Solar occultation spectroscopic measurements of the martian atmosphere at 1.9 and 3.7 μm

WE present solar occultation measurements, taken from Phobos 2, of the H2O and CO2 bands at 1.9 μm and of the dust absorption at 1.9 and 3.7 μin. From these, we have calculated vertical profiles of water vapour, dust and atmosphere temperature in the range of 10–70 km. The water-vapour mixing-ratio profile demonstrates oscillations from 10-5 to 10-3 with a period of 25 km. We explain this behaviour by the condensation and evaporation of water at minima and maxima of the temperature oscillations.