IROE-CNR, Firenze(Italy)

We present some preliminary results of MOANA (Measurements and modelling of Ozone and Aerosols in the Northern Atmosphere) multi-wavelength lidar system, which was operating at Sodankyla (SF) during SESAME. We observed various polar stratospheric cloud (PSC) episodes; in this work we report the measurements of January 12 (JI2) and January 19 (J19), 1995. The J12 PSC has a layered structure and two of the three particle layers show a depolarised backscattering signal. On the other hand the J19 PSC detected between 19 and 24km is likely composed of spherical (liquid) particles because no depolarization shows up. In the last case an analysis of the lidar backscattering at the different wavelengths allows to estimate the optical size distribution of the particles.