Telma Castro - Academia.edu (original) (raw)

Papers by Telma Castro

The photolytic rate constant of nitrogen dioxide is a key parameter in air quality models. We pre... more The photolytic rate constant of nitrogen dioxide is a key parameter in air quality models. We present the first actual measurements of this rate constant in Mexico City. These were obtained with the use of an actinometer and the reactor, where a known concentration of NO, was photolysed for different experimental exposure times. Under the given experimental conditions, photolysis constants for NO? were determined during the day. This experiment is the first of its kind in Mexico.

Urban Climate, 2021

Abstract Black carbon (BC), carbon monoxide (CO), and carbon dioxide (CO2) were measured in Mexic... more Abstract Black carbon (BC), carbon monoxide (CO), and carbon dioxide (CO2) were measured in Mexico City (UNAM observatory) with a Photoacoustic Extinctiometer-PAX (BC) and a Cavity Ring-Down Spectroscopy analyzer-CRDS (CO and CO2), from November 2014 to July 2016. The objective of this study was to determine temporal variations of BC, CO, and CO2, their mutual correlations, and evaluation of the Mexico City emission inventory. The highest concentrations of pollutants were detected in cold dry season. The average concentrations of BC, CO, and CO2, for the entire period, were 2.95 μg m−3, 0.64 ppm, and 421.81 ppm, respectively. We calculated ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2 using three methods to obtain a confidence interval for the emission ratios. BC, CO, CO2 concentrations, and the ΔBC/ΔCO ratio were maximum in the early morning, while the ΔBC/ΔCO2 and ΔCO/ΔCO2 peak was maximum in the afternoon. BC and CO have a weekday/weekend difference. The estimated slopes (ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2) were compared with the emission ratios (BC/CO, BC/CO2, and CO/CO2) derived of the 2016 Mexico City emissions inventory. For mobile sources, the emission ratios of BC/CO and BC/CO2 were within the measurement range of ΔBC/ΔCO and ΔBC/ΔCO2, while CO/CO2 was underestimated in the emission inventory.

Atmospheric Pollution Research, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Me... more We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Mexico City. To estimate the spectral irradiance needed in the calculations, the equation of transfer is solved by the delta-Eddington method. An atmosphere of air, nitrogen dioxide, ozone and dry aerosol is modeled. INTRODUCTION A state-of-the art photochemical kinetics model requires the specification of time-dependant rates for the two most important photolytic reactions: NO + hy > NO + 0 (1) 0 + hv > 0 + 0(*D) (2) Transactions on Ecology and the Environment vol 1, © 1993 WIT Press, www.witpress.com, ISSN 1743-3541 324 Air Pollution These reactions take place in different portions of the solar spectrum from 280 nm to 410 nm. Indeed, reaction (2) take place below 340 nm whereas nitrogen dioxide is photolyzed mostly above 340 nm. Photolysis of nitrogen dioxide is the key reaction in photochemical smog. It plays a fundamental role as the sole immediate precursor for tropospheric ozon...

We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Me... more We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Mexico City. To estimate the spectral irradiance needed in the calculations, the equation of transfer is solved by the delta-Eddington method. An atmosphere of air, nitrogen dioxide, ozone and dry aerosol is modeled. INTRODUCTION A state-of-the art photochemical kinetics model requires the specification of time-dependant rates for the two most important photolytic reactions: NO + hy > NO + 0 (1) 0 + hv > 0 + 0(*D) (2) Transactions on Ecology and the Environment vol 1, © 1993 WIT Press, www.witpress.com, ISSN 1743-3541 324 Air Pollution These reactions take place in different portions of the solar spectrum from 280 nm to 410 nm. Indeed, reaction (2) take place below 340 nm whereas nitrogen dioxide is photolyzed mostly above 340 nm. Photolysis of nitrogen dioxide is the key reaction in photochemical smog. It plays a fundamental role as the sole immediate precursor for tropospheric ozon...

EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS ... more EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS NUEVAS ESTACIONES EN SITIOS M S ADECUADOS, AFIRMO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. CALIFICO DE ARBITRARIA LA LOCALIZACION DE LA RED ACTUAL. ALGUNAS ESTACIONES CERCA UNA DE LA OTRA, Y EN DELEGACIONES COMO XOCHIMILCO, MILPA ALTA Y CUAJIMALPA NO SE CUENTA CON MONITOREOS APROPIADOS, POR LO CUAL LA LOCALIZACION DE LAS NUEVAS INSTALACIONES DE LA RED DEBE HACERSE CON BASE EN UN ESTUDIO. RECONOCIO EL ESFUERZO DEL GOBIERNO DE LA CIUDAD PARA AMPLIAR LA RED DE MEDICIONES Y COMPLEMENTAR LAS QUE ACTUALMENTE EXISTEN CON M S SENSORES DE EVALUACION DE DIFERENTES CONTAMINANTES; EN LA ACTUALIDAD, HAY UN GRAN INTENTO POR MEDIR PARTICULAS DE 2.5 MICRAS, ANADIO. LA ESPECIALISTA INDICO QUE LAS PRINCIPALES EMISIONES CONTAMINANTES PROVIENEN DE LOS TUBOS DE ESCAPE DE LOS AUTOMOTORES, CUYA SOLUCION NO SOLO DEPENDE DE UNA DECISION POLITICA, SINO TAMBIEN CORRESPONDE A LOS CIUDADANOS FOMENTAR LA...

EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS ... more EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS NUEVAS ESTACIONES EN SITIOS M S ADECUADOS, AFIRMO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. CALIFICO DE ARBITRARIA LA LOCALIZACION DE LA RED ACTUAL. ALGUNAS ESTACIONES CERCA UNA DE LA OTRA, Y EN DELEGACIONES COMO XOCHIMILCO, MILPA ALTA Y CUAJIMALPA NO SE CUENTA CON MONITOREOS APROPIADOS, POR LO CUAL LA LOCALIZACION DE LAS NUEVAS INSTALACIONES DE LA RED DEBE HACERSE CON BASE EN UN ESTUDIO. RECONOCIO EL ESFUERZO DEL GOBIERNO DE LA CIUDAD PARA AMPLIAR LA RED DE MEDICIONES Y COMPLEMENTAR LAS QUE ACTUALMENTE EXISTEN CON M S SENSORES DE EVALUACION DE DIFERENTES CONTAMINANTES; EN LA ACTUALIDAD, HAY UN GRAN INTENTO POR MEDIR PARTICULAS DE 2.5 MICRAS, ANADIO. LA ESPECIALISTA INDICO QUE LAS PRINCIPALES EMISIONES CONTAMINANTES PROVIENEN DE LOS TUBOS DE ESCAPE DE LOS AUTOMOTORES, CUYA SOLUCION NO SOLO DEPENDE DE UNA DECISION POLITICA, SINO TAMBIEN CORRESPONDE A LOS CIUDADANOS FOMENTAR LA...

Atmospheric Environment, 2016

PM 2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijua... more PM 2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijuana during the Cal-Mex campaign from May 24 to June 5, 2010. Concentration of trace elements (Mg,

Atmospheric Environment, 2018

The role of the Tenango del Aire mountain pass, located southeast of the Mexico City Metropolitan... more The role of the Tenango del Aire mountain pass, located southeast of the Mexico City Metropolitan Area (MCMA), in venting the city's air pollution has already been studied from a meteorological standpoint. To better understand the transport of gaseous air pollutants through the Tenango del Aire Pass (TAP), and its influence on the air quality of the MCMA, three mobile air quality monitoring units were deployed during a 31-day field campaign between February and March of 2011. Surface O 3 , NO x , and meteorological variables were continuously measured at the three sites. Vertical profiles of O 3 and meteorological variables were also obtained at one of the sites using a tethered balloon. Days were classified as being under low pressure synoptic systems (LPS, 13 days), high pressure synoptic systems (HPS, 13 days), or as transition days (TR). The Mexican ozone standards at the Pass were not exceeded during LPS days, but were exceeded on almost all HPS days. A detailed analysis was performed using data from two typical days, one representative of LPS and the other of HPS. In both cases, morning vertical profiles of O 3 showed a strong thermal inversion layer and near-surface O 3 titration due to fresh NO x. In the LPS early morning, a single O 3 layer of close to 45 ppb

