Results from the Viking Orbiter Mars Atmospheric
Water Detectors (MAWD) have long been the definitive
data set for observations of the Martian water cycle
(Farmer et al., 1977). The ongoing Mars Global Surveyor
Thermal Emission Spectrometer (TES) observations
are providing new insights into the current water
cycle, with detailed longitude-latitude dependence of
water vapour (Figure 1) and water cloud (Figure 2) with
time, as well as information on vertical distribution of
water vapour and ice cloud (Smith, 2001). The described
results are derived from an ongoing project to model the
currentwater cycle using the Oxford version of the European
Mars General Circulation Model (MGCM) (Forget
et al., 1999), which was developed in colaboration with
LMD, Paris
