Atmósfera (Journal)
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Climate variability over the reef corridor of the southwestern Gulf of Mexico
Get PDFLocal and regional climate trends drive rates of change in coastal ecosystems. To better understand local climate, 35-year-long time series of air temperature, relative humidity and rainfall were analyzed along the reef corridor of the southwestern Gulf of Mexico. Data came from a climatological model and to assess its local performance, differences with in situ records were estimated when available. All three variables showed coherence with the record of the North Atlantic high-pressure system (also known as the Bermuda High) at similar times and periods between 4 to 8 and >10 years, evidencing the influence, at this regional scale, of El Niño Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO). Positive and negative anomalies showed linear trends depicting an increase of warmer and moister events during a seasonal climatology at the reef corridor of the southwestern Gulf of Mexico and a relatively higher correlation (> 0.5) with the AMO mode. Return periods of extreme values varied between 5 and 10 years. In general, trends and extreme events showed similar patterns at a regional scale, but the increase in rainfall is expected to be larger near the central location of the study area. A higher frequency of extreme events could threaten local ecosystems and human populations; therefore, plans and actions at local scales of governance are needed to achieve preemptive climate adaptation.
Impact of fossil fuels, renewable energy consumption and industrial growth on carbon emissions in Latin American and Caribbean economies
Get PDFThis study examines the impact of fossil fuels consumption, renewable energy use and industrial growth on carbon emissions in the developing economies of Latin America and the Caribbean. An industrial growth index is developed using competitive industrial indicators, and a two-step system generalized method of moments robust estimator is employed, involving a panel of 16 middle- and lower-middle-income economies for the period 1990 to 2015. The empirical results show an Inverted-U shaped relationship between economic growth and carbon emissions and confirm the existence of the environmental Kuznets curve for the region. The results indicate that industrial growth and consumption of fossil fuels are significantly contributing to carbon emissions in the region. The results highlight that, based on competitiveness in manufacturing and the transition from simple to sophisticated technologies, advance technology-based industrial growth increases the potential to produce goods competitively with lower carbon emissions. The findings suggest that such advanced industrial growth is unavoidable to attain sustainable economic growth. Thus, technological advancement and consumption of renewable energies have the potential to both meet the rising demand for goods and energy and to control carbon emissions in the developing countries of Latin America and the Caribbean
Building adaptation to extreme rain effects in San Francisco de Campeche, Mexico (edited by Dr. Christian Appendini)
No full textAn integrated coastal zone management approach was used towards building adaptation strategies for the city of San Francisco de Campeche, Mexico. Large interannual variability in precipitation extremes have led to city-wide flooding in numerous occasions, threatening the population and city infrastructure. A special steering committee was appointed to coordinate an integrated coastal management plan within the three levels of government (federal, state and municipal) and to review the legal framework for water management. The municipal administration designed the blueprint for the project and an associated environmental education campaign. A pluvial drainage system was built to separate pluvial from domestic wastewater. Moreover, the wastewater drainage system was strengthened, and the city water treatment plants improved. As a result, water quality in the coastal zone improved and the city of San Francisco de Campeche was able to build its plan for adaptation to extreme rain events, which are increasingly frequent due to climate change
Trend estimation and forecasting of atmospheric pollutants in the Mexico City Metropolitan Area through a non-parametric perspective
Get PDFTrends and forecasts of the main atmospheric pollutants (O3, SO2, NO2, CO, PM10, PM2.5, NO and NOx) are estimated by regions in the Mexico City Metropolitan Area (MCMA) with maximum daily data from 2008 to 2018. A non-parametric statistical smoothing controlled technique based on the Hodrick and Prescott filter and estimated through the Kalman filter, is used. Both point and interval estimates, as well as their respective forecasts are generated. Estimates are compared against the environmental standard for Mexico City (NADF-009-AIRE-2017), and it is evident that, in general, they are still distant from good air quality in the MCMA, as opposed to CO and NO2. The remaining pollutants have trends and forecasts that are far from the permissible limits
Climatic variation in the high mountains of central Mexico: Temperature and precipitation indices at Nevado de Toluca volcano
Get PDFThe Nevado de Toluca weather station (4283 masl, 19 ºN) has recorded meteorological data for over half a century, and this combination of elevation and duration provides a rare opportunity to study climate trends in a tropical high-mountain environment. The climatic variability during the period 1965-2015 at the Nevado de Toluca volcano was analyzed. Nine standard climate indices for temperature and seven for precipitation were calculated from daily data from its weather station. The results, with a high level of statistical significance, show an increase in the number of days with night frost and cold periods; likewise, results indicate an increase in the diurnal thermal oscillation. Total accumulated precipitation shows an increasing tendency over time, although the periods with precipitation are increasingly isolated. This suggests that seasonal snow on the summit of the volcano will be increasingly isolated but, at the same time, the snowpack will persist longer. This work is expected to serve as a reference for other high-mountain tropical environmental studies, where air temperature and precipitation are crucial issues.The Nevado de Toluca weather station (4283 masl, 19 ºN) has recorded meteorological data for over half a century, and this combination of elevation and duration provides a rare opportunity to study climate trends in a tropical high-mountain environment. The climatic variability during the period 1965-2015 at the Nevado de Toluca volcano was analyzed. Nine standard climate indices for temperature and seven for precipitation were calculated from daily data from its weather station. The results, with a high level of statistical significance, show an increase in the number of days with night frost and cold periods; likewise, results indicate an increase in the diurnal thermal oscillation. Total accumulated precipitation shows an increasing tendency over time, although the periods with precipitation are increasingly isolated. This suggests that seasonal snow on the summit of the volcano will be increasingly isolated but, at the same time, the snowpack will persist longer. This work is expected to serve as a reference for other high-mountain tropical environmental studies, where air temperature and precipitation are crucial issues