Atmosphere, 2022

Black carbon (BC), a component of carbonaceous material, has an important role in the environment... more Black carbon (BC), a component of carbonaceous material, has an important role in the environment, and it is considered a short-lived climate forcer that plays a vital role in the global climate system. BC concentrations were analyzed during 2017 in two sites in Mexico, Juriquilla and Altzomoni, which have different emission sources and atmospheric dynamics. The annual average BC concentrations in 2017 were 0.84 ± 0.70 and 0.58 ± 0.37 µg m−3 for Juriquilla and Altzomoni, respectively. The principal contributors for the highest BC concentration in Juriquilla were anthropogenic sources, while pollutants transport from nearby cities was more important for Altzomoni. Comparison between this analysis and previous reports from 2015 for both sampling sites demonstrated an increase in BC concentration. Results of this study could contribute to a better understanding of BC effects under different emission conditions and provide a scientific reference for developing BC reduction strategies ov...

TELMA GLORIA CASTRO ROMERO FUE DESIGNADA DIRECTORA DEL CENTRO DE CIENCIAS DE LA ATMOSFERA (CCA) D... more TELMA GLORIA CASTRO ROMERO FUE DESIGNADA DIRECTORA DEL CENTRO DE CIENCIAS DE LA ATMOSFERA (CCA) DE ESTA CASA DE ESTUDIOS, POR LOS PROXIMOS CUATRO ANOS (2013-2017).

EL AIRE ES UNO DE LOS ELEMENTOS B SICOS PARA LA SOBREVIVENCIA DE LOS SERES VIVOS, POR ELLO ES FUN... more EL AIRE ES UNO DE LOS ELEMENTOS B SICOS PARA LA SOBREVIVENCIA DE LOS SERES VIVOS, POR ELLO ES FUNDAMENTAL ESTUDIAR LOS PROBLEMAS RELACIONADOS CON SU DIN MICA EN LA ATMOSFERA, EN PARTICULAR SU CONTAMINACION Y COMPUESTOS QUE DETERMINAN LA CALIDAD DEL AIRE, ASEGURO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. AL PRESENTAR LA CONFERENCIA ATMOSFERA SIN FRONTERAS, COMO PARTE DEL PROGRAMA EDUCATIVO DEL PROYECTO MILAGRO (MEGACITY INITIATIVE: LOCAL AND GLOBAL RESEARCH OBSERVATIONS), SENALO QUE DESDE TIEMPOS REMOTOS EL HOMBRE ES CONSCIENTE DEL PELIGRO QUE REPRESENTA UNA ATMOSFERA CONTAMINADA, YA SEA POR UN FENOMENO NATURAL COMO UNA ERUPCION VOLC NICA O LA QUE OCASIONA EL HOMBRE MISMO POR SUS ACTIVIDADES. RECORDO QUE LA ATMOSFERA ES UNA CAPA GASEOSA DE APROXIMADAMENTE 10 MIL KILOMETROS DE ESPESOR QUE RODEA LA LITOSFERA E HIDROSFERA. EST COMPUESTA DE GASES Y PARTICULAS SOLIDAS Y LIQUIDAS EN SUSPENSION. EN ELLA SE PRODUCEN TODOS LOS FENOMENOS CLIM TICOS Y METEOROLOGICOS QUE AFECTAN AL ...

