The sublimation and condensation processes of the seasonal Martian caps are linked to the CO2 cycle, the main cycle on Mars. Observing the seasonal growth/recession rates of the caps provides insight into the local and global environment. These seasonal processes strongly influence the global energy budget of Mars. While they are repeatable throughout the Martian Years (MY), interannual variability exists due to global dust storms. These storms also affect the water cycle and atmospheric escape.

Since April 2018, the Nadir and Occultation for Mars Discovery (NOMAD) instrument on board ExoMars-Trace Gas Orbiter has been monitoring the Martian atmosphere. Although NOMAD is not primarily dedicated to surface analysis, this PhD thesis develops high spectral resolution methods to analyse the information content of NOMAD's nadir infrared channel (2.3-3.8 µm) for surface information. By identifying ice absorption bands in this spectral range, spectral indices are defined to distinguish CO2 ice from H2O ice. The research compares seasonal processes in the Martian caps during MY34-36 (April 2018 to December 2022), and analyses the potential impact of the MY34 global dust storm on the Southern polar cap. In addition, the present thesis demonstrates that NOMAD is also able to detect atmospheric ice signatures, such as the Polar Hood clouds (H2O ice clouds) at high latitudes and mesospheric CO2 ice clouds at mid-equatorial latitudes. Finally, the high spectral resolution of NOMAD offers the possibility to retrieve some microphysical ice properties.