EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Diurnal and Seasonal Mapping of Martian Ices with EMM/EMIRS

Aurélien Stcherbinine1, Christopher Edwards1, Michael Wolff2, Eman Altunaiji3, Christopher Haberle1, Michael Smith4, and Philip Christensen5
Aurélien Stcherbinine et al.
  • 1Northern Arizona University, Flagstaff, USA (
  • 2Space Science Institute, Boulder, USA
  • 3Mohammed Bin Rashid Space Centre, Dubai, UAE
  • 4NASA Goddard Space Flight Center, Greenbelt, USA
  • 5Arizona State University, Phoenix, USA

Condensation and sublimation of ices at the surface of the planet is a key part of both the Martian H2O and CO2 cycles, either from a seasonal or diurnal aspect. If most of the ices are located within the polar caps, surface frost is known to be formed during nighttime down to equatorial latitudes. The Emirate Mars InfraRed Spectrometer (EMIRS) instrument onboard the Emirates Mars Mission (EMM) "Hope" probe is a Fourier Transform Infrared spectrometer that is observing the Martian surface and atmosphere between 6 and 100 μm from February 2022. The unique orbit of EMM allows EMIRS to observe the entire Martian disk at each observation, covering all the surface of the planet across all local times in ~ 4 orbits, which corresponds to ~ 5° of Ls.

Here we use the surface temperature data retrieved from the EMIRS spectra (Smith et al. 2022) to detect and map the ice at the surface of the Red Planet. We compute the amplitude of the diurnal temperature variations to derive maps of the presence of ices (either H2O or CO2) at the surface of the planet over the day, which allows us to monitor the seasonal evolution of the polar caps. And, based on the methodology used in Piqueux et al. (2016), we also compute for each EMIRS pixel the corresponding freezing temperature of CO2, according to Clapeyron’s law, and we consider that CO2 ice is present at the surface if the retrieved temperature is below TCO2, ice. This allows us to monitor the timing of the formation and disappearance of the surface CO2 frost under midlatitudes over the Martian night, and its seasonal evolution.

How to cite: Stcherbinine, A., Edwards, C., Wolff, M., Altunaiji, E., Haberle, C., Smith, M., and Christensen, P.: Diurnal and Seasonal Mapping of Martian Ices with EMM/EMIRS, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9770,, 2023.