Ciencia & Desarrollo, 2020

En Juriquilla-Querétaro, se midió la concentración en masa de carbono negro (BC), la relación de ... more En Juriquilla-Querétaro, se midió la concentración en masa de carbono negro (BC), la relación de mezcla de monóxido de carbono (CO) y el dióxido de carbono (CO2). Las mediciones se realizaron del 01 de marzo al 30 de abril de 2016. En abril, los valores medios del BC (1.23 µg/m3) y CO (0.30 ppm) fueron mayores a sus correspondientes del mes de marzo (1.08 µg/m3 y 0.26 ppm, respetivamente). El CO2 no sufrió variación en estos meses y mantuvo un valor casi constante de alrededor de 406 ppm. Las tendencias diarias del BC, CO y CO2 fueron similares, con un máximo pronunciado por la mañana y un mínimo por la tarde. Estos contaminantes alcanzaron su valor máximo alrededor de las 08:00-09:00 Hora Local (HL). Se presentó una buena correlación en el ajuste lineal de BC-CO, BC-CO2 y CO-CO2, lo que sugiere que estos contaminantes provendrían de las mismas fuentes. Se observó un efecto fin de semana (valores más bajos del BC, CO y CO2 el fin de semana en comparación con los de días laborables),...

The photolytic rate constant of nitrogen dioxide is a key parameter in air quality models. We pre... more The photolytic rate constant of nitrogen dioxide is a key parameter in air quality models. We present the first actual measurements of this rate constant in Mexico City. These were obtained with the use of an actinometer and the reactor, where a known concentration of NO, was photolysed for different experimental exposure times. Under the given experimental conditions, photolysis constants for NO? were determined during the day. This experiment is the first of its kind in Mexico.

Urban Climate, 2021

Abstract Black carbon (BC), carbon monoxide (CO), and carbon dioxide (CO2) were measured in Mexic... more Abstract Black carbon (BC), carbon monoxide (CO), and carbon dioxide (CO2) were measured in Mexico City (UNAM observatory) with a Photoacoustic Extinctiometer-PAX (BC) and a Cavity Ring-Down Spectroscopy analyzer-CRDS (CO and CO2), from November 2014 to July 2016. The objective of this study was to determine temporal variations of BC, CO, and CO2, their mutual correlations, and evaluation of the Mexico City emission inventory. The highest concentrations of pollutants were detected in cold dry season. The average concentrations of BC, CO, and CO2, for the entire period, were 2.95 μg m−3, 0.64 ppm, and 421.81 ppm, respectively. We calculated ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2 using three methods to obtain a confidence interval for the emission ratios. BC, CO, CO2 concentrations, and the ΔBC/ΔCO ratio were maximum in the early morning, while the ΔBC/ΔCO2 and ΔCO/ΔCO2 peak was maximum in the afternoon. BC and CO have a weekday/weekend difference. The estimated slopes (ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2) were compared with the emission ratios (BC/CO, BC/CO2, and CO/CO2) derived of the 2016 Mexico City emissions inventory. For mobile sources, the emission ratios of BC/CO and BC/CO2 were within the measurement range of ΔBC/ΔCO and ΔBC/ΔCO2, while CO/CO2 was underestimated in the emission inventory.

Atmospheric Pollution Research, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Me... more We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Mexico City. To estimate the spectral irradiance needed in the calculations, the equation of transfer is solved by the delta-Eddington method. An atmosphere of air, nitrogen dioxide, ozone and dry aerosol is modeled. INTRODUCTION A state-of-the art photochemical kinetics model requires the specification of time-dependant rates for the two most important photolytic reactions: NO + hy > NO + 0 (1) 0 + hv > 0 + 0(*D) (2) Transactions on Ecology and the Environment vol 1, © 1993 WIT Press, www.witpress.com, ISSN 1743-3541 324 Air Pollution These reactions take place in different portions of the solar spectrum from 280 nm to 410 nm. Indeed, reaction (2) take place below 340 nm whereas nitrogen dioxide is photolyzed mostly above 340 nm. Photolysis of nitrogen dioxide is the key reaction in photochemical smog. It plays a fundamental role as the sole immediate precursor for tropospheric ozon...

