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.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
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)
We acknowledge discussions with F. Montmessin and F. Forget. This work was supported under NASA's Planetary Atmospheres Program.
The authors declare that they have no competing financial interests.
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
Asymmetries in Snowfall, Emissivity, and Albedo of Mars' Seasonal Polar Caps: Mars Climate Sounder Observations
Journal of Geophysical Research: Planets (2020)
The Holy Grail: A road map for unlocking the climate record stored within Mars’ polar layered deposits
Planetary and Space Science (2020)
Southern Martian winter weather associated with baroclinic topography forced Rossby waves: analysing by Global Mars Multiscale Model
Astrophysics and Space Science (2019)
6th international conference on Mars polar science and exploration: Conference summary and five top questions
Modification history of the Harmakhis Vallis outflow channel, Mars, based on CTX-scale photogeologic mapping and crater count dating