Open AccessOn the mystery of the perennial carbon dioxide cap at the south pole of Mars
Author(s) -
Guo Xin,
Richardson Mark Ian,
Soto Alejandro,
Toigo Anthony
Publication year - 2010
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009je003382
Subject(s) - albedo (alchemy) , mars exploration program , atmospheric sciences , environmental science , northern hemisphere , martian , ice albedo feedback , geology , sea ice , cryosphere , climatology , sea ice thickness , astrobiology , physics , art , performance art , art history
A perennial ice cap has long been observed near the south pole of Mars. The surface of this cap is predominantly composed of carbon dioxide ice. The retention of a CO 2 ice cap results from the surface energy balance of the latent heat, solar radiation, surface emission, subsurface conduction, and atmospheric sensible heat. While models conventionally treat surface CO 2 ice using constant ice albedos and emissivities, such an approach fails to predict the existence of a perennial cap. Here we explore the role of the insolation‐dependent ice albedo, which agrees well with Viking, Mars Global Surveyor, and Mars Express albedo observations. Using a simple parameterization within a general circulation model, in which the albedo of CO 2 ice responds linearly to the incident solar insolation, we are able to predict the existence of a perennial CO 2 cap at the observed latitude and only in the southern hemisphere. Further experiments with different total CO 2 inventories, planetary obliquities, and surface boundary conditions suggest that the location of the residual cap may exchange hemispheres favoring the pole with the highest peak insolation.