We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Me... more We report theoretical photolysis rates for the nitrogen dioxide and ozone in the atmosphere of Mexico City. To estimate the spectral irradiance needed in the calculations, the equation of transfer is solved by the delta-Eddington method. An atmosphere of air, nitrogen dioxide, ozone and dry aerosol is modeled. INTRODUCTION A state-of-the art photochemical kinetics model requires the specification of time-dependant rates for the two most important photolytic reactions: NO + hy > NO + 0 (1) 0 + hv > 0 + 0(*D) (2) Transactions on Ecology and the Environment vol 1, © 1993 WIT Press, www.witpress.com, ISSN 1743-3541 324 Air Pollution These reactions take place in different portions of the solar spectrum from 280 nm to 410 nm. Indeed, reaction (2) take place below 340 nm whereas nitrogen dioxide is photolyzed mostly above 340 nm. Photolysis of nitrogen dioxide is the key reaction in photochemical smog. It plays a fundamental role as the sole immediate precursor for tropospheric ozon...

EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS ... more EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS NUEVAS ESTACIONES EN SITIOS M S ADECUADOS, AFIRMO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. CALIFICO DE ARBITRARIA LA LOCALIZACION DE LA RED ACTUAL. ALGUNAS ESTACIONES CERCA UNA DE LA OTRA, Y EN DELEGACIONES COMO XOCHIMILCO, MILPA ALTA Y CUAJIMALPA NO SE CUENTA CON MONITOREOS APROPIADOS, POR LO CUAL LA LOCALIZACION DE LAS NUEVAS INSTALACIONES DE LA RED DEBE HACERSE CON BASE EN UN ESTUDIO. RECONOCIO EL ESFUERZO DEL GOBIERNO DE LA CIUDAD PARA AMPLIAR LA RED DE MEDICIONES Y COMPLEMENTAR LAS QUE ACTUALMENTE EXISTEN CON M S SENSORES DE EVALUACION DE DIFERENTES CONTAMINANTES; EN LA ACTUALIDAD, HAY UN GRAN INTENTO POR MEDIR PARTICULAS DE 2.5 MICRAS, ANADIO. LA ESPECIALISTA INDICO QUE LAS PRINCIPALES EMISIONES CONTAMINANTES PROVIENEN DE LOS TUBOS DE ESCAPE DE LOS AUTOMOTORES, CUYA SOLUCION NO SOLO DEPENDE DE UNA DECISION POLITICA, SINO TAMBIEN CORRESPONDE A LOS CIUDADANOS FOMENTAR LA...

EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS ... more EN LA CIUDAD DE MEXICO SE REQUIERE AMPLIAR LA RED AUTOM TICA DE MONITOREO AMBIENTAL Y UBICAR LAS NUEVAS ESTACIONES EN SITIOS M S ADECUADOS, AFIRMO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. CALIFICO DE ARBITRARIA LA LOCALIZACION DE LA RED ACTUAL. ALGUNAS ESTACIONES CERCA UNA DE LA OTRA, Y EN DELEGACIONES COMO XOCHIMILCO, MILPA ALTA Y CUAJIMALPA NO SE CUENTA CON MONITOREOS APROPIADOS, POR LO CUAL LA LOCALIZACION DE LAS NUEVAS INSTALACIONES DE LA RED DEBE HACERSE CON BASE EN UN ESTUDIO. RECONOCIO EL ESFUERZO DEL GOBIERNO DE LA CIUDAD PARA AMPLIAR LA RED DE MEDICIONES Y COMPLEMENTAR LAS QUE ACTUALMENTE EXISTEN CON M S SENSORES DE EVALUACION DE DIFERENTES CONTAMINANTES; EN LA ACTUALIDAD, HAY UN GRAN INTENTO POR MEDIR PARTICULAS DE 2.5 MICRAS, ANADIO. LA ESPECIALISTA INDICO QUE LAS PRINCIPALES EMISIONES CONTAMINANTES PROVIENEN DE LOS TUBOS DE ESCAPE DE LOS AUTOMOTORES, CUYA SOLUCION NO SOLO DEPENDE DE UNA DECISION POLITICA, SINO TAMBIEN CORRESPONDE A LOS CIUDADANOS FOMENTAR LA...

