Albedo control of seasonal south polar cap recession on Mars
Abstract Over the last few decades, General Circulation Models (GCM) have been used to simulate the current Martian climate. The calibration of these GCMs with the current seasonal cycle is a crucial step in understanding the climate history of Mars. One of the main climatic signals currently used t...
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fttrinitycoll:oai:tara.tcd.ie:2262/43255 2023-05-15T18:23:25+02:00 Albedo control of seasonal south polar cap recession on Mars 2010-12-14T18:29:03Z http://hdl.handle.net/2262/43255 https://doi.org/10.1016/j.icarus.2008.12.014 en eng Elsevier 00191035 (ISSN) S0019-1035(08)00435-1 (PII) S0019-1035(08)00435-1 (publisherID) http://hdl.handle.net/2262/43255 Icarus 200 2 374 doi:10.1016/j.icarus.2008.12.014 2008 18 months Marssurface Marspolar caps Ice Spectroscopy 2010 fttrinitycoll https://doi.org/10.1016/j.icarus.2008.12.014 2020-02-16T13:49:40Z Abstract Over the last few decades, General Circulation Models (GCM) have been used to simulate the current Martian climate. The calibration of these GCMs with the current seasonal cycle is a crucial step in understanding the climate history of Mars. One of the main climatic signals currently used to validate GCMs is the annual atmospheric pressure cycle. It is difficult to use changes in seasonal deposits on the surface of Mars to calibrate the GCMs given the spectral ambiguities between CO2 and H2O ice in the visible range. With the OMEGA imaging spectrometer covering the near infra-red range, it is now possible to monitor both types of ice at a spatial resolution of about 1 km. At global scale, we determine the change with time of the Seasonal South Polar Cap (SSPC) crocus line, defining the edge of CO2 deposits. This crocus line is not symmetric around the geographic South Pole. At local scale, we introduce the snowdrop distance, describing the local structure of the SSPC edge. Crocus line and snowdrop distance changes can now be used to calibrate GCMs. The albedo of the seasonal deposits is usually assumed to be a uniform and constant parameter of the GCMs. In this study, albedo is found to be the main parameter controlling the SSPC recession at both global and local scale. Using a defrost mass balance model (referred to as D-frost) that incorporates the effect of shadowing induced by topography, we show that the global SSPC asymmetry in the crocus line is controlled by albedo variations. At local scale, we show that the snowdrop distance is correlated with the albedo variability. Further GCM improvements should take into account these two results. We propose several possibilities for the origin of the asymmetric albedo control. The next step will be to identify and model the physical processes that create the albedo differences. correspondance: Corresponding author. Tel.: +34 91 81 31 421; fax: +34 91 81 31 325 (Schmidt, Frederic) fschmidt@sciops.esa.int (Schmidt, Frederic) sylvain.doute@obs.ujf-grenoble.fr (Doute, Sylvain) ESA - ESAC--> , PO Box 78--> , E-28691 VILLANUEVA DE LA CA?ADA MADRID--> - SPAIN (Schmidt, Frederic) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Schmidt, Frederic) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Doute, Sylvain) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Schmitt, Bernard) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Vincendon, Mathieu) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Bibring, Jean-Pierre) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Lanvevin, Yves) FRANCE SPAIN Received: 2007-12-19 Revised: 2008-10-09 Accepted: 2008-12-01 Other/Unknown Material South pole The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) Mathieu ENVELOPE(136.814,136.814,-66.331,-66.331) Red Range ENVELOPE(-134.054,-134.054,60.049,60.049) South Pole Villanueva ENVELOPE(-61.733,-61.733,-66.200,-66.200) Icarus 200 2 374 394 |
institution |
Open Polar |
collection |
The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) |
op_collection_id |
fttrinitycoll |
language |
English |
topic |
Marssurface Marspolar caps Ice Spectroscopy |
spellingShingle |
Marssurface Marspolar caps Ice Spectroscopy Albedo control of seasonal south polar cap recession on Mars |
