Multispectral lidar to study the atmospheric aerosols chemical composition: measurements in Buenos Aires of ashes from volcano Calbuco eruption.

EZEQUIEL PAWELKO; JACOBO SALVADOR; JUAN PALLOTTA; EDUARDO QUEL

Kobe

Conferencia; The 13 th Atmospheric Sciences and Application to Air Quality (ASAAQ13); 2015

Meteorological Society of Japan, National Institute for Environmental Studies, and RIKEN Advanced Institute for Computational Science et al.,

The Lidar Division of CEILAP is developing a lidar (Light Detection and Ranging) to study the chemical composition of atmospheric aerosols in Argentinean Lidar Network. The instrument works with fluorescence, elastic and inelastic scattering in order to characterize the atmospheric particles in real time and with high spatial, temporal and spectral resolution. The transmission system isimplemented by a Nd:Yag laser which emits in its first three harmonics (1064, 532 and 355 nm) at 10Hz. Reception is performed with three Newtonian telescopes. The main telescope has 50 cm diameter area and it is used to collect the fluorescence and Raman backscatter in coaxial arrangement with the laser beam. Two other telescopes with 20 cm diameter are used in biaxial setup for recover532 nm orthogonal polarization backscatter and Mie, Raman and Rayleigh Backscatter (355, 532, 1064, 387, 408 and 607 nm), respectively. The Raman and fluorescence signals generated by laser interaction (532 or 355 nm) with the molecules composing atmospheric aerosols are processed with a multispectral acquisition system. The multispectral device consists of a Crossed Czerny-Turnerspectrometer, a 32 channels hybrid photomultiplier and a photocount detection system which works at 15 m spatial and 4.5 nm spectral resolutions. This method allows to recover Raman and fluorescence spectrum within the atmospheric boundary layer and the first kilometers of the free atmosphere. The instrumental setup and the measurements of ashes from volcano Calbuco eruption on April 2015 are presented and discussed.