ALEXANDRE CACHEFFO

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  • Capítulo IPEN-doc 28535
    Lidar observations in South America
    2021 - LANDULFO, EDUARDO; CACHEFFO, ALEXANDRE; YOSHIDA, ALEXANDRE C.; GOMES, ANTONIO A.; LOPES, FABIO J. da S.; MOREIRA, GREGORI de A.; SILVA, JONATAN J. da; ANDRIOLI, VANIA; PIMENTA, ALEXANDRE; WANG, CHI; XU, JIYAO; MARTINS, MARIA P.P.; BATISTA, PAULO; BARBOSA, HENRIQUE de M.J.; GOUVEIA, DIEGO A.; GONZALEZ, BORIS B.; ZAMORANO, FELIX; QUEL, EDUARDO; PEREIRA, CLODOMYRA; WOLFRAM, ELIAN; CASASOLA, FACUNDO I.; ORTE, FACUNDO; SALVADOR, JACOBO O.; PALLOTTA, JUAN V.; OTERO, LIDIA A.; PRIETO, MARIA; RISTORI, PABLO R.; BRUSCA, SILVINA; ESTUPINAN, JOHN H.R.; BARRERA, ESTIVEN S.; ANTUNA-MARRERO, JUAN C.; FORNO, RICARDO; ANDRADE, MARCOS; HOELZEMANN, JUDITH J.; GUEDES, ANDERSON G.; SOUSA, CRISTINA T.; OLIVEIRA, DANIEL C.F. dos S.; DUARTE, EDICLE de S.F.; SILVA, MARCOS P.A. da; SANTOS, RENATA S. da S.
    In Part II of this chapter, we intend to show the significant advances and results concerning aerosols’ tropospheric monitoring in South America. The tropospheric lidar monitoring is also supported by the Latin American Lidar Network (LALINET). It is concerned about aerosols originating from urban pollution, biomass burning, desert dust, sea spray, and other primary sources. Cloud studies and their impact on radiative transfer using tropospheric lidar measurements are also presented.
  • Capítulo IPEN-doc 28534
    Lidar observations in South America
    2021 - LANDULFO, EDUARDO; CACHEFFO, ALEXANDRE; YOSHIDA, ALEXANDRE C.; GOMES, ANTONIO A.; LOPES, FABIO J. da S.; MOREIRA, GREGORI de A.; SILVA, JONATAN J. da; ANDRIOLI, VANIA; PIMENTA, ALEXANDRE; WANG, CHI; XU, JIYAO; MARTINS, MARIA P.P.; BATISTA, PAULO; BARBOSA, HENRIQUE de M.J.; GOUVEIA, DIEGO A.; GONZALEZ, BORIS B.; ZAMORANO, FELIX; QUEL, EDUARDO; PEREIRA, CLODOMYRA; WOLFRAM, ELIAN; CASASOLA, FACUNDO I.; ORTE, FACUNDO; SALVADOR, JACOBO O.; PALLOTTA, JUAN V.; OTERO, LIDIA A.; PRIETO, MARIA; RISTORI, PABLO R.; BRUSCA, SILVINA; ESTUPINAN, JOHN H.R.; BARRERA, ESTIVEN S.; ANTUNA-MARRERO, JUAN C.; FORNO, RICARDO; ANDRADE, MARCOS; HOELZEMANN, JUDITH J.; GUEDES, ANDERSON G.; SOUSA, CRISTINA T.; OLIVEIRA, DANIEL C.F. dos S.; DUARTE, EDICLE de S.F.; SILVA, MARCOS P.A. da; SANTOS, RENATA S. da S.
