FABIO JULIANO DA SILVA LOPES

FABIO JULIANO DA SILVA LOPES

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Lidar Processing Pipeline and Single Calculus Chain retrieval comparison
2024 - PALLOTTA, JUAN; LOPEZ, FABIO; MOREIRA, GREGORI; CACHEFFO, ALEXANDRE; BARBOSA, HENRIQUE
Lidar Processing Pipeline (LPP) is an ongoing open-source software project for retrieving elastic lidar signals. It is based on a fully configurable and automated algorithm capable of performing all the steps required for the analysis, from the correction of lidar signals to the retrieval of aerosol optical properties. The first results have been presented, using both synthetic and real lidar signals from different LALINET (Latin American Lidar Network) sites, which demonstrated promising results that are consistent with calibrated aerosol instrumentation. This work presents a comparison with Single Calculus Chain (SCC) using data from the São Paulo lidar station. The SCC is a well-established inversion chain from the European Aerosol Research Lidar Network (EARLINET), under the ACTRIS (Aerosol, Clouds and Trace gases Research InfraStructure Network) infrastructure. Since LPP and SCC are algorithms focused on heterogeneous lidar networks, a comparison of the usage, configuration, and automatization of both systems is provided. In addition, a retrieval comparison is conducted between the two algorithms, demonstrating good agreement between the two systems.
Validation of Aeolus L2B wind product at Porto Velho - Brazil
2024 - YOSHIDA, ALEXANDRE C.; LOPES, FABIO J.S.; VENTURINI, PATRICIA C.; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO
The Atmospheric Dynamics Mission ADM-Aeolus was successfully launched in August 2018 by the European Space Agency (ESA). The Aeolus mission carried a single instrument, the first-ever Doppler Wind Lidar (DWL) in space, called Atmospheric LAser Doppler INstrument (ALADIN). Circling the Earth in a polar sun-synchronous orbit at about 320 km altitude and a repeat cycle of 7 days, ALADIN operated at an ultraviolet (UV) wavelength of 355 nm, at a frequency of 50 Hz, providing vertical profiles of horizontal line-of-sight (HLOS) winds on a global scale. Aeolus's mission exceeded scientific expectations, initially designed for a 3-year lifetime, providing global coverage of wind profiles for almost five years. At the end of April 2023, the satellite initiated the assisted reentry process, and on July 28, 2023, it safely burned up upon reentering the Earth's atmosphere over Antarctica. In this study, we assessed the accuracy of the L2B wind products by collecting radiosonde data from the Porto Velho station in the North Region of Brazil (8.76 S, 63.91 W). The Aeolus satellite passed over the station twice weekly in two different orbits: the descending orbit at 10:04 UTC on Thursdays and the ascending orbit at 22:25 UTC on Saturdays. In this long-term validation, we focus on the descending orbit overpasses, comparing Aeolus L2B wind products and radiosondes launched daily at 12:00 UTC. Statistical validation was performed from October 2018 to March 2023, encompassing the entire period of the Aeolus mission.
Analyzing the influence of the planetary boundary layer height, ventilation coefficient, thermal inversions, and aerosol optical Depth on the concentration of PM2.5 in the city of São Paulo
2024 - MOREIRA, GREGORI de A.; MARQUES, MARCIA T.A.; LOPES, FABIO J. da S.; ANDRADE, MARIA de F.; LANDULFO, EDUARDO
Cases of intense air pollution have been a recurring problem in most of urban centers in different regions of the world. Although actions to mitigate pollutant emissions are fundamental, it is also necessary to understand which factors can favor their dispersion process. In this scenario, this paper presents, for the first time, a long-term analysis of the Planetary Boundary Layer Height (PBLH), estimated through lidar and radiosounding data, Ventilation Coefficient (VC), Thermal Inversions (TI), and Aerosol Optical Depth (AOD), for the city of São Paulo, demonstrating how these variables are related with PM2.5 concentration. The analyzes showed that PBLH and VC have a seasonal cycle, with higher values in summer and lower ones in winter. Furthermore, PBLH is affected by one local factor, the sea-breeze, which reduces the concentration of aerosols in the late afternoon, resulting in an underestimated PBLH obtained from lidar data. Furthermore, from AERONET data, a predominance of Black Carbon and small particles was observed in all seasons, which are associated with the feedback effect observed in winter. Such effect attenuates the increase of PBLH and VC in cases of high concentrations of PM2.5. Finally, it was presented a Generalized Linear Model, which combines VC, AOD and TI information as input and can estimate the PM2.5 concentration with a R2 = 0.93.
