US EPA

3241503 

Journal Article 

Water vapour mixing ratio distribution in the area of Naples by Raman lidar measurements and a high resolution model - art. no. 67450X 

Frontoso, MG; Ferretti, R; Pisani, G; Wang, X; Spinelli, N 

2007 

Unk 

Proceedings of SPIE
ISSN: 0277-786X
EISSN: 1996-756X 

PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) 

6745 

X7450-X7450 

WOS:000253868600024 

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 profilin systems and its impact on 9 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/NCAR(1,2) for this study.
Water vapour mixing ratio observations have been detected in the Naples site (40 degrees 50'N,
14 degrees 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. 

water vapour; Raman lidar; hydrological model; Launch campaign