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Measurements and modelling of ozone and aerosols in the northern atmosphere

A better understanding of the processes linked to the ozone destruction in the Arctic is of primary importance. A study was made of the chemical and physical processes involved in the mechanism of ozone depletion of the Arctic region. The frequency of polar stratospheric cloud (PSC) episodes during the winter is linked to the decrease of ozone during the Arctic spring. During the study the stratospheric aerosols and PSC particles were characterized by means of their size distribution and refractive index. This research is of primary importance, since the phenomena of ozone destruction, due to the heterogeneous reactions which take place on the PSC particles, are strictly linked to the size and chemical composition of the aerosol present in the stratosphere. A new concept, multi-wavelength lidar system was realized for performing simultaneously the measurements of the backscattered light at: 355 nm, 532 nm, 750 nm and 1064 nm respectively, which allowed the characterization of PSC particles and ozone measurements. Two different laser sources were employed: a neodymium yttrium aluminium garnet (Nd-Yag) laser of Quanta Sytem for the radiation at 1064 nm, 532 nm, and 355 n, and a Ti-Sapphire laser of Elight Laser System for the 750 nm wavelength. Starting from the emission at 355 nm, the optical system was realized to acquire also the signal at 387 nm for the measurement of Raman signal of nitrogen. A special system for the acquisition and syncronization of the signal was built for acquiring simultaneously four wavelengths coming from two different sources. In particular a novel set-up was realized for the detection of the infrared (IR) backscattered radiation at 1064 nm.

Contact

Leopoldo STEFANUTTI, (Director)
Tel.: +39-055-4361691
Fax: +39-055-4249154
E-mail
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