Evolution of water vapor vertical distribution during a Martian year with SPICAM/Mars Express solar occultations

Observations of the water vapor vertical distribution in the atmosphere of Mars are essential to constrain the various physical processes that drive the water cycle on the planet. The SPICAM spectrometer on Mars Express retrieves by far the most extensive dataset currently available through solar occultations. We will present here the first monitoring ever of the seasonal variations of the H2O vertical profile in the Martian atmosphere. We will focus mainly on Martian Year 29 (MY29) data. Results exhibit a significant difference with the General Circulation Model (GCM) predictions. We show that the interactions between the dust and water climatic cycles are stronger than expected.