DEVELOPMENT OF A NOVEL SUNPHOTOMETER FOR AEROSOL AND DUST CHARACTERIZATION IN THE ATMOSPHERE

The term aerosol refers to a suspension of solid particles or liquid droplets in a gaseous medium. During the last decades, aerosols and the need to measure them have become increasingly important. Aerosols can affect human health, because large loads of aerosols degrade air quality. Aerosols generated by volcanic eruptions can be a danger to aviation and impose diversion of air routes, resulting in economic damage. Finally, aerosols are the most uncertain cause of global climate change because their properties vary greatly in time and space. In this work we propose a novel ground-based sunphotometer to measure aerosols. It’s name is ARBOL (ARray of BOLometers). ARBOL is more flexible than common sunphotometers. The mechanical structure, the electronic layout and the acquisition software allow a better temporal resolution. In addition, six different wavelengths are measured simultaneously in the visible and near-infrared ranges. The thesis describes in detail the design, structure and implementation of each ARBOL component. Furthermore, instrumental characterizations and calibration are discussed. Finally, a first ARBOL has been installed at the Agency for the Protection of the Environment (ARPA, 583 a.s.l.) of Valle d’Aosta, while a second at the astronomical observatory of Saint Barthelemy (OAVdA) (1700 a.s.l.). The two measurement sites are located a few km apart from each other, but at different altitudes. Comparison of simultaneous measurements from the two sites allows information to be retrieved on the lowest atmospheric layer and its aerosol content. Consequently, the results of a test campaign are also discussed in this work.