12:00 PM - 12:15 PM
[PPS05-06] The evolution of redox gradients on Mars in space and time
Keywords:Mars, Astrobiology, Landing Sites
We use time-dependent geodynamic models, capable of computing the 3D temperature profile and self-consistently accounting for serpentinization and radiolysis reactions as a function of subsurface temperature, pressure, and chemistry throughout the last 4.5 billion years (based on -). Additionally, we couple a parameterized climate model, which computes the local average annual surface temperature and pressure varying with obliquity and has been gauged with the Mars Weather Research and Forecasting (MarsWRF) GCM. MarsWRF is a global model based on the terrestrial mesoscale WRF model (see -) and is a Mars-specific implementation of the PlanetWRF GCM .
Geodynamic and climate models combined allow us to compute for Mars the time-dependent 3D distribution of 1) hydrogen-rich reducing subsurface environments, driven by serpentinization and radiolysis of water, and 2) oxygen-rich regions as a product of atmosphere-brine interactions governed by climate and surface chemistry. We will show spatial maps of such zones and results on their variability in the last 20 Myr and discuss implications for life, planetary protection, and landing site selection on Mars.
References.  Stamenkovic, V., Noack, L., Breuer, D., Spohn, T. (2012) The Astrophysical Journal, 748, 41-63.  Stamenkovic, V. (2015) In: Gargaud, M., et al. (Eds.) Encyclopedia of Astrobiology, Part 19. Springer, 1505-1506.  Stamenkovic, V., Höink, T., Lenardic, T. (2016) JGR Planets, 121, 1–20.  Stamenkovic, V., Seager, S. (2016), The Astrophysical Journal, 825, 78-95.  Michalakes, J., J. Dudhia, D. Gill, T. Henderson, J. Klemp, W. Skamarock, and W. Wang (2004) Proceedings of the 11th ECMWF Workshop on the Use of High Performance Computing In Meteorology, edited by G. Mozdzynski, 156–168.  Skamarock, W. C., J. B. Klemp, J. Dudhia, D. O. Gill, D. M. Barker, W. Wang, and J. G. Powers (2005) NCAR Tech. Note 468+STR, Natl. Cent. for Atmos. Res., Boulder, Colo.  Skamarock, W. C., and J. B. Klemp (2008) J. Comp. Phys., 227, 3465–3485.  Richardson, M. I., A. D. Toigo, and C. E. Newman (2007) J. Geophys. Res., 112.
Additional Information. This work has been supported through a “Simons Collaboration on the Origins of Life” fellowship (338555, VS).