HR: 1340h
AN: A43D-1570    [Abstracts]
TI: Aerosol Optical Properties Characterization By Means Of The CNR-IMAA Multi-Wavelength Raman Lidar
AU: * Mona, L
EM: mona@imaa.cnr.it
AF: Consiglio Nazionale delle Ricerche- Istituto di Metodologie per l'Analisi Ambientale CNR- IMAA, C.da S.Loja, Tito Scalo, Potenza, 85050, Italy
AU: Amodeo, A
EM: amodeo@imaa.cnr.it
AF: Consiglio Nazionale delle Ricerche- Istituto di Metodologie per l'Analisi Ambientale CNR- IMAA, C.da S.Loja, Tito Scalo, Potenza, 85050, Italy
AU: D'Amico, G
EM: damico@imaa.cnr.it
AF: Consiglio Nazionale delle Ricerche- Istituto di Metodologie per l'Analisi Ambientale CNR- IMAA, C.da S.Loja, Tito Scalo, Potenza, 85050, Italy
AU: Pappalardo, G
EM: pappalardo@imaa.cnr.it
AF: Consiglio Nazionale delle Ricerche- Istituto di Metodologie per l'Analisi Ambientale CNR- IMAA, C.da S.Loja, Tito Scalo, Potenza, 85050, Italy
AB: A Raman/elastic lidar for tropospheric aerosol study is operational at CNR-IMAA (40°36'N, 15°44'E, 760 m above sea level) since May 2000 in the framework of EARLINET. Since August 2005, this system provides aerosol backscatter coefficient profiles at 1064 nm, and independent measurements of aerosol extinction and backscatter coefficient profiles at 355 and 532 nm. In this way, lidar ratio (i.e. extinction to backscatter ratio) profiles at 355 and 532 nm are also obtained. In addition, depolarization ratio measurements at 532 nm are obtained by means of detection of components of backscattered light polarized perpendicular and parallel to the direction of the linearly polarized transmitted laser beam. Depolarization ratio measurements provide information about shape and orientation of aerosolic particles, while lidar ratio measurements and wavelength dependences of both backscatter and extinction are important for aerosol characterization in terms of aerosol type and size. In addition, high quality multi-wavelength measurements (3 backscatter + 2 extinction) can allow the determination of microphysical aerosol properties (refractive index, single-scattering albedo and effective particles radii).
Systematic measurements are performed three times per week according to the EARLINET schedule since May 2000, and further measurements are performed in order to investigate particular events, like dust intrusions, volcanic eruptions and forest fires. This extended dataset allows the optical characterization of aerosol located close to the surface, namely in the Planetary Boundary Layer, as well as in the free troposphere. In the free troposphere, an high occurrence of Saharan dust intrusions at CNR-IMAA (about 1 day of Saharan dust intrusion every 10 days) has been identified by means of back-trajectory analysis and in accordance with satellite images, because of the short distance from the Sahara region. In addition, CNR-IMAA is pretty close to Etna, the largest European volcano, providing the opportunity to characterize volcanic aerosol properties too. Moreover, forest fires contribution to the aerosol load is not negligible during summer, when large forest fires typically occur in Southern Europe. Therefore the CNR-IMAA multi-wavelength Raman lidar system allows the characterization of aerosol optical properties for a large variety of events and atmospheric situations and to study the aerosol properties modification processes occurred during their transportation over continental scale. ACKNOWLEDGMENTS
The financial support for EARLINET by the European Commission under grant RICA-025991 is gratefully acknowledged.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0360 Radiation: transmission and scattering
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting