Spatio‐Temporal Level Variations of the Martian Seasonal North Polar Cap From Co‐Registration of MOLA Profiles

• Published in: Journal of Geophysical Research: Planets
• Main Authors: Xiao, Haifeng, Stark, Alexander, Schmidt, Frédéric, Hao, Jingyan, Steinbrügge, Gregor, Wagner, Nicholas L., Su, Shu, Cheng, Yuan, Oberst, Jürgen, Stark, Alexander; 2 Institute of Planetary Research German Aerospace Center (DLR) Berlin Germany, Schmidt, Frédéric; 3 Université Paris‐Saclay CNRS GEOPS Orsay France, Hao, Jingyan; 5 Division of Space Technology Luleå University of Technology Kiruna Space Campus Norrbotten County Sweden, Steinbrügge, Gregor; 7 Department of Geophysics Stanford University Stanford CA USA, Wagner, Nicholas L.; 8 Department of Geosciences Baylor University Waco TX USA, Cheng, Yuan; 9 College of Surveying and Geo‐Informatics Tongji University Shanghai China, Oberst, Jürgen; 1 Institute of Geodesy and Geoinformation Science Technische Universität Berlin Berlin Germany
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: ddc:523; Mars; seasonal polar cap; CO2 ice; MOLA; level variation; pseudo cross‐over; South Pole; South pole
• Online Access: https://doi.org/10.1029/2021JE007158; http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10391

The seasonal deposition and sublimation of CO2 constitute a major element in Martian volatile cycles. We reprocess the Mars Orbiter Laser Altimeter (MOLA) data and apply co‐registration procedures to obtain spatio‐temporal variations in levels of the Seasonal North Polar Cap (SNPC). The maximum level over the Residual North Polar Cap (RNPC) is 1.3 m, approximately half of that at the south pole (2.5 m). However, the maximum level in the dune fields at Olympia Undae can be up to 3.8 m. Furthermore, off‐season decreases up to 3 m during the northern winter at Olympia Undae are observed. These are likely due to metamorphism effects accentuated by the reduced snowfall at this period. Meanwhile, off‐season increases of up to 2 m during the northern spring are noted, the cause of which remains to be explored. The volume of the SNPC peaks at the end of northern winter and is estimated to be approximately 9.6 × 1012 m3, which is 2% more than that of the Seasonal South Polar Cap. The bulk density of the SNPC can go through phased decreases in accordance with phased accumulation at northern high‐latitudes. These findings can put important constraints on the Martian volatile cycling models. Plain Language Summary: Due to its axial tilt, seasons also exist on Mars. Up to one third of the atmosphere's CO2 is in annual exchange with the polar regions through seasonal deposition/sublimation processes. Here, we make use of previously proposed approaches of analyzing the Mars Orbiter Laser Altimeter profiles and obtain spatio‐temporal level variations of the Seasonal North Polar Cap (SNPC). Particularly, we bring attention to abnormal behavior of the SNPC in the dune fields at Olympia Undae. Maximum level there can be all the way up to 4 m which is much higher than a maximum of 1.5 m over the Residual North Polar Cap. Meanwhile, off‐season decreases during the northern winter with magnitudes up to 3 m and off‐season increases during the northern spring of magnitudes up to 2 m are observed. These could possibly be related to ...