Abstract
The nature of the martian south polar cap has remained enigmatic since the first spacecraft observations1,2,3,4,5,6. In particular, the presence of a perennial carbon dioxide ice cap, the formation of a vast area of black ‘slab ice’ known as the Cryptic region and the asymmetric springtime retreat of the cap have eluded explanation. Here we present observations and climate modelling that indicate the south pole of Mars is characterized by two distinct regional climates that are the result of dynamical forcing by the largest southern impact basins, Argyre and Hellas. The style of surface frost deposition is controlled by these regional climates. In the cold and stormy conditions that exist poleward of 60° S and extend 180° in longitude west from the Mountains of Mitchel (∼ 30° W), surface frost accumulation is dominated by precipitation. In the opposite hemisphere, the polar atmosphere is relatively warm and clear and frost accumulation is dominated by direct vapour deposition. It is the differences in these deposition styles that determine the cap albedo.
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
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout



References
Leighton, R. L. & Murray, B. C. Behaviour of carbon dioxide and other volatiles on Mars. Science 153, 136–144 (1966)
Paige, D. A. & Ingersoll, A. P. Annual heat balance of Martian polar caps Viking observations. Science 228, 1160–1168 (1985)
Lindner, B. L. The hemispherical asymmetry in the Martian polar caps. J. Geophys. Res. 98, 3339–3344 (1993)
James, P. B. et al. Seasonal recession of Martian South Polar Cap; 1992 HST observations. Icarus 123, 87–100 (1996)
Kieffer, H. H., Titus, T. N., Mullins, K. F. & Christensen, P. R. Mars south polar spring and summer behaviour observed by TES: Seasonal cap evolution controlled by frost grain size. J. Geophys. Res. 105, 9653–9700 (2000)
Thomas, P. C. et al. North–south geological differences between the residual polar caps on Mars. Nature 404, 161–164 (2000)
Forget, F., Hourdin, F. & Talagrand, O. CO2 snowfall on Mars: Simulation with a general circulation model. Icarus 131, 302–316 (1998)
Titus, T. N., Kieffer, H. H., Mullins, K. F. & Christensen, P. R. TES premapping data: Slab ice and snow flurries in the Martian north polar night. J. Geophys. Res. 106, 23181–23196 (2001)
Pettengill, G. H. & Ford, P. G. Winter clouds over the north Martian polar cap. Geophys. Res. Lett. 27, 609–613 (2001)
Ivanov, A. B. & Muhleman, D. O. Cloud reflection observations: results from the Mars Orbiter Laser Altimeter. Icarus 154, 190–206 (2001)
Colaprete, A. & Toon, O. B. Carbon dioxide snow storms during the polar night on Mars. J. Geophys. Res. 107, doi:10.1029/2001JE001758 (2002)
Colaprete, A., Haberle, R. M. & Toon, O. B. Formation of convective carbon dioxide clouds near the south pole of Mars. J. Geophys. Res. 108, doi:10.1029/2003JE002053 (2003)
Hinson, D. P., Wilson, R. J., Smith, M. D. & Conrath, B. J. Stationary planetary waves in the atmosphere of Mars during southern winter. J. Geophys. Res. 108, doi:10.1029/2002JE001949 (2003)
Hinson, D. P. & Wilson, R. J. Transient eddies in the Southern Hemisphere of Mars. Geophys. Res. Lett. 29, doi:10.1029/2001GL014103 (2002)
Haberle, R. M. et al. General circulation model simulations of the Mars Pathfinder atmospheric structure investigation/meteorology data. J. Geophys. Res. 104, 8957–8974 (1999)
Colaprete, A. & Toon, O. B. Carbon dioxide clouds in an early dense Martian atmosphere. J. Geophys. Res. 108, doi:10.1029/2002JE001967 (2003)
Holton, J. R. An Introduction to Dynamic Meteorology 3rd edn (Academic, London, 1992)
Hollingsworth, J. L. & Barnes, J. R. Forced, stationary planetary waves in Mars' winter atmosphere. J. Atmos. Sci. 53, 428–448 (1996)
Banfield, D., Conrath, B. J., Smith, M. D., Christensen, P. R. & Wilson, R. J. Forced waves in the Martian atmosphere from MGS TES nadir data. Icarus 161, 319–345 (2003)
Jakosky, B. M. & Haberle, R. M. Year-to-year instability of the Mars south polar cap. J. Geophys. Res. 95, 1359–1365 (1990)
Malin, M. C., Caplinger, M. A. & Davis, S. D. Observational evidence for an active surface reservoir of solid carbon dioxide on Mars. Science 294, 2146–2148 (2001)
Byrne, S. & Ingersoll, A. P. A sublimation model for Martian south polar ice features. Science 299, 1051–1053 (2003)
Byrne, S. & Ingersoll, A. P. Martian climate events on timescales of centuries: Evidence from feature morphology in the residual south polar ice cap. Geophys. Res. Lett. 30, doi:10.1029/2003GL017597 (2003)
Acknowledgements
We acknowledge discussions with F. Montmessin and F. Forget. This work was supported under NASA's Planetary Atmospheres Program.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare that they have no competing financial interests.
Rights and permissions
About this article
Cite this article
Colaprete, A., Barnes, J., Haberle, R. et al. Albedo of the south pole on Mars determined by topographic forcing of atmosphere dynamics. Nature 435, 184–188 (2005). https://doi.org/10.1038/nature03561
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature03561
This article is cited by
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.