Impact of extreme wildfires from the Brazilian Forests and sugarcane burning on the air quality of the biggest megacity on South America
2023 - SOUTO-OLIVEIRA, CARLOS E.; MARQUES, MARCIA T.A.; NOGUEIRA, THIAGO; LOPES, FABIO J.S.; MEDEIROS, JOSE A.G.; MEDEIROS, ILCA M.M.A.; MOREIRA, GREGORI A.; DIAS, PEDRO L. da S.; LANDULFO, EDUARDO; ANDRADE, MARIA de F.
Recently, extreme wildfires have damaged important ecosystems worldwide and have affected urban areas miles away due to long-range transport of smoke plumes. We performed a comprehensive analysis to clarify how smoke plumes from Pantanal and Amazon forests wildfires and sugarcane harvest burning also from interior of the state of São Paulo (ISSP) were transported and injected into the atmosphere of the Metropolitan Area of São Paulo (MASP), where they worsened air quality and increased greenhouse gas (GHG) levels. To classify event days, multiple biomass burning fingerprints as carbon isotopes, Lidar ratio and specific compounds ratios were combined with back trajectories modeling. During smoke plume event days in the MASP fine particulate matter concentrations exceeded the WHO standard (>25 μg m−3 ), at 99 % of the air quality monitoring stations, and peak CO2 excess were 100 % to 1178 % higher than non-event days. We demonstrated how external pollution events such as wildfires pose an additional challenge for cities, regarding public health threats associated to air quality, and reinforces the importance of GHG monitoring networks to track local and remote GHG emissions and sources in urban areas.
Collaborative development of the Lidar Processing Pipeline (LPP) for retrievals of atmospheric aerosols and clouds
2023 - PALLOTTA, JUAN V.; CARVALHO, SILVANIA A. de; LOPES, FABIO J. da S.; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO; BARBOSA, HENRIQUE M.J.
Atmospheric lidars can simultaneously measure clouds and aerosols with high temporal and spatial resolution and hence help understand cloud–aerosol interactions, which are the source of major uncertainties in future climate projections. However, atmospheric lidars are typically custom-built, with significant differences between them. In this sense, lidar networks play a crucial role as they coordinate the efforts of different groups, provide guidelines for quality-assured routine measurements and opportunities for side-by-side instrument comparisons, and enforce algorithm validation, all aiming to homogenize the physical retrievals from heterogeneous instruments in a network. Here we provide a high-level overview of the Lidar Processing Pipeline (LPP), an ongoing, collaborative, and open-source coordinated effort in Latin America. The LPP is a collection of tools with the ultimate goal of handling all the steps of a typical analysis of lidar measurements. The modular and configurable framework is generic enough to be applicable to any lidar instrument. The first publicly released version of the LPP produces data files at levels 0 (raw and metadata), 1 (averaging and layer mask), and 2 (aerosol optical properties). We assess the performance of the LPP through quantitative and qualitative analyses of simulated and measured elastic lidar signals. For noiseless synthetic 532 nm elastic signals with a constant lidar ratio (LR), the root mean square error (RMSE) in aerosol extinction within the boundary layer is about 0.1 %. In contrast, retrievals of aerosol backscatter from noisy elastic signals with a variable LR have an RMSE of 11 %, mostly due to assuming a constant LR in the inversion. The application of the LPP for measurements in São Paulo, further constrained by co-located AERONET data, retrieved a lidar ratio of 69.9 ± 5.2 sr at 532 nm, in agreement with reported values for urban aerosols. Over the Amazon, analysis of a 6 km thick multi-layer cirrus found a cloud optical depth of about 0.46, also in agreement with previous studies. From this exercise, we identify the need for new features and discuss a roadmap to guide future development, accommodating the needs of our community.
