  One of the striking features about Venus atmosphere is its temporal
variability and dynamics, with a chaotic polar vortex, large-scale atmospheric
waves, sheared features, and variable winds that depend on local time and
possibly orographic features. The aim of this research is to combine data
accumulated over several years and obtain a global mean state of the atmosphere
focusing in the global structure of the clouds using the cloud opacity and
upper cloud temperatures. We have first produced global maps using the
integrated radiance through the infrared atmospheric windows centred around
1.74{\mu}m and 2.25{\mu}m, that show the spatial variations of the cloud
opacity in the lower clouds around 44-48 km altitude and also provide an
indirect estimation of the possible particle size. We have also produced
similar global maps using the brightness temperatures seen in the thermal
region at 3.8{\mu}m and 5.0{\mu}m, which provide direct indication of the
temperatures at the top of the clouds around 60-70 km altitude. These maps have
been generated using the complete dataset of the Visible and InfraRed Thermal
Imaging Spectrometer mapping channel (VIRTIS-M) on board Venus Express, with a
wide spatial and long temporal coverage in the period from May 2006 until
October 2008. Our results provide a global view of the cloud opacity, particle
size and upper cloud temperatures at both hemispheres, showing the main
different dynamical regions of the planet. The profiles obtained also provide
the detailed dependencies with latitude, local time and longitude, diagnostic
of the global circulation flow and dynamics at various altitude layers, from
about 44 up to 70 km over the surface.