Typhoon Haikui induced sea surface temperature cooling and rainfall influence over Zhejiang coastal waters
Get PDFStrong winds in typhoons cause upwelling/mixing of seawater and hence a reduction in sea surface temperature (SST). The SST cooling depends on the intensity and translation speed of the typhoon. In this paper, typhoon Haikui’s induced SST cooling was analyzed with satellite-derived data. Haikui produced SST cooling on both sides of the track: the right-side cooling was due to upwelling/mixing (which depend upon the intensity of the typhoon), and rainfall induced SST cooling on the left side. Typhoon Haikui induced SST cooling over the coastal region was found to be about 1.9 ºC due to lower translation speed leading to upwelling, and also due to rainfall. The spatial extent of the cooler SST increased after the typhoon made landfall, especially over coastal regions. SST cooling over the study area has an inverse relation both to the typhoon’s translation speed and to rainfall. Due to heavy rainfall and air-sea interaction processes, SST cooling was higher on coastal waters, and cool waters persisted for a few days after the typhoon landfall
Evapotranspiration flux partitioning at a multi-species shrubland with stable isotopes of soil, plant, and atmosphere water pools
Get PDFEvapotranspiration is the second largest component of the hydrological cycle after rainfall precipitation in semiarid regions such as northwestern Mexico. In this study, we partitioned the evapotranspiration (ET) flux using stable isotopes of water in the soil-plant-atmosphere continuum in combination with eddy covariance flux measurements. We considered three methods for determining the isotopic composition of transpiration (δT): (1) isotopic steady state, (2) non-steady state, and (3) non-steady state weighting the relative importance of dominant species cover and accounting for the relative values of stomatal conductance. Three approaches of T/ET partitioning were estimated during several wet and dry days at the study site in Sonora, Mexico. The total ET flux was variable across years due to differences in precipitation amount between years. ET was lower during the drier-year and reached higher values during the wetter-year. Soil evaporation (E) dominated ET soon after large rain events (40 to 70 mm d–1 [DOY-196 and DOY-197] in 2008) but showed a rapid decrease in dominance as the soil surface dried. Estimated values of T/ET based on an isotopic mass balance were in the same range independent of three methods used. The mean T/ET ratio across all the periods studied was in the range of other studies in semiarid ecosystems and global trends with values of ~0.67 ± 0.02. This work contributes to a better understanding of the surface atmosphere interactions in semi-arid regions
Preliminary study of soot and polycyclic aromatic hydrocarbons in emitted particles from adobe kilns that use scrap tires as fuel
Get PDFArtisanal pottery in Mexico is largely manufactured in handmade adobe kilns using scrap tires as main fuel in rural and periurban areas, making this activity one of the main sources of atmospheric pollutants. An intensive sampling campaign was conducted in a Mexican small town in order to characterize the toxic species emitted by more than 400 adobe kilns working in two scenarios: low and normal activity, as well as to determine their carcinogenic potential. PM10 concentrations ranged 50-80 µg m−3 and 77-290 µg m−3 during low and normal activity periods, while PM2.5 concentrations were 33-57 µg m−3 and 37-177 µg m−3 in the same periods. Organic carbon and elemental carbon presented concentrations around four and seven times greater, respectively, during a normal activity period than during a low activity period in both particle sizes. Quantified polycyclic aromatic hydrocarbons were twice greater during the normal activity period than during the low activity period. Carcinogenic PAHs accounted for 53-59% of total PAHs in all cases and the carcinogenic potential (B[a]Peq) in PM10 during the normal activity was 25 times higher than the European Commission recommendation, proving thereby the high risk that nearby population faces to those emissions
Study of the dispersion of AGI emitted from ground-based generators using the WRF-Chem model
Get PDFIn studies of cloud seeding by ground-based generators, a dispersion analysis of the silver iodide (AgI) glaciogenic aerosol is a necessary tool to estimate if it reaches seeding heights. A study of the dispersion of AgI emitted by a network of generators with hypothetical locations in the eastern region of Cuba was developed using the WRF-Chem model. Two spatial distributions with different heights and distances between generators were analyzed. Two experiments were undertaken with emission rates of 10 and 30 g h–1, based on a sample of six days. The activation level was not reached for an emission rate of 10 g h–1, while for 30 g h–1 static seeding could occur but the area with seeding aerosol was not significant. The distribution in which generators were closer together turned out to be the one with smaller maximum concentrations and bigger areas occupied by the aerosol at a given level. Covered area and seeding aerosol concentrations increased for emission rates of 30 g h–1. In general, the plume follows the wind direction and its vertical rise is determined by the turbulent kinetic energy for the area where the generator is placed
Parametric study of hurricanes intensity as they move over land
Get PDFTwo of the most important tropical cyclone parameters, which are used as a measure of their intensity, are the maximum surface wind speed (local parameter) and the pressure difference between the free atmosphere and the pressure in the center of the storm (global parameter). In this paper we reexamined the relationship between these parameters via the Euler number, which is a nondimensional parameter that relates the overall pressure difference to the dynamic pressure generated by the maximum value of the wind speed. The calculations were performed all along the track of 20 tropical cyclones using the National Hurricane Center’s extended best track database for the Atlantic basin. It was found that when the cyclone is over water, the Euler number tends to remain constant, while over land the parameter varies drastically with a tendency to grow. These results confirm that over sea, when they have reached hurricane strength, tropical cyclones evolve slowly remaining near the steady state, highlighting the importance of transient states during strong dissipation. The Euler number seems to be independent of the global warming