IZABEL DA SILVA ANDRADE
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Artigo IPEN-doc 30209 Comparison of PBL heights from ceilometer measurements and greenhouse gases concentrations in São Paulo2023 - SANTOS, AMANDA V. dos; ARAUJO, ELAINE C.; ANDRADE, IZABEL da S.; CORREA, THAIS; MARQUES, MARCIA T.A.; SOUTO-OLIVEIRA, CARLOS E.; LEONARDO, NOELE F.; MACEDO, FERNANDA de M.; SOUZA, GIOVANNI; LOPES, PEROLA P. de Q.; MOREIRA, GREGORI de A.; ANDRADE, MARIA de F.; LANDULFO, EDUARDOThis paper presents a study conducted in São Paulo, Brazil, where the planetary boundary layer height (PBLH) was determined using ceilometer data and the wavelet covariance transform method. The retrieved PBLH values were subsequently compared with the concentrations of CO2 and CH4 measured at three distinct experimental sites in the city. The period of study was July 2021. This study also included a comparison between ceilometer data and lidar data, which demonstrated the favorable applicability of the ceilometer data for PBLH estimation. An examination of the correlation between changes in average CO2 concentrations and PBLH values revealed stronger correlations for the IAG and UNICID stations, with correlation coefficients (ρ) of approximately −0.86 and −0.85, respectively, in contrast to the Pico do Jaraguá station, which exhibited a lower correlation coefficient of −0.42. When assessing changes in CH4 concentrations against variations in PBL height, the retrieved correlation coefficients were approximately −0.78 for IAG, −0.66 for UNICID, and −0.38 for Pico do Jaraguá. The results indicated that CO2/CH4 concentrations are negatively correlated with PBL heights, with CO2 concentrations showing more significant correlation than CH4 . Additionally, among the three measurement stations, IAG measurements displayed the most substantial correlation. The results from this study contribute to the understanding of the relationship between PBLH and greenhouse gas concentrations, emphasizing the potential of remote sensing systems like ceilometers in monitoring and studying atmospheric processes.Artigo IPEN-doc 28827 Photochemical sensitivity to emissions and local meteorology in Bogotá, Santiago, and São Paulo2022 - SEGUEL, RODRIGO J.; GALLARDO, LAURA; OSSES, MAURICIO; ROJAS, NESTOR Y.; NOGUEIRA, THIAGO; MENARES, CAMILO; ANDRADE, MARIA de F.; BELALCAZAR, LUIS C.; CARRASCO, PAULA; ESKES, HENK; FLEMING, ZOE L.; HUNEEUS, NICOLAS; IBARRA-ESPINOSA, SERGIO; LANDULFO, EDUARDO; LEIVA, MANUEL; MANGONES, SONIA C.; MORAIS, FERNANDO G.; MOREIRA, GREGORI A.; PANTOJA, NICOLAS; PARRAGUEZ, SANTIAGO; ROJAS, JHOJAN P.; RONDANELLI, ROBERTO; ANDRADE, IZABEL da S.; TORO, RICHARD; YOSHIDA, ALEXANDRE C.This study delves into the photochemical atmospheric changes reported globally during the pandemic by analyzing the change in emissions from mobile sources and the contribution of local meteorology to ozone (O3) and particle formation in Bogotá (Colombia), Santiago (Chile), and São Paulo (Brazil). The impact of mobility reductions (50%–80%) produced by the early coronavirus-imposed lockdown was assessed through high-resolution vehicular emission inventories, surface measurements, aerosol optical depth and size, and satellite observations of tropospheric nitrogen dioxide (NO2) columns. A generalized additive model (GAM) technique was also used to separate the local meteorology and urban patterns from other drivers relevant for O3 and NO2 formation. Volatile organic compounds, nitrogen oxides (NOx), and fine particulate matter (PM2.5) decreased significantly due to motorized trip reductions. In situ nitrogen oxide median surface mixing ratios declined by 70%, 67%, and 67% in Bogotá, Santiago, and São Paulo, respectively. NO2 column medians from satellite observations decreased by 40%, 35%, and 47%, respectively, which was consistent with the changes in mobility and surface mixing ratio reductions of 34%, 25%, and 34%. However, the ambient NO2 to NOx ratio increased, denoting a shift of the O3 formation regime that led to a 51%, 36%, and 30% increase in the median O3 surface mixing ratios in the 3 respective cities. O3 showed high sensitivity to slight temperature changes during the pandemic lockdown period analyzed. However, the GAM results indicate that O3 increases were mainly caused by emission changes. The lockdown led to an increase in the median of the maximum daily 8-h average O3 of between 56% and 90% in these cities.Artigo IPEN-doc 26790 Correlation between two different real time data acquisition systems2019 - MACEDO, FERNANDA M.; CORREA, THAIS; ARAUJO, ELAINE; ANDRADE, IZABEL; ARLEQUES, ANTONIO G.; MIRANDA, JULIANA T. de M.; SILVA, JONATAN da; GUARDANI, ROBERTO; VESELOVSKII, IGOR; LANDULFO, EDUARDOFugitive emissions, defined as unintended or irregular leaks of gases and vapors, these are an important source of pollutants to the atmosphere, which is difficult to monitor and control. These sources are present in different sites, including megacities like São Paulo that are growing in size and economic activity. At the same time, there is a remarkable growth in concerns about the environmental issues associated with these activities. In a constantly changing world, with increasing concentrations of greenhouse gases (GHGs), among them methane (CH4) and volatile organic compounds (VOC), mitigation of atmospheric emission of these gases to contain global warming, make field campaigns in the metropolitan region of São Paulo very relevant. Optical remote sensing techniques as lidar can attend the need for real time and trustable information on fugitive emissions. The Cavity Ringdown Laser Spectroscopy (CRDS) technique was adopted because it is widely used in the detection of gas samples that absorb light at specific wavelengths and also for their ability to detect mole fractions up to the parts per trillion level. The Raman lidar system used includes a commercial laser pulsed Nd:YAG Quantel S.A., model CFR 200, with wavelengths of 355 nm, 353 nm and 396 nm, 120 mJ pulse power, with laser repetition rate of 20 Hz and pulse width of 20 s, with a spatial resolution of 7,5 m. The system includes an ethernet interface, used together with LabView software to control the measurement and readout of the acquired data. The mixing ratio of CH4 can be observed within the planetary boundary layer. The measured methane profiles correlate with the acquisitions made with the CRDS, however, an additional contribution of control data in which the Raman lines detect with high sensitivity.