    South America covers a large area of the globe and plays a fundamental function in its climate change, geographical features, and natural resources. However, it still is a developing area, and natural resource management and energy production are far from a sustainable framework, impacting the air quality of the area and needs much improvement in monitoring. There are significant activities regarding laser remote sensing of the atmosphere at different levels for different purposes. Among these activities, we can mention the mesospheric probing of sodium measurements and stratospheric monitoring of ozone, and the study of wind and gravity waves. Some of these activities are long-lasting and count on the support from the Latin American Lidar Network (LALINET). We intend to pinpoint the most significant scientific achievements and show the potential of carrying out remote sensing activities in the continent and show its correlations with other earth science connections and synergies. In Part I of this chapter, we will present an overview and significant results of lidar observations in the mesosphere and stratosphere. Part II will be dedicated to tropospheric observations.
  • Resumo IPEN-doc 27965
    Validation of AEOLUS L2A products using a multiwavelength lidar system at SPU Lidar Station - Brazil
    2020 - LOPES, FABIO; YOSHIDA, ALEXANDRE; CACHEFFO, ALEXANDRE; SILVA, JONATAN; MOREIRA, GREGORI; LANDULFO, EDUARDO
  • Artigo IPEN-doc 27830
    COVID-19 outbreak and air quality
    2021 - MOREIRA, GREGORI de A.; ANDRADE, IZABEL da S.; CACHEFFO, ALEXANDRE; YOSHIDA, ALEXANDRE C.; GOMES, ANTONIO A.; SILVA, JONATAN J. da; LOPES, FABIO J. da S.; LANDULFO, EDUARDO
    This work compares variations in the concentrations and air quality indexes of the pollutants PM10, PM2.5, CO, and NO2, during the COVID-19 outbreak in São Paulo Municipality. Such comparisons considered the period of physical distancing (autumn) and the three first months of economic activities’ resumption (winter). The concentrations and indexes observed in 2020 were compared with their correspondent values measured in the three preceding years. Also, from a supervised machine learning algorithm, the correspondent 2020 expected values were predicted and used in these comparisons. In order to analyze the influence of meteorological conditions, the seasons studied were characterized using remote sensing and surface data. The pollutants predominantly emitted by the vehicle fleet (CO and NO2) had reductions in their concentrations, with values always below the predictions and good air quality indexes. However, the pollutants whose concentration is less dependent on automotive emissions (PM10 and PM2.5) had high proximity to the predictions during the autumn and lower values during some periods in winter. This reduction was not enough to avoid days with a moderate air quality index. The approximation of the average concentrations of PM10, PM2.5, and CO to the prediction, from the second-half August 2020, indicates the influence of activities’ resumption in air quality.
  • Artigo IPEN-doc 27755
    Influence of a biomass-burning event in PM2.5 concentration and air quality
    2021 - MOREIRA, GREGORI de A.; ANDRADE, IZABEL da S.; CACHEFFO, ALEXANDRE; LOPES, FABIO J. da S.; YOSHIDA, ALEXANDRE C.; GOMES, ANTONIO A.; SILVA, JONATAN J. da; LANDULFO, EDUARDO
    Severe biomass burning (BB) events have become increasingly common in South America in the last few years, mainly due to the high number of wildfires observed recently. Such incidents can negatively influence the air quality index associated with PM2.5 (particulate matter, which is harmful to human health). A study performed in the Metropolitan Area of São Paulo (MASP) took place on selected days of July 2019, evaluated the influence of a BB event on air quality. Use of combined remote sensing, a surface monitoring system and data modeling and enabled detection of the BB plume arrival (light detection and ranging (lidar) ratio of (50 ± 34) sr at 532 nm, and (72 ± 45) sr at 355 nm) and how it affected the Ångström exponent (>1.3), atmospheric optical depth (>0.7), PM2.5 concentrations (>25 µg.m−3), and air quality classification. The utilization of high-order statistical moments, obtained from elastic lidar, provided a new way to observe the entrainment process, allowing understanding of how a decoupled aerosol layer influences the local urban area. This new novel approach enables a lidar system to obtain the same results as a more complex set of instruments and verify how BB events contribute from air masses aloft towards near ground ones.