models of venus' atmospheric...

Models of Venus' Atmospheric Circulation

NASA: http://solarviews.com/raw/venus/venusmar.jpg

RSZ + SS-AS

Schubert et al. 2007 Schubert et al. 2007

Atmospheric circulation is driven by two processes:*Upper atmosphere: subsolar-to-antisolar (SS-AS) circulation cell*Lower atmosphere: retrograde superrotating zonal (RSZ) flowThe RSZ has constant direction from the upper atmosphere to the surface (Counselmann et al., 1980) and maximum momentum perunit volume near 20 km (Schubert, 1983).

Source of RSZ

● Gold and Soter (1971) suggested solar gravitational torque, “provided by thermally-induced semidiurnal atmospheric tide.” Schubert (1983) and Gierasch et al. (1997) proved this was insufficient.

Gold and Soter (1971)

Source of RSZ● Tidal forces may contribute (Schofield and Taylor,

1983), but they are not strong enough (Gierasch, 1997).

● The momentum source must come from the solid planet.

● Gierasch (1975) suggested Hadly cells.

"HadleyCross-sec" by The original uploader was Dwindrim at English Wikipedia - Transferred from en.wikipedia to Commons by Andrei Stroe using CommonsHelper.. Licensed under CC BY-SA 1.0 via Commons - https://commons.wikimedia.org/wiki/File:HadleyCross-sec.jpg#/media/File:HadleyCross-sec.jpgGierasch (1975)

Young and Pollack (1977)

● First successful attempt to simulate RSZ, using weak Gierasch mechanism amplified by a vertical shear of the horizontal wind, aka Reynolds stress (Thompson, 1970).

● Vertical diffusion formula was later considered to have exaggerated the RSZ (Young and Pollack, 1980) and no wind was predicted below 30 km.

Young and Pollack, 1980

Del Genio and Zhou (1996)

● Models attempted to predict supperrotation for Venus and Titan with the mass of Earth's atmosphere.

● Introduced eddy transport through barotropic instability (Rossow and Williams, 1979) with strong Gierasch term and decoupled lower atmosphere.



● Cloud top equatorial speed is an order of magnitude too small.

● Required axisymmetric heating, ignoring the day-night cycle.


Yamamoto and Takahashi (2006a) and Hollingsworth et al. (2007)

● Both models were able to accurately predict RSZ at all altitudes in Venus.

● Both incorporated day-night cycle into Del Genio and Zhou's models to consider non-axisymmetric heating and a strong Gierasch mechanism (Hadley circulation) with additional momentum transport through eddies.

● Both required substantially larger thermal gradients in the lower atmosphere than had been observed.

Zonal wind with large lower atmospheric heating

Schubert et al. (2007)

Zonal wind with lower atmospheric heating consistent with Pioneer Venus


Zero potential vorticity profiles

● Allison et al. (1994) realized that the latitudinal profiles resemble that of zero potential vorticity envelope.

● The models may be underestimating the efficiency of RSZ

● Vorticity potentials map the intersection of angular momentum and potential temperature surfaces.

Allison et al. (1994)

Further problems: vortex circulation

● Left to right: Composition of Mariner 10 images, image from VIRTIS on Venus Express, Hurricane Fran (Limaye, 2007).

● “S-shaped” features near the “eye” of the storm.

Limaye (2007)

Further problems

● How much do thermal tides contribute?● What is the contribution of planetary-scale

waves? (Peralta et al. 2014)● So far, no simulation accurately models a

radiative transfer scheme.● What is the role of gravity waves in maintaining

and driving variations in the upper atmosphere, particularly the NO and O2 emissions?

