ISSI working team:

Water in Mars atmosphere: Comparison of Recent Data Sets

Team leader: Oleg Korablev, Space Research Institute (IKI), Moscow

Jean-Loup Bertaux
Vittorio Formisano
Michael D. Smith
Theirry Fouchet
Dmitry Titov
Emmanuel Lellouch
Ludmila Zasova
Nikolai Ignatiev
Anna Fedorova
Franck Montmessin
Sasha Rodin
Ann Sprague
R. Todd Clancy
Therese Encrenaz
Davide Grassi

PhD students
    Severine Perrier
    Martin Tschimmel
    Luca Maltagliati 


Atmospheric water cycle is a significant component of the Martian climate, which is believed to be in large extent responsible for such features of the Martian surface as the asymmetry of polar caps, equatorial anomalies of hydrogen content in the regolith and peculiar morphology of the slopes of major volcanoes. A crucial insight into the Martian water cycle may be provided by its detailed characterization in its current state. Mars Express, a versatile atmospheric mission, carries three instruments capable to measure atmospheric water vapour from near-IR to thermal IR spectral ranges. PFS covers both spectral ranges, SPICAM IR measures in near-IR, and OMEGA contributes to the subject with spatially resolved measurements in the near-IR, which need to be validated with the data of two other experiments. Comparisons of data on the first Mars Express conference at ESTEC showed a substantial disagreement among these data sets. We intend to seek in detail the origin of the apparent disagreement, and to understand the information present in the different water vapour bands measured by different instruments. The data will be compared with MGS simultaneous measurements (taken in thermal-IR), and with ground-based monitoring sequences (microwave, near-IR).   As a result we intend to introduce necessary corrections into the retrieval techniques used, build the MEX H2O climatology, and to relate it to the most complete to date MGS climatology, and to available measurements in the near IR obtained in Viking epoch. The measurements will be compared to the most advanced Mars Global Circulation Models involving water cycle, for improvements of these models, and for interpolation of data into space and time domain where observations are unavailable.