topic_facet |
Marssurface Marspolar caps Ice Spectroscopy |
description |
Abstract Over the last few decades, General Circulation Models (GCM) have been used to simulate the current Martian climate. The calibration of these GCMs with the current seasonal cycle is a crucial step in understanding the climate history of Mars. One of the main climatic signals currently used to validate GCMs is the annual atmospheric pressure cycle. It is difficult to use changes in seasonal deposits on the surface of Mars to calibrate the GCMs given the spectral ambiguities between CO2 and H2O ice in the visible range. With the OMEGA imaging spectrometer covering the near infra-red range, it is now possible to monitor both types of ice at a spatial resolution of about 1 km. At global scale, we determine the change with time of the Seasonal South Polar Cap (SSPC) crocus line, defining the edge of CO2 deposits. This crocus line is not symmetric around the geographic South Pole. At local scale, we introduce the snowdrop distance, describing the local structure of the SSPC edge. Crocus line and snowdrop distance changes can now be used to calibrate GCMs. The albedo of the seasonal deposits is usually assumed to be a uniform and constant parameter of the GCMs. In this study, albedo is found to be the main parameter controlling the SSPC recession at both global and local scale. Using a defrost mass balance model (referred to as D-frost) that incorporates the effect of shadowing induced by topography, we show that the global SSPC asymmetry in the crocus line is controlled by albedo variations. At local scale, we show that the snowdrop distance is correlated with the albedo variability. Further GCM improvements should take into account these two results. We propose several possibilities for the origin of the asymmetric albedo control. The next step will be to identify and model the physical processes that create the albedo differences. correspondance: Corresponding author. Tel.: +34 91 81 31 421; fax: +34 91 81 31 325 (Schmidt, Frederic) fschmidt@sciops.esa.int (Schmidt, Frederic) sylvain.doute@obs.ujf-grenoble.fr (Doute, Sylvain) ESA - ESAC--> , PO Box 78--> , E-28691 VILLANUEVA DE LA CA?ADA MADRID--> - SPAIN (Schmidt, Frederic) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Schmidt, Frederic) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Doute, Sylvain) Laboratoire de Planetologie de Grenoble--> , Universite de Grenoble--> , CNRS--> , INSU--> , BP 53--> , 38041 Grenoble Cedex 9--> - FRANCE (Schmitt, Bernard) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Vincendon, Mathieu) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Bibring, Jean-Pierre) Institut d'Astrophysique Spatiale--> , Universite Paris XI--> , Batiment 121--> , 91405 Orsay cedex--> - FRANCE (Lanvevin, Yves) FRANCE SPAIN Received: 2007-12-19 Revised: 2008-10-09 Accepted: 2008-12-01 |
title |
Albedo control of seasonal south polar cap recession on Mars |
title_short |
Albedo control of seasonal south polar cap recession on Mars |
title_full |
Albedo control of seasonal south polar cap recession on Mars |
title_fullStr |
Albedo control of seasonal south polar cap recession on Mars |
title_full_unstemmed |
Albedo control of seasonal south polar cap recession on Mars |
title_sort |
albedo control of seasonal south polar cap recession on mars |
publisher |
Elsevier |
publishDate |
2010 |
url |
http://hdl.handle.net/2262/43255 https://doi.org/10.1016/j.icarus.2008.12.014 |
long_lat |
ENVELOPE(136.814,136.814,-66.331,-66.331) ENVELOPE(-134.054,-134.054,60.049,60.049) ENVELOPE(-61.733,-61.733,-66.200,-66.200) |
geographic |
Mathieu Red Range South Pole Villanueva |
geographic_facet |
Mathieu Red Range South Pole Villanueva |
genre |
South pole |
genre_facet |
South pole |
op_relation |
00191035 (ISSN) S0019-1035(08)00435-1 (PII) S0019-1035(08)00435-1 (publisherID) http://hdl.handle.net/2262/43255 Icarus 200 2 374 doi:10.1016/j.icarus.2008.12.014 |
op_rights |
2008 18 months |
op_doi |
https://doi.org/10.1016/j.icarus.2008.12.014 |
container_title |
Icarus |
container_volume |
200 |
container_issue |
2 |
container_start_page |
374 |
op_container_end_page |
394 |
_version_ |
1766202999610277888 |