Analyzing the influence of vehicular traffic on the concentration of pollutants in the city of São Paulo
2023 - MOREIRA, GREGORI de A.; CACHEFFO, ALEXANDRE; ANDRADE, IZABEL da S.; LOPES, FABIO JULIANO da S.; GOMES, ANTONIO A.; LANDULFO, EDUARDO
This study employs surface and remote sensing data jointly with deep learning techniques to examine the influence of vehicular traffic in the seasonal patterns of CO, NO2 , PM2.5, and PM10 concentrations in the São Paulo municipality, as the period of physical distancing (March 2020 to December 2021), due to SARS-CoV-2 pandemic and the resumption of activities, made it possible to observe significant variations in the flow of vehicles in the city of São Paulo. Firstly, an analysis of the planetary boundary layer height and ventilation coefficient was performed to identify the seasons’ patterns of pollution dispersion. Then, the variations (from 2018 to 2021) of the seasonal average values of air temperature, relative humidity, precipitation, and thermal inversion occurrence/position were compared to identify possible variations in the patterns of such variables that would justify (or deny) the occurrence of more favorable conditions for pollutants dispersion. However, no significant variations were found. Finally, the seasonal average concentrations of the previously mentioned pollutants were compared from 2018 to 2021, and the daily concentrations observed during the pandemic period were compared with a model based on an artificial neural network. Regarding the concentration of pollutants, the primarily sourced from vehicular traffic (CO and NO2 ) exhibited substantial variations, demonstrating an inverse relationship with the rate of social distancing. In addition, the measured concentrations deviated from the predictive model during periods of significant social isolation. Conversely, pollutants that were not primarily linked to vehicular sources (PM2.5 and PM10) exhibited minimal variation from 2018 to 2021; thus, their measured concentration remained consistent with the prediction model.
Collaborative development of a Lidar Processing Pipeline
2021 - PALLOTTA, JUAN; LOPES, FABIO; BARBOSA, HENRIQUE M.J.; CARVALHO, SILVANIA A.; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO
Aerosols, clouds and their interactions are the source of the largest uncertainties in current climate change estimates. More frequent and higher quality measurement of aerosol, clouds, and the physical processes governing their link with climate are needed to reduce these uncertainties, and lidars are a powerful instrument to accomplish this task. However, lidars are generally developed by individual groups for particular applications, and hence typically have very different characteristics. In this sense, lidar networks play a key role as they coordinate the efforts of different groups, providing the guidelines for quality-assured routine measurements on a regional scale. Moreover, a coordinated effort is of utmost importance to homogenize the physical retrievals from the highly non-uniform instruments in a network. This is only possible with the development of a unified processing pipeline that accounts for the hardware heterogeneity in the pool of instruments. Here, we describe an ongoing effort to collaboratively develop a Lidar Processing Pipeline. The LPP is a collection of tools developed in C++ and Python that are planned to handle all the steps of lidar analysis. A first tool converts the raw data files into a single NetCDF file, including detailed information about the instrument and acquisition setup (Level 0 dataset). . Then, this is processed by another tool which applies the necessary corrections and computes the cloud-mask (Level 1 dataset). The final step is the elastic and/or inelastic retrieval of aerosol properties (Level 2 dataset). The development of LPP has been based on the existing analysis routines developed by individual groups, and hence takes advantage of previous efforts for algorithm comparison in the scope of Lalinet Network. A general concept and first steps of the ongoing project are reported, as well as the next steps towards the release of the first operational version of the processing pipeline.
Study of optical properties and spatial distribution of cirrus clouds over São Paulo, Brazil, using CALIPSO level 2 data
2021 - SOUZA, GIOVANNI; LOPES, FABIO J.S.; LANDULFO, EDUARDO
Cirrus clouds have an important role in the earth’s radiation budget, they have a wide spatial extension and are the most present type of clouds in the atmosphere, especially in tropical regions (Sassen et al., 2018). Due their thickness, Cirrus clouds are almost transparent for the incoming shortwave solar radiation and opaque to the longwave emitted by the planet's surface. Despite the importance of Cirrus clouds in the earth’s climate, there is a lack of studies focused on this type of cloud in the southern hemisphere. Since 2006, the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), a joint mission between NASA and the French space agency, CNES, provides physical and optical information of clouds and aerosols to improve the understanding of their role in the climate, air quality and radiation budget in the Earth. The primary instrument of CALIPSO payload is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), which is a lidar system operating on 1064 nm and 532 nm (with parallel and perpendicular polarization) wavelengths. CALIOP provides as level 1 data, high-resolution vertical profiles of aerosols and clouds. In turn, the level 2 data provides processed products such as cloud-aersol discrimination, cloud base and top layer altitude, and cloud optical depth. The aim of this work is use the CALIOP global coverage to study the physical and optical properties of Cirrus clouds over the São Paulo State (roughly centered on 21.3°S, 50.3°W), in Brazil. We have employed a statistic analysis of 9 years (2007-2015) of data using the level 2 products to obtain spatial distribution and optical properties of cirrus clouds over São Paulo state, in order to understanding the long-term trend of Cirrus clouds coverage in the São Paulo state and later on Brazil.
