Using wavelet technique for pattern recognition of Atmospheric Boundary Layer on lidar profiles during an intrusion of volcanic ashes from Chaitén on May 2008 in Buenos Aires

EZEQUIEL PAWELKO; C. D'ATTELLIS; R. O. SIME; PABLO ROBERTO RISTORI; LIDIA ANA OTERO; JUAN PALLOTTA; EDUARDO QUEL

Optica Pura y Aplicada

Sociedad Española de Óptica (S.E.D.O.)

Lugar: Madrid; Año: 2011

0030-3917

Lidar is the most powerful tool to study the temporary evolution of Atmospheric Boundary Layer. At the Lidar Division at CEILAP (CITEDEF-CONICET) a Multiwavelength Raman-Rayleigh Lidar optimized to study the Boundary Layer is operated. This instrument is used to monitor important aerosol intrusion events in Buenos Aires, like the arrival of volcanic ashes from the Chaitén volcano eruption on May 2008, which was the first monitoring of volcanic ash in Argentina with lidar. In this event several volcanic ash plumes with high aerosol optical thickness into the free atmosphere were detected, it affecting the visibility, surface radiation and ABL evolution. This work presents a study of this ABL evolution using algorithms based on Covariance Wavelet Transform. The wavelet technique was chosen for its potential to recognition patterns in lidar backscatter profiles. In addition, the Boundary Layer Top (BLT), Entrainment Zone Thickness (EZT) and the Entrainment Flux Ratio (EFR) of the event are presented.