois, S. et al. Models of Venus atmosphere. in Towards Understanding the Climate of Venus Vol. 11 (eds Bengtsson, L., Bonnet, R.-M., Grinspoon, D., Koumoutsaris, S., Lebonnois, S. & Titov, D.) 129–156 (ISSI Scientific Report Series, Springer, 2013).

    Chapter  Google Scholar 

  14. Mendonça, J. M. & Read, P. L. Exploring the Venus global super-rotation using a comprehensive general circulation model. Planet. Space Sci. 134, 1–18 (2016).

    Article  Google Scholar 

  15. Allen, D. A. & Crawford, J. W. Cloud structure on the dark side of Venus. Nature 307, 222–224 (1984).

    Article  Google Scholar 

  16. Crisp, D. et al. The nature of the near-infrared features on the Venus night side. Science 246, 506–509 (1989).

    Article  Google Scholar 

  17. Pollack, J. B., Toon, O. B. & Boese, R. Greenhouse models of Venus’ high surface temperature, as constrained by Pioneer Venus measurements. J. Geophys. Res. 85, 8223–8231 (1980).

    Article  Google Scholar 

  18. Knollenberg, R. G. & Hunten, D. H. The microphysics of the clouds of Venus: results of the Pioneer Venus Particle Size Spectrometer Experiment. J. Geophys. Res. 85, 8038–8058 (1980).

    Google Scholar 

  19. Carlson, R. W. & Baines, K. H. Galileo infrared imaging spectroscopy measurements at Venus. Science 253, 1541–1548 (1991).

    Article  Google Scholar 

  20. Sánchez-Lavega, A. et al. Variable winds on Venus mapped in three dimensions. Geophys. Res. Lett. 35, L13204 (2008).

    Article  Google Scholar 

  21. Hueso, R., Peralta, J. & Sánchez-Lavega, A. Assessing the long-term variability of Venus winds at cloud level from VIRTIS–Venus Express. Icarus 217, 585–598 (2012).

    Article  Google Scholar 

  22. Limaye, S., Warell, J., Bhatt, B. C., Fry, P. M. & Young, E. F. Multi-observatory observations of night-side of Venus at 2.3 micron-atmospheric circulation from tracking of cloud features. Bull. Astron. Soc. India 34, 189 (2006).

    Google Scholar 

  23. Newman, M., Schubert, G., Kliore, A. J. & Patel, I. R. Zonal winds in the middle atmosphere of Venus from Pioneer Venus radio occultation data. J. Atmos. Sci. 41, 1901–1913 (1984).

    Article  Google Scholar 

  24. Kerzhanovich, V. V. & Limaye, S. S. Circulation of the atmosphere from the surface to 100 km. Adv. Space Res. 5, 59–83 (1985).

    Article  Google Scholar 

  25. Crisp, D. et al. Ground-based near-infrared imaging observations of Venus during the Galileo encounter. Science 253, 1538–1541 (1991).

    Article  Google Scholar 

  26. Nakamura, M. et al. Overview of Venus orbiter, Akatsuki. Earth Planets Space 63, 443–457 (2011).

    Article  Google Scholar 

  27. Nakamura, M. et al. AKATSUKI returns to Venus. Earth Planets Space 68, 75 (2016).

    Article  Google Scholar 

  28. Fukuhara, T. et al. Large stationary gravity wave in the atmosphere of Venus. Nat. Geosci. 10, 85–88 (2017).

    Article  Google Scholar 

  29. Satoh, T. et al. Development and in-flight calibration of IR2: 2-μm camera onboard Japan’s Venus orbiter, Akatsuki. Earth Planets Space 68, 74 (2016).

    Article  Google Scholar 

  30. Ikegawa, S. & Horinouchi, T. Improved automatic estimation of winds at the cloud top of Venus using superposition of cross-correlation surfaces. Icarus 271, 98–119 (2016).

