Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice
International audience Observations of the Martian CO ice cap in late winter and spring have revealed exotic phenomena. Unusual dark spots, fans and blotches form as the south-polar seasonal CO ice cap retreats. The formation mechanisms of these features are not clearly understood. Theoretical model...
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ftecoleponts:oai:HAL:hal-00743841v1 2024-06-09T07:46:41+00:00 Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice Pilorget, C. Forget, F. Millour, E. Vincendon, M. Madeleine, J.B. Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) Department of Geological Sciences Providence Brown University 2011-04-21 https://hal.science/hal-00743841 https://hal.science/hal-00743841/document https://hal.science/hal-00743841/file/PEER_stage2_10.1016%252Fj.icarus.2011.01.031.pdf https://doi.org/10.1016/j.icarus.2011.01.031 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.icarus.2011.01.031 hal-00743841 https://hal.science/hal-00743841 https://hal.science/hal-00743841/document https://hal.science/hal-00743841/file/PEER_stage2_10.1016%252Fj.icarus.2011.01.031.pdf doi:10.1016/j.icarus.2011.01.031 info:eu-repo/semantics/OpenAccess ISSN: 0019-1035 EISSN: 1090-2643 Icarus https://hal.science/hal-00743841 Icarus, 2011, ⟨10.1016/j.icarus.2011.01.031⟩ Mars polar caps climate ices [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2011 ftecoleponts https://doi.org/10.1016/j.icarus.2011.01.031 2024-05-16T11:42:08Z International audience Observations of the Martian CO ice cap in late winter and spring have revealed exotic phenomena. Unusual dark spots, fans and blotches form as the south-polar seasonal CO ice cap retreats. The formation mechanisms of these features are not clearly understood. Theoretical models suggest that photons could penetrate deep into the CO ice down to the regolith, leading to basal sublimation and gas and dust ejection. We have developed a detailed thermal model able to simulate the temporal evolution of the regolith-CO ice layer-atmosphere column. It takes into account heat conduction, radiative transfer within the ice and the atmosphere, and latent heat exchange when there is a phase transition. We found that a specific algorithm, fully coupling these 3 components, was needed to properly predict ice sublimation below the surface. Our model allows us to determine under what conditions basal sublimation is possible and thus when and where it can occur on Mars. Our results show that basal sublimation is possible if we consider large pathlengths and very little dust content within the ice. Moreover, the model can explain how dark spots can appear very early after the end of the polar night at high latitudes. We also evaluate the importance of the different parameters in our simulations. Contrary to what was suggested by theoretical models, the role of seasonal thermal waves is found to be limited. Solar radiation alone can initiate basal sublimation, which therefore only depends on the CO ice properties. Three main modes were identified: one where condensation/sublimation only occurs at the surface (in the case of small grains and/or high dust content), one where basal sublimation is possible (large pathlengths and very little dust content) and an intermediate mode where sublimation within the ice may occur. We suggest that these different modes could be keys to understanding many processes that occur at the surface of Mars, like the anticryptic area behavior or the recent reported activity in ... Article in Journal/Newspaper Ice cap polar night École des Ponts ParisTech: HAL Icarus 213 1 131 149 |
institution |
Open Polar |
collection |
École des Ponts ParisTech: HAL |
op_collection_id |
ftecoleponts |
language |
English |
topic |
Mars polar caps climate ices [SDU]Sciences of the Universe [physics] |
spellingShingle |
Mars polar caps climate ices [SDU]Sciences of the Universe [physics] Pilorget, C. Forget, F. Millour, E. Vincendon, M. Madeleine, J.B. Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
topic_facet |
Mars polar caps climate ices [SDU]Sciences of the Universe [physics] |
description |
International audience Observations of the Martian CO ice cap in late winter and spring have revealed exotic phenomena. Unusual dark spots, fans and blotches form as the south-polar seasonal CO ice cap retreats. The formation mechanisms of these features are not clearly understood. Theoretical models suggest that photons could penetrate deep into the CO ice down to the regolith, leading to basal sublimation and gas and dust ejection. We have developed a detailed thermal model able to simulate the temporal evolution of the regolith-CO ice layer-atmosphere column. It takes into account heat conduction, radiative transfer within the ice and the atmosphere, and latent heat exchange when there is a phase transition. We found that a specific algorithm, fully coupling these 3 components, was needed to properly predict ice sublimation below the surface. Our model allows us to determine under what conditions basal sublimation is possible and thus when and where it can occur on Mars. Our results show that basal sublimation is possible if we consider large pathlengths and very little dust content within the ice. Moreover, the model can explain how dark spots can appear very early after the end of the polar night at high latitudes. We also evaluate the importance of the different parameters in our simulations. Contrary to what was suggested by theoretical models, the role of seasonal thermal waves is found to be limited. Solar radiation alone can initiate basal sublimation, which therefore only depends on the CO ice properties. Three main modes were identified: one where condensation/sublimation only occurs at the surface (in the case of small grains and/or high dust content), one where basal sublimation is possible (large pathlengths and very little dust content) and an intermediate mode where sublimation within the ice may occur. We suggest that these different modes could be keys to understanding many processes that occur at the surface of Mars, like the anticryptic area behavior or the recent reported activity in ... |
author2 |
Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) Department of Geological Sciences Providence Brown University |
format |
Article in Journal/Newspaper |
author |
Pilorget, C. Forget, F. Millour, E. Vincendon, M. Madeleine, J.B. |
author_facet |
Pilorget, C. Forget, F. Millour, E. Vincendon, M. Madeleine, J.B. |
author_sort |
Pilorget, C. |
title |
Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
title_short |
Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
title_full |
Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
title_fullStr |
Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
title_full_unstemmed |
Dark spots and cold jets in the polar regions of Mars: new clues from a thermal model of surface CO ice |
title_sort |
dark spots and cold jets in the polar regions of mars: new clues from a thermal model of surface co ice |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://hal.science/hal-00743841 https://hal.science/hal-00743841/document https://hal.science/hal-00743841/file/PEER_stage2_10.1016%252Fj.icarus.2011.01.031.pdf https://doi.org/10.1016/j.icarus.2011.01.031 |
genre |
Ice cap polar night |
genre_facet |
Ice cap polar night |
op_source |
ISSN: 0019-1035 EISSN: 1090-2643 Icarus https://hal.science/hal-00743841 Icarus, 2011, ⟨10.1016/j.icarus.2011.01.031⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.icarus.2011.01.031 hal-00743841 https://hal.science/hal-00743841 https://hal.science/hal-00743841/document https://hal.science/hal-00743841/file/PEER_stage2_10.1016%252Fj.icarus.2011.01.031.pdf doi:10.1016/j.icarus.2011.01.031 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1016/j.icarus.2011.01.031 |
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