Publication Date:
2023-01-14
Description:
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.
Description:
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 metamorphism of the seasonal deposits and phased snowfall. The maximum volume of the SNPC is constrained to be 9.6 × 1012 m3. The bulk density of the SNPC does not continuously increase as previously assumed but can go through phased decreases in accordance with phased snowfall at the north pole. These findings can put important constraints on the Martian climate models.
Description:
Key Points:
Through co‐registration of laser altimetry profiles, spatio‐temporal level variations of the Seasonal North Polar Cap (SNPC) of Mars are obtained.
Maximum level of the SNPC can be up to 3.8 m at Olympia Undae and up to 1.3 m over the Residual North Polar Cap.
Northern winter decreases of up to 3 m and northern spring increases of up to 2 m are observed at Olympia Undae.
Description:
China Scholarship Council
Description:
Deutsche Forschungsgemeinschaft
Description:
Institut National des Sciences de l’Univers
Description:
Centre National de la Recherche Scientifique
Description:
Centre National d’Etudes Spatiales
Description:
https://doi.org/10.17632/x953mzxxvv.1
Description:
https://doi.org/10.17632/z59b9nd6s9.2
Description:
https://pds-geosciences.wustl.edu/missions/mgs/pedr.html
Description:
https://naif.jpl.nasa.gov/pub/naif/pds/data/mgs-m-spice-6-v1.0/mgsp_1000/data/
Description:
https://www.uahirise.org/hiwish/browse
Keywords:
ddc:523
;
Mars
;
seasonal polar cap
;
CO2 ice
;
MOLA
;
level variation
;
pseudo cross‐over
Language:
English
Type:
doc-type:article
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