    Article  Google Scholar 

  31. Horinouchi, T. et al. Image velocimetry for clouds with relaxation labeling based on deformation consistency. Meas. Sci. Technol. 28, 085301 (2017).

    Article  Google Scholar 

  32. Kouyama, T., Imamura, T., Nakamura, M., Satoh, T. & Futaana, Y. Long-term variation in the cloud-tracked zonal velocities at the cloud top of Venus deduced from Venus Express VMC images. J. Geophys. Res. 118, 37–46 (2013).

    Article  Google Scholar 

  33. Peralta, J., Hueso, R. & Sánchez-Lavega, A. A reanalysis of Venus winds at two cloud levels from Galileo SSI images. Icarus 190, 469–477 (2007).

    Article  Google Scholar 

  34. Grinspoon, D. H. et al. Probing Venus’s cloud structure with Galileo NIMS. Planet. Space Sci. 41, 515–542 (1993).

    Article  Google Scholar 

  35. McGouldrick, K. & Toon, O. B. An investigation of possible causes of the holes in the condensational Venus cloud using a microphysical cloud model with a radiative-dynamical feedback. Icarus 191, 1–24 (2007).

    Article  Google Scholar 

  36. Imamura, T. & Hashimoto, G. L. Microphysics of Venusian clouds in rising tropical air. J. Atmos. Sci. 58, 3597–3612 (2001).

    Article  Google Scholar 

  37. Limaye, S. S. Venus atmospheric circulation: known and unknown. J. Geophys. Res. 112, E04S09 (2007).

    Article  Google Scholar 

  38. Kashimura, H. & Yoden, S. Regime diagrams of solutions in an idealized quasi-axisymmetric model for superrotation of planetary atmospheres. J. Meteorol. Soc. Jpn 93, 309–326 (2015).

    Article  Google Scholar 

  39. Zasova, L. V., Ignatiev, N., Khatuntsev, I. & Linkin, V. Structure of the Venus atmosphere. Planet. Space Sci. 55, 1712–1728 (2007).

    Article  Google Scholar 

  40. Lebonnois, S., Sugimoto, N. & Gilli, G. Wave analysis in the atmosphere of Venus below 100-km altitude, simulated by the LMD Venus GCM. Icarus 278, 38–51 (2016).

    Article  Google Scholar 

  41. Ogohara, K. et al. Automated cloud tracking system for the Akatsuki Venus Climate Orbiter data. Icarus 217, 661–668 (2012).

    Article  Google Scholar 

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Acknowledgements

We sincerely thank the numerous people who contributed to create and operate Akatsuki spacecraft. This study is supported by the following grants: JSPS KAKENHI 15K17767, 16H02225 and 16H02231, 16K17816; NASA Grant NNX16AC79G; JAXA’s International Top Young Fellowship (ITYF). All figures and the supplementary movie were created using the GFD-Dennou Club graphic library, DCL.

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Contributions

T.H. developed automated cloud tracking and error evaluation methods, corrected the bore sight of IR2 nightside images, conducted tracking and interpreted the results. S.-y.M. and K.O. contributed cloud tracking programing. T.S., T.M.S., K.-i.S., T.I. and M.N. conducted IR2 observations and contributed to the operation of Akatsuki and observation planning. K.O., T.K., H.K. and M.T. developed the bore-sight correction applied to dayside images, and they also developed geographical mapping. J.P. conducted manual tracking with IR2 data based on independent geographical mapping. T.S., J.P., T.K., S.S.L., M.T. and E.F.Y. helped scientific interpretation and the review of previous studies. S.W., M.Y. and A.Y. conducted UVI observations. E.F.Y. conducted IRTF observations and the tracking with them. K.M. contributed by optical and cloud-physical interpretation.

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Correspondence to Takeshi Horinouchi.

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Horinouchi, T., Murakami, Sy., Satoh, T. et al. Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki. Nature Geosci 10, 646–651 (2017). https://doi.org/10.1038/ngeo3016

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