Cloud-top temporal variation of Saturn's 2011-2012 stratospheric vortex by means of Cassini/VIMS-V data analysis

In this work, selected regions of the giant vortex observed at Saturn since January 2011, have been investigated by analyzing the observations from the visual channel of the Visual and Infrared Mapping Spectrometer (VIMS-V) on board the Cassini spacecraft. Previously, a forward radiative transfer model has been developed, based on the LibRadtran code [13], adapted to the atmosphere of Saturn. Then an inverse code, based on the optimal estimation technique [14], has been implemented to retrieve the microphysical and geometrical properties of the clouds. Best fits of the radiance spectra relative to the vortex are produced and then the cloud top pressures are estimated. Data retrieved on a time lapse of months allow to investigate the temporal variation of the vortex's cloud properties.