Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Automatic light detection and ranging (532+1064 nm) for continuous PBL aerosol monitoring

Light detection and ranging (LIDAR) is a well known instrument for atmospheric science, but it is seldom used as a monitoring instrument. The developed system is automatic, performing a two wavelength monitoring of the PBL aerosols from 25 m above ground to 1500 m. Data are automatically collected every 5 minutes, and processed (in one hour one month of data is processed) as colour time-height plots of backscattering and backscattering-Angstrom coefficient. These plots permit a first, rough estimation of aerosol size. Number concentration can be retrieved for accumulation-mode aerosols. LIDAR data are automatically stored together with ground-based pollution data (14 stations) and meteo data (2 stations) with the same time resolution allowing a direct cross-analysis of LIDAR and ground data. The LIDAR system is useless in the absence of meteo and pollution data, and in this sense a link was implemented between the ground data (having no height resolution) and LIDAR data (giving not quantitative pollution data). The two types of data are automatically plotted together, permitting a first, quick, look at the daily situation and is available for the local authorities, pollution managers and modellers.At the IROE institute, optical models have been run using real aerosol models. The results allow determination of the approximate size of the aerosols in the accumulation mode starting from the two wavelength LIDAR data under special conditions, often verified in our urban PBL in Florence. These results allow estimation of the aerosol number concentration, or at least its magnitude (useful for PM2.5 policies) in most cases. The system is rather small, and can be moved by a van. A few hours are required to install and run it.

Reported by

IROE CNR
Via Panciatichi 64
50127 Florence
Italy
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