Juan Vicente Pallotta

Towards an instrumental harmonization in the framework of LALINET: dataset of technical specifications

The Latin American Lidar Network (LALINET) is the aerosol lidar network operating over South America. LALINET is now an operative network performing a schedule of routine measurements and, currently, is composed by 9 stations distributed over South America. The main objective of LALINET is to generate a consistent and statistically relevant database to enhance the understanding of the particle distribution over the continent and its direct and indirect influence on climate. The creation of an un-biased spatiotemporal database requires a throughout review of the network on two pillars: instrumentation and data processing. Because most of the LALINET systems are not series-produced instruments and, therefore, present large differences in configuration and capabilities, attempts for network harmonization and, consequently, optimization are mandatory. In this study a review of the current instrumental status of all LALINET systems is done and analyzed in detail in order to assess the potential performance of the network and to detect networking weaknesses.

Monitoring volcanic ash in the atmosphere

Fil: Chouza, Fernando. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Cientificas y Tecnicas para la Defensa. Centro de Investigacion en Laseres y Aplicaciones; Argentina

Biomass burning aerosol detection over Buenos Aires City, August 2009

At the end of August 2009, a biomass burning aerosol intrusion event was detected at the Laser and Applications Research Center, CEILAP (CITEFA-CONICET) (34.5° S – 58.5° W) at Villa Martelli, in Buenos Aires, Argentina. This center has a sunphotometer from the AERONET-NASA global network, UV solar radiation sensors, a meteorological station and an aerosol lidar system. The aerosol origin was determined by means of back-trajectories and satellite images. This work studies the aerosol air mass optical characterization and their effect in UV solar radiation.

Method to Detect Molecular Ranges in Elastic Lidar Signal

espanolSe presenta un metodo para la deteccion de plumas de aerosoles o nubes en una senal lidar elastica, como tambien, la determinacion de la altura de capa limite atmosferica. El objetivo de este trabajo es discriminar plumas de aerosoles o nubes de rangos Rayleigh puros, como tambien, la determinacion de la altura de la capa limite atmosferica. Este metodo esta basado en el concepto denominado Rayleigh-fit, donde la senal elastica corregida en rango es ajustada con una senal lidar Rayleigh pura formada con datos de radiosondeo. Para ejecutar este algoritmo, solo es necesaria de promediacion temporal, y solo un parametro de entrada es necesario para la ejecucion del metodo. Se realiza un analisis del metodo con senales medidas de diferentes sistemas lidar y se muestran sus resultados y limitaciones. EnglishA method to detect aerosol plumes or clouds from an elastic lidar signal is presented, as well the determination of the atmospheric boundary layer height. It is based on the Rayleigh-fit concept, where the range-corrected elastic lidar signal is fitted with a pure-Rayleigh range-corrected lidar signal formed by radiosonde data. To run the algorithm, only temporal averaging has to be taken into account, and only one input parameter is needed. An analysis of the method is performed using real lidar data from different lidar system, showing the results and its limitations.

Multi-wavelength scanning Raman lidar simulations for the Cherenkov Telescope Array observatory

This paper discusses the multi-wavelength scanning Raman lidar being built at Lidar Division, CEILAP (CITEDEF-CONICET) in the frame of the Argentinean CTA (Cherenkov Telescope Array) collaboration. CTA is an initiative to build the next generation of ground-based instruments to collect very high energy gamma-ray radiation (greater than a few tens of GeV). The atmospheric conditions are of major interest to CTA, and lidars are requested to acquire atmospheric profiles fast, accurately and in the line of sight of the event. Due to the expected low aerosol optical depth of the future site, the short observation period as well as the extension of the observation, an enhanced collection area is required. Based on this constraints, and energy laser pulse, a backscatter lidar signal simulation was performed to estimate the main characteristics of the system. To derive these features, a SNR (signal-to-noise ratio) was also simulated to derive the total number of mirrors to achieve a good quality signal over the whole tropopause. Raman capabilities were added in the UV and VIS wavelengths to retrieve the spectral characteristics of the aerosol extinction and the water vapor profile. The results of the simulation, and the main characteristics derived are shown.

Monitoring Aerosol Optical Properties in the ABL, Using Lidar System and Sunphotometer in Buenos Aires, Argentina

At the Lasers and Applications Research Center (CEILAP, CITEFA‐CONICET, (34°33′ S, 58°30′ W), located in an industrial suburb of the metropolitan area (Villa Martelli, Buenos Aires, Argentina), operates a multiwavelength lidar, based on a Nd:Yag laser (Continuum Surelite III P‐IV). This system emits in 1064, 532 and 355 nm simultaneously (10 Hz, 600 mJ @ 1064 nm) and allows the monitoring of the optical aerosols properties in the atmospheric boundary layer (ABL). On the same experimental site, an AERONET sunphotometer provides the AOT value. An analysis of boundary layer behaviour in some relevant days of March, from the years 2004 to 2006 is presented. On the days analyzed, no aerosols events and clouds were registered over the ABL. Evolutions of some characteristics of the ABL are presented, such as the height of the boundary layer, height of entrainment zone (EZ) and the entrainment flux ratio.

Using Lidar to Measure the Ozone Layer

South American scientists are using lidar technology to measure stratospheric ozone, water vapor and aerosols in Argentine Patagonia. Their work is helping to monitor global climate change, and has led to the development of a method for alerting local populations to the presence of the ozone hole.