LIDAR first campaign in the industrial sites of Volta Redonda-RJ and Lorena-SP, Brazil
2021 - CARVALHO, SILVANIA A.; LOPES, FABIO J.S.; SILVA, JONATAN J. da; MENEGATTI, CARLOS R.; CATALANI, FERNANDO; TODERO, CARLOS J.; RIBEIRO, FABIO de J.; ALMEIDA, ROGERIO M. de; LANDULFO, EDUARDO
Air pollution is recognized as a risk factor for health. The emission of toxic gases and particulates, specially with diameter size smaller than 10 μm, into the atmosphere by industries is correlated with increasing respiratory problems, mortality and cancer in some urban areas. Additionally the aerosol particles play an important role in the Earth’s radiation budget and the understanding of their properties is important to address their effects on the climate and weather conditions. In this study we will present some results of aerosol vertical distribution retrieved using a mobile lidar system and the lidar system on board of the CALIPSO satellite platform. The synergetic use of these platforms helped to understand the impact of the aerosol suspended in the atmosphere in terms of its optical properties in two different sites between two main metropolitan areas of Brazil, which are São Paulo and Rio de Janeiro. In order to obtain a statistical characterization of the aerosol optical properties, level 2-version 4 data from CALIPSO were employed to retrieve the AOD and Lidar ratio values at 532 nm for Volta Redonda and Lorena sites. Lorena campaign was performed during a very dry period in the 2014 Southern hemisphere winter, where it detected the vertical distribution profile with several layers detached from the aerosol boundary layer (ABL) on 26th of June 2014. Volta Redonda-RJ campaign performed from the beginning of November until mid of December of 2018 provided detection of aerosol layers detached from ABL on 4th of December of 2018. We will present a brief description of the experimental apparatus, the data taking, the methodology and the main results which open up the possibility to investigate emission of toxic gases and particulates at this region which has high contribution to local atmospheric pollution due to the Presidente Dutra highway (BR 116), the Companhia Siderúgica Nacional (CSN) and other metallurgical and cement factories.
Study of aerosol optical properties on South America using AERONET data analysis
2021 - JESUS, ESTER O. de; ROSARIO, NILTON M.E. do; YOSHIDA, ALEXANDRE C.; CACHEFFO, ALEXANDRE; GUERRERO-RASCADO, JUAN L.; LANDULFO, EDUARDO; LOPES, FABIO J.S.
In the last decade, a new generation of satellite missions have been developed using advanced lidar systems capable to retrieve several cloud and aerosol optical properties and distinguish different aerosol types by applying a polarization sensitive high spectral resolution lidar (HSRL) technique, as is the case of the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) mission, developed by the European Space Agency (ESA) together with the Japan Aerospace Exploration Agency (JAXA). The EarthCARE payload will be compound by four main instruments, a cloud profiling radar, with Doppler capability, the HSRL system, a multispectral imager and a broadband radiometer, enabling the retrieval of global profiles of clouds, aerosols, precipitation and radiation field properties. The Atmospheric Lidar system (ATLID) on board of EarthCARE will operate at 355 nm and will use the cross and co-polarized components of Mie and Rayleigh scattering to derive aerosol properties. An important task to be developed by ground-based research groups is the data validation process. In this context, the Latin American LIdar NETwork (LALINET) has been playing a key role in the cloud and aerosol studies by using lidar and/or the AERONET sunphotometers data. In order to prepare the most suitable strategy for calibration and validation (CAL/VAL) processes of the EarthCARE mission, we have employed an extensive study of aerosol optical properties derived from 21 AERONET sunphotometer stations all over South America, from a period of at least 20 year. The aim of this work is to present preliminary results of columnar aerosol optical properties, such as AOD, lidar ratio, scattering and absorption Angstrom Exponent, single-scaterring albedo and aerosol fine-mode fraction, in order to select cluster-zones by aerosol types to guide the validation methodology for ATLID system products, since the continent is dominated by high spatial and temporal variability of aerosol systems.