The Atmosphere of Mars as Constrained by Remote Sensing

In addition to the Viking in-situ mass spectrometry measurements, our knowledge of the Martian atmosphere comes from remote sensing spectroscopy from the ground and from space. In particular, infrared measurements from the Mariner 9, Viking, Phobos and MGS orbiters have provided information upon the thermal profile, the chemical composition, the stratospheric winds, some isotopic ratios, and the properties of suspended dust. However, further remote sensing monitoring is still needed for a better understanding of the water cycle, a more accurate knowledge of the minor species and the aerosol composition, an improved measurement of the hydrogen and oxygen isotopic ratios, and for a full mapping of the middle altitude winds. Some of these information will be provided with the Mars Express mission.