Eduardo Landulfo¹, Gerhard Held², Anderson Zanardis de Freitas¹, Alexandros Papayannis³, Renata Fernandes de Souza¹

¹Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN/CLA - São Paulo, Brazil
²Instituto de Pesquisas Meteorolégicas, Universidade Estadual Paulista, Bauru, São Paulo, Brazil
³National Technical University of Athens, Physics Department, Laser Remote Sensing Laboratory, Athens, Greece

The TroCCiBras (Tropical Convection and Cirrus experiment Brasil) campaign was conducted jointly with the European HIBISCUS and TROCCINOX projects from 21 January to 11 March 2004. The general objective of TroCCiBras, coordinated by IPMet/UNESP, was to obtain a set of special measurements throughout the troposphere and the lower stratosphere, to meet specific research needs of Brazilian research institutions, through the realization of the EU projects. Besides IPMet, six other Brazilian research institutions, as well as the German Max Planck Institute for Chemistry and the Lightning Research Group of Osaka University, Japan, participated actively in the field campaign. One of those invited Brazilian research groups was from the Instituto de Pesquisas Energéticas e Nucleares, which made its aerosol Lidar available in Bauru, in the central State of São Paulo, for the duration of the campaign. A unique data base has been established during the TroCCiBras Campaign, which had not been available before in the State of São Paulo, comprising simultaneous radar, lightning and lidar observations, as well as occasional pollutant and trace gas measurements from aircraft up to the mid-troposhere and from stratospheric balloons.The IPEN Lidar System was installed in the refurbished and specially adapted radar trailer of IPMet and based on the Campus of UNESP next to IPMet. It comprises a Nd:YAG laser in the 532 nm wavelength, with a repetition rate of 20 Hz and energy pulse as high 120 mJ. The backscattering signal was captured by a Newtonian telescope with 1,3 m of focal length. Attached to the telescope was a photomultiplier optimized for the visible spectrum with a 1 nm FWHM interference filter. In the beginning of the campaign, the data was digitized with a digital oscilloscope with 1 GHz bandwidth and 11-bit resolution; on 22 January 2004, this device was replaced with a transient recorder with the capability of simultaneous analog and photon counting measurements with a better resolution (12 bit). During the entire campaign, the system could be operated on 31 different days, during periods of about 4 hours in the morning, 4 in the afternoon and 6-8 hours during the night, which varied depending of the cloud/precipitation occurrences. Measurements were carried out during 6 days in January, 21 days in February and 4 days in March. The daytime measurements had a 15-30 m spatial resolution and maximum altitude of 10 km, while the night measurements had a 30-60 m resolution, reaching up to 30-35 km maximum altitude. The data to be presented will summarize these measurements with special emphasis of the planetary boundary layer altitude and its time evolution, cloud base height and some instances of calculated aerosol backscattering coefficient in the 532 nm. The analysis will be based on the availability of 105 radio-soundings, with up to 6 per day, made from the same site, as well as continuous radar observations from IPMet’s S-band Doppler radar in Bauru. The preliminary results certainly highlight the need for and benefits of operating an aerosol Lidar in the central State of São Paulo.