Sugarcane cultivation is an agricultural activity of worldwide importance. This crop has been cultivated in Mexico for centuries, impacting important productive areas like the study region called Huasteca Potosina which is located at the Central-East part of Mexico. The relationship between soil conditions, weather and production per hectare allows identifying the edaphological and climatic conditions (aptitude levels) for cultivating sugarcane in the study area. The objective of this research work is to analyze the relation between the cultivated hectares and production of sugarcane. Likewise, to explain its behavior and interpret the contribution of N and C released to the atmosphere for burning sugar cane in association with events and meteorological parameters involved in the flux of water between soil and atmosphere such as drought, evapotranspiration and rainfall. The methods and indicators for burning waste provided by the Intergovernmental Panel on Climate Change (IPCC), the value of potential evapotranspiration as Thornthwaite and drought severity index were applied in order to understand the correlations between the drought severity index and potential evapotranspiration, and between C and N release and potential rainfall availability. The results show the increment of harvested hectares and the loss of water from the soil by the increase of periods of drought events and evapotranspiration. The volatilized nutrients in soil varied from 1.32 × 10 5 to 2.17 × 10 5 t for C and from 1.32 × 10 3 t to 2.17 × 10 3 t for N during the burning of sugarcane, affecting production levels with values fluctuating between 38 t/ha to 77 t/ha for the term of 1990-2010. Palabras clave: calidad del suelo, eventos meteorológicos, quema de residuos, flujo de agua Rev. Int. Contam. Ambie. 32 (2) 177-189, 2016 DOI: 10.20937/RICA.2016 D.E. Flores-Jiménez et al. 178 RESUMENEl cultivo de caña de azúcar es una actividad agrícola de importancia mundial llevada a cabo en México durante siglos, impactando importantes áreas productivas como la región de estudio llamada Huasteca Potosina, localizada al este central de México. La relación entre las condiciones del suelo, clima y producción por hectárea permite identificar las condiciones edafológicas y climáticas (niveles de aptitud) para cultivar la caña de azúcar en el área de estudio. Bajo este contexto, el objetivo fue analizar la relación entre las hectáreas cultivadas y la producción de caña de azúcar y explicar su comportamiento al interpretar las contribuciones del N y C liberados a la atmósfera por la quema de caña asociados a eventos y parámetros meteorológicos involucrados en el flujo de agua entre el suelo y la atmósfera como sequía, evapotranspiración y lluvia. Los métodos e indicadores para la quema de residuos provistos por el Panel Intergubernamental del Cambio Climático (IPCC, por sus siglas en inglés), el valor de la evapotranspiración potencial por Thornthwaite y el índice de severidad de la sequía fueron aplicados para comprender las correlaciones entre...

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The objective was to analyze how representative tropospheric NO 2 column densities are of surface NO 2 measurements under different atmospheric stability conditions in the air basin of two border cities: Calexico, United States, and Mexicali, Mexico. NO 2 columns were measured by the Ozone Monitoring Instrument (OMI) on the NASA Aura satellite. NO 2 concentrations and meteorological parameters were also measured on the surface for comparison. Specifically, the correlations between OMI and surface NO 2 concentrations under different atmospheric stability conditions according to the Pasquill-Gifford (P-G) and Monin-Obukhov (M-O) classification schemes were determined for 2017 and 2018. During the passage of the satellite through the study area (11:00-13:00 UTC−8), unstable conditions were documented in both years.Good correlation was found between the surface NO 2 and OMI NO 2 column observations in the second semester of each year, particularly under unstable conditions as diagnosed by the P-G and M-O schemes applied in the first and second year, respectively. However, a weakening of these conditions occurs during the autumn-winter period. In both cases, the highest determination coefficients were found for Calexico, with values of 0.48 and 0.36 in 2017 and 2018, respectively; for Mexicali, the determination coefficients were 0.23 and 0.35, respectively. Under each atmospheric stability scheme, the mechanical and convective turbulence caused a decreasing trend in wind speed and solar radiation over the course of second semester of 2017 and in friction velocity, temperature, and sensible heat flux over the course of the same period for 2018. The negative trend of these parameters during the analyzed time frames helped to reduce the influence of unstable atmospheric conditions, favoring better correlations between satellite and surface NO 2 measurements. The methodology applied and results obtained herein can enable us to better understand the representativeness of OMI NO 2 data in arid border zones with extreme meteorological conditions.

México es un país vulnerable a los eventos climáticos extremos; sin embargo, el impacto no es uniforme en todo el territorio, por lo que se analizan y modelan las temperaturas extremas de 12 ciudades de México con la suposición de que existe un clima no estacionario en todas las regiones del país. A partir de la base climatológica disponible de temperaturas máximas y temperaturas mínimas, se estimó una tendencia temporal con las pruebas no paramétricas de Mann-Kendall y el método de pendiente de Sen, y se utilizó la distribución generalizada de valores extremos (GEV) para modelar ambas temperaturas. Para evaluar la fortaleza de los modelos propuestos con la incorporación de una covariable, se utilizaron tanto la prueba de razón de verosimilitud como los criterios de información de Akaike y de Bayes, y se estimaron los niveles de retorno para escenarios temporales futuros. Se detectó una tendencia al calentamiento urbano, tanto con las pruebas no paramétricas como con la distribución GEV, aunque con comportamiento heterogéneo. En la serie de temperatura máxima, la mitad de las ciudades analizadas se mostró no estacionaria; de éstas, la ciudad de Guadalajara, situada en el centro-occidente del país, presentó tendencia negativa. En el caso de las temperaturas mínimas la tendencia fue más uniforme: 90% de las ciudades se mostraron no estacionarias con tendencia positiva y sólo el 10% (una zona urbana al oriente de la zona metropolitana del Valle de México [Milpa Alta] y una ciudad costera del Golfo de México [Veracruz]) mostraron una serie estacionaria. Se concluye que los periodos de retorno de extremos térmicos estimados en un clima cambiante varían temporalmente, por lo que la modelación estadística debe tomar en cuenta ese comportamiento en razón de su importancia para valoraciones de riesgos y propósitos de adaptación.

In the present work, due to the importance of the dispersion of pollutants in the air, the modified Pasquill-Gifford classification was used to determine the classes of atmospheric stability, which serve to indirectly identify the increase or decrease of the existing mechanical and convective turbulence, conditions that at the same time affect the dispersion of pollutants; the above was carried out in the municipality of Zacatecas in the years of 2019 and 2020; the data of concentrations of Carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOX), PM10 and PM2.5 particles, and ozone (O3) released from a monitoring station and were contrasted with the estimated atmospheric stability classes in order to observe the influence of these classes on these pollutants; and finally, based on the results obtained, it was identified in which seasons of the year there is a greater and lesser dispersion of pollutants. Once this process was carried out, a series of recommendations were issued about the feasibility of using this classification in the city of Zacatecas. Maximum frequencies of class A were obtained between 9:00 and 12:00 hours, considered the most unstable with 52.22% for spring, 53.57% for summer, 44.87% for autumn, and 40% for winter. When class A increased its frequency, the concentration of particles decreased, and when class F increased, the concentration of particles increased. Therefore, it is recommended to consider different factors that may influence the dispersion of pollutants in the city of Zacatecas and, regarding the results obtained, make use of this classification only in hourly averages. Likewise, the Pasquill-Gifford classification could be combined with atmospheric models to determine the behavior of particles in different periods with greater confidence.