Needed measurements


References● Allison, M., A. D. Del Genio, and W. Zhou (1994), Zero potential vorticity envelopes for the zonal-mean velocity of the Venus/Titan atmospheres,

J. Atmos. Sci., 51, 694–702.● Counselmann, C. C., S. A. Gourevitch, R. W. King, G. B. Loriot, and E. S. Ginsberg (1980), Zonal and meridional circulation of the lower

atmosphere of Venus determined by radio inteferometry, J. Geophys. Res., 85, 8026–8030.● Del Genio, A. D., and W. Zhou (1996), Simulations of superrotation on slowly rotating planets: Sensitivity to rotation and initial condition, Icarus,

120, 332–343.● Gierasch, P. J. (1975), Meridional circulation and the maintenance of the Venus atmospheric rotation, J. Atmos. Sci., 32, 1038–1044.● Gierasch, P. J., R. M. Goody, R. E. Young, D. Crisp, C. Edwards, R. Kahn, D. McCleese, D. Rider, A. Del Genio, R. Greeley, A. Hou, C. B. Leovy,

and M. Newman (1997), The general circulation of the Venus atmosphere: An assessment, in Venus II: Geology, Geophysics, Atmosphere, and Solar Wind Environment, edited by S. Bougher, D. Hunten, and R. Phillips, pp. 459–500, University of Arizona Press, Tucson.

● Gold, T., and S. Soter (1971), Atmospheric tides and the 4-day circulation on Venus, Icarus, 14, 16–20.● Hollingsworth, J. L., R. E. Young, G. Schubert , C. C. Covey, and A. S. Grossman (2007), A simple-physics global circulation model for Venus:

Sensitivity assessments of atmospheric superrotation, Geophys. Res. Lett., 34, L05202, doi:10.1029/2006GL028567.● Limaye, S. S. (2007). Venus atmospheric circulation: Known and unknown. J. Geophys. Res, 112, E04S09● Peralta, J. et al. Analytical Solution for Waves in Planets with Atmospheric Superrotation. II. Lamb, Surface, and Centrifugal Waves. The

Astrophysical Journal Supplement Series 2014 213 18● IOPscience● Rossow, W. B., and G. P. Williams (1979), Large-scale motion in the Venus stratosphere, J. Atmos. Sci., 36, 377–389.● Schofield, J. T., and F. W. Taylor (1983), Measurements of the mean, solar-fixed temperature and cloud structure of the middle atmosphere of

Venus, Quart. J. R. Meterol. Soc., 109, 57–80.● Schubert, G., Bougher, S. W., Covey, C. C., Del Genio, A. D., Grossman, A. S., Hollingsworth, J. L., Limaye, S. S. and Young, R. E. (2007) Venus

Atmosphere Dynamics: A Continuing Enigma, in Exploring Venus as a Terrestrial Planet (eds L. W. Esposito, E. R. Stofan and T. E. Cravens), American Geophysical Union, Washington, D. C.. doi: 10.1029/176GM07

● Schubert , G. (1983), General circulation and the dynamical state of the Venus atmosphere, in Venus, edited by D. Hunten, L. Colin, T. Donahue, and V. Moroz, pp. 681–765, University of Arizona Press, Tucson.

● Thompson, R. (1970), Venus’ general circulation is a merry-go-round, J. Atmos. Sci., 27, 1107–1116.● Yamamoto, M., and M. Takahashi (2006a), Superrotation maintained by meridional circulation and waves in a Venus-like AGCM, J. Atmos. Sci.,

63, 3296–3314.● Young, R. E., and J. B. Pollack (1977), A three-dimensional model of dynamical processes in the Venus atmosphere, J. Atmos. Sci., 34, 1315–

1351. Young, R. E., and J. B. Pollack (1980), Reply, J. Atmos. Sci., 37, 253–254. Young, R. E., A. P. Ingersoll, D. Crisp, L. S. Elson, R. A. Preston, R. L. Walterscheid, G. Schubert , G. S. Golitsyn, J. E. Blamont, V. N. Ivarov, R. S. Sagdeev, V. M. Linkin, and V. V. Kerzhanovich (1987), Implications of the VEGA balloon results for Venus atmospheric dynamics, Adv. Space Res., 7, (12)303–(12)305.

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