The optical properties and the spatial distribution of the tropospheric aerosols over Naples under Saharan dust outbreaks
conditions have been studied by means of lidar measurements performed between May 2000 and August 2003 in the
frame of the EARLINET project. Climatological analysis of sand plume has been done by comparing normal and dust
affected conditions. Results in terms of backscattering and extinction coefficient as well as their integrated quantities
show that the aerosol load from the ground level up to 2 Km during Saharan dust transport events is almost the same of
normal conditions. This is probably due to the relevant widespread of local aerosol sources, such as vehicular traffic,
industrial activities, etc. Nevertheless, when sand outbreaks occur, the extinction to backscattering ratio, i.e. the lidar
ratio, clearly shows that the aerosol type in the lowest atmospheric layer changes. Moreover, Saharan dust transport
events strong increase both integrated backscatter and optical dept above 2 km.
The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite had been launched in April 2006. Its main goal is to probe the vertical structure and to measure the properties of thin clouds and aerosols plume of the Earth's atmosphere. In order to validate the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) products, correlative measurements between CALIPSO and EARLINET stations have been planned in the framework of the validation campaign. At Napoli EARLINET station correlative measurement have been performed starting from the beginning of June 2006. Results obtained both during daytime with elastic lidar and nighttime with Raman lidar operating at two wavelengths (355nm and 532nm) are shown. The results of the application of a new algorithm to retrieve aerosol basckscattering and extinction coefficient backscattering from space and ground based elastic lidar signals are presented. Case study of Saharan dust outbreaks and cirrus clouds captured during correlative measurement runs are discussed.
During August-October 2005, several lidar measurements have been performed at many Italian lidar stations during the
Launch (International Lindenberg campaign for Assessment of hUmidity aNd Cloud profiling systems and its impact on
High-resolution modelling) campaign according with the IOP (Intensive Operational Period) schedule.
IOP 4 episode (1-3 October 2005) has been selected and investigated with a special attention to the variability of water
vapour mixing ratio vertical distribution to better understand the associated circulation in the coastal waters of the Gulf
of Naples (Tyrrhenian Sea).
A simulation is performed using the mesoscale model MM5 (version 3) model from PSU/NCAR1,2 for this study. Water
vapour mixing ratio observations have been detected in the Naples site (40°50'N, 14°11'E, 118 m asl) by a water vapour
Raman lidar which is also able to measure the backscatter profile at 355 and 532 nm and the extinction profile at 355
nm.
Water vapour mixing ratio vertical profiles retrieved by lidar have been compared with the MM5 water vapour mixing
ratio vertical profiles. The agreement between the model and the lidar data is good; all the modelled and the lidar profiles
are able to capture the cold air intrusion, that is the sharp decrease of the water vapour mixing ratio at about 2000 m.
Also the water-layer between 3000 and 8000 m is well captured. Moreover, both the model and the observations are able
to capture the land/sea breeze phenomena.
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