Atmospheric Environment, 2016

PM 2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijua... more PM 2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijuana during the Cal-Mex campaign from May 24 to June 5, 2010. Concentration of trace elements (Mg,

Atmospheric Environment, 2018

The role of the Tenango del Aire mountain pass, located southeast of the Mexico City Metropolitan... more The role of the Tenango del Aire mountain pass, located southeast of the Mexico City Metropolitan Area (MCMA), in venting the city's air pollution has already been studied from a meteorological standpoint. To better understand the transport of gaseous air pollutants through the Tenango del Aire Pass (TAP), and its influence on the air quality of the MCMA, three mobile air quality monitoring units were deployed during a 31-day field campaign between February and March of 2011. Surface O 3 , NO x , and meteorological variables were continuously measured at the three sites. Vertical profiles of O 3 and meteorological variables were also obtained at one of the sites using a tethered balloon. Days were classified as being under low pressure synoptic systems (LPS, 13 days), high pressure synoptic systems (HPS, 13 days), or as transition days (TR). The Mexican ozone standards at the Pass were not exceeded during LPS days, but were exceeded on almost all HPS days. A detailed analysis was performed using data from two typical days, one representative of LPS and the other of HPS. In both cases, morning vertical profiles of O 3 showed a strong thermal inversion layer and near-surface O 3 titration due to fresh NO x. In the LPS early morning, a single O 3 layer of close to 45 ppb

Atmosphere, 2022

Black carbon (BC), a component of carbonaceous material, has an important role in the environment... more Black carbon (BC), a component of carbonaceous material, has an important role in the environment, and it is considered a short-lived climate forcer that plays a vital role in the global climate system. BC concentrations were analyzed during 2017 in two sites in Mexico, Juriquilla and Altzomoni, which have different emission sources and atmospheric dynamics. The annual average BC concentrations in 2017 were 0.84 ± 0.70 and 0.58 ± 0.37 µg m−3 for Juriquilla and Altzomoni, respectively. The principal contributors for the highest BC concentration in Juriquilla were anthropogenic sources, while pollutants transport from nearby cities was more important for Altzomoni. Comparison between this analysis and previous reports from 2015 for both sampling sites demonstrated an increase in BC concentration. Results of this study could contribute to a better understanding of BC effects under different emission conditions and provide a scientific reference for developing BC reduction strategies ov...

TELMA GLORIA CASTRO ROMERO FUE DESIGNADA DIRECTORA DEL CENTRO DE CIENCIAS DE LA ATMOSFERA (CCA) D... more TELMA GLORIA CASTRO ROMERO FUE DESIGNADA DIRECTORA DEL CENTRO DE CIENCIAS DE LA ATMOSFERA (CCA) DE ESTA CASA DE ESTUDIOS, POR LOS PROXIMOS CUATRO ANOS (2013-2017).

EL AIRE ES UNO DE LOS ELEMENTOS B SICOS PARA LA SOBREVIVENCIA DE LOS SERES VIVOS, POR ELLO ES FUN... more EL AIRE ES UNO DE LOS ELEMENTOS B SICOS PARA LA SOBREVIVENCIA DE LOS SERES VIVOS, POR ELLO ES FUNDAMENTAL ESTUDIAR LOS PROBLEMAS RELACIONADOS CON SU DIN MICA EN LA ATMOSFERA, EN PARTICULAR SU CONTAMINACION Y COMPUESTOS QUE DETERMINAN LA CALIDAD DEL AIRE, ASEGURO TELMA CASTRO, DEL CENTRO DE CIENCIAS DE LA ATMOSFERA. AL PRESENTAR LA CONFERENCIA ATMOSFERA SIN FRONTERAS, COMO PARTE DEL PROGRAMA EDUCATIVO DEL PROYECTO MILAGRO (MEGACITY INITIATIVE: LOCAL AND GLOBAL RESEARCH OBSERVATIONS), SENALO QUE DESDE TIEMPOS REMOTOS EL HOMBRE ES CONSCIENTE DEL PELIGRO QUE REPRESENTA UNA ATMOSFERA CONTAMINADA, YA SEA POR UN FENOMENO NATURAL COMO UNA ERUPCION VOLC NICA O LA QUE OCASIONA EL HOMBRE MISMO POR SUS ACTIVIDADES. RECORDO QUE LA ATMOSFERA ES UNA CAPA GASEOSA DE APROXIMADAMENTE 10 MIL KILOMETROS DE ESPESOR QUE RODEA LA LITOSFERA E HIDROSFERA. EST COMPUESTA DE GASES Y PARTICULAS SOLIDAS Y LIQUIDAS EN SUSPENSION. EN ELLA SE PRODUCEN TODOS LOS FENOMENOS CLIM TICOS Y METEOROLOGICOS QUE AFECTAN AL ...

