The atmospheric composition of Mars: ISM and ground-based observational data.

Monitoring the abundances of Martian minor constituents and searching for local variations can provide valuable information about the aeronomy of the Martian atmosphere. Recent results from the PHOBOS ISM experiment suggest possible local variations of the carbon monoxide (CO) abundance. Additional constraints have been given by ground-based observations of CO in the infrared (IR) and millimeter range, a search for minor species in the millimeter range, and the millimeter detection of deuterated water (HDO). From these data, information on the thermal profile and the vertical distribution low CO and H 2 O has been retrieved