,,- CNRS, LMD, Sorbonne University, Paris, France (eran.vos@gmail.com)
Mars has several ice deposits; the North Polar Layered Deposits attract the most interest due to many exposures of a stratigraphy of alternating layers. These layers are believed to indicate variations in polar ice/dust accumulation rate. [1, 2]. At present, surface ice is stable only in the polar regions. But there are remnants of glaciers in the tropics and mid-latitudes. The NPLD dust-rich layers are formed either at low levels of ice accumulation or by sublimation, leaving behind lag layers. During the last 5 Myr, Mars’ obliquity value has varied between 45◦ and 15◦ [3], leading to a significant change in insolation and, as a result, migration of ice. Higher obliquity values lead to NPLD loss, while lower values lead to accumulation, given that a source is present.
Here, we calculate the migration of ice from (to) the NPLD as the obliquity rises (decreases) for a full obliquity cycle (120 kyr), starting at present-day to 45◦ and back to 25◦, using a new approach, asynchronous coupling between the Mars Planetary Climate Model (PCM) [4] and the Planetary Evolution Model (PEM) [5], which smartly extrapolates the tendencies from the PCM. This long 120 kyr simulation is possible due to our latest model developments of the subsurface ice scheme [6] in the Planetary Climate Model and the development of the Planetary Evolution Model [5]
References:
[1] Hvidberg, C. et al. Reading the climate record of the martian polar layered deposits. Icarus 221, 405–419 (2012).
[2] Vos, E., Aharonson, O. & Schorghofer, N. Icarus 324, 1–7 (2019).
[3] Laskar, J. et al. Astron. Astrophys. 428, 261–285 (2004).
[4] Forget, F. et al. J. Geophys. Res. Planets 104 (1999).
[5] Clement, J.-B. et al. A New Long-Term Planetary Evolution Model to Simulate the Formation of Polar Layered Deposits on Mars in 8th International Conference on Mars Polar Science and Exploration (2024), LPI–Contribution.
[6] Vos, E., Forget, F., Cl´ement, J.-B., Lange, L. & Millour, E. The Martian Mid-Latitude Subsurface Ice is the remnant of a past ice sheet.
How to cite: Vos, E., Forget, F., Clement, J., Lange, L., and Millour, E.: A 120,000-year simulation of Mars undergoing an obliquity cycle up to 45◦ and back, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-1566, https://doi.org/10.5194/epsc-dps2025-1566, 2025.