Ciencia & Desarrollo, 2020

En Juriquilla-Querétaro, se midió la concentración en masa de carbono negro (BC), la relación de ... more En Juriquilla-Querétaro, se midió la concentración en masa de carbono negro (BC), la relación de mezcla de monóxido de carbono (CO) y el dióxido de carbono (CO2). Las mediciones se realizaron del 01 de marzo al 30 de abril de 2016. En abril, los valores medios del BC (1.23 µg/m3) y CO (0.30 ppm) fueron mayores a sus correspondientes del mes de marzo (1.08 µg/m3 y 0.26 ppm, respetivamente). El CO2 no sufrió variación en estos meses y mantuvo un valor casi constante de alrededor de 406 ppm. Las tendencias diarias del BC, CO y CO2 fueron similares, con un máximo pronunciado por la mañana y un mínimo por la tarde. Estos contaminantes alcanzaron su valor máximo alrededor de las 08:00-09:00 Hora Local (HL). Se presentó una buena correlación en el ajuste lineal de BC-CO, BC-CO2 y CO-CO2, lo que sugiere que estos contaminantes provendrían de las mismas fuentes. Se observó un efecto fin de semana (valores más bajos del BC, CO y CO2 el fin de semana en comparación con los de días laborables),...

Optical properties of atmospheric particles at Mexico City (UNAM) and Queretaro (JQRO) were measu... more Optical properties of atmospheric particles at Mexico City (UNAM) and Queretaro (JQRO) were measured with a Photoacoustic Extinctiometer (PAX) at 870 nm. The Mexico City Metropolitan Area has around 21 million inhabitants and Queretaro Metropolitan Area has little more than a million. Observations of meteorological parameters (relative humidity, solar radiation, and wind speed) were used to identify the rainy and dry seasons and explain the daily and seasonal behaviors of particles optical properties. The measurements were made from November 1, 2014 to July 31, 2016. At UNAM, the mean values of the scattering coefficient (B scat) in cold dry, warm dry, and rainy seasons were 35.8, 27.1, and 31.3 Mm −1 , respectively; while at JQRO were 10.9, 11.9, and 15.0 Mm −1. The average values of the absorption coefficient (B abs) at UNAM during the cold dry, warm dry, and rainy seasons were 14.5, 12.7, and 12.7 Mm −1 , respectively; whereas at JQRO were 4.9, 4.7, and 3.9 Mm −1. Both absorption and scattering coefficients showed similar diurnal behaviors, but at UNAM they are three times higher than JQRO. Concentrations of criteria gases (O 3 , NO, NO 2 and NO x) were also measured. At UNAM no difference was observed between the seasonal values for the single scattering albedo (SSA); while in JQRO, the rainy season had the highest seasonal value, being 13% higher than in the dry seasons. The Mass Scattering Cross-Section (MSC) values at UNAM were close to 2 m 2 /g; on the other hand, at JQRO the MSC values were lower than 1 m 2 /g. The results suggest a seasonal variability in the aerosol optical properties in both sites, which should be verified with more long-term studies.