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Since 2008, automatic, multiple assessment options have been utilised in selected undergraduate meteorology courses at the University of Wisconsin--Milwaukee. Motivated by a desire to reduce stress among students, the assessment methodology includes examination-heavy and homework-heavy alternatives, differing by an adjustable 15% of the overall course grade. Students do not need to commit "a priori" to one particular assessment option, as the more beneficial of two alternative assessment schemes is automatically chosen at the end of the semester. An analysis of assessment score differences reveals that end-of-semester assessments increased by more than 1% for 48% of the students enrolled, a consequential increase which can improve a student's assessment by a fractional grade. Score differences among the two assessment alternatives tend to be smaller for higher achieving students, and larger for the middle- and lower achieving students. Score differences larger than 3% were rare. Limited survey results indicate that students understand and appreciate the assessment scheme, and feel that it reduces stress and may improve their academic performance. The automatic, multiple assessment methodology presents no risk to either student or instructor, as students can only benefit and virtually no effort is required of the instructor.

Fine particulate matter (PM2.5) from fireworks displays have been linked to serious health concerns, particularly in infants and children. Outdoor displays in large, recurring festivals such as state fairs thus may threaten local air quality, particularly given the proximity of fairgrounds to substantial, nearby residential populations. Here, we identify state fairs with known firework displays and assess their impact on air quality in nearby communities. We assessed the impact of three large, recurring festivals on PM2.5 levels in nearby communities. Overall, our multi-year analysis failed to identify measurable increases in PM2.5 concentrations during festival days at air quality monitoring sites within 4–10 km of the fairgrounds, even when data were filtered by wind direction. Results suggest that firework displays from such festivals are unlikely to violate PM2.5 air quality standards in communities near the fairgrounds. The results suggest that identifying a potential air pollution signal associated with fireworks is challenging, particularly in urban fairgrounds where air quality is impacted by multiple local and distant pollution sources. Local impacts may yet be identified in future studies if air quality is monitored closer to the fairgrounds and if the fireworks pyrotechnic content is known. [ABSTRACT FROM AUTHOR]

In this work, we identify the current atmospheric sulfur dioxide emissions of the Veracruz port, an important Mexican seaport experiencing rapid growth, and its influence on the surrounding areas. Sulfur dioxide emissions based on port activity, as well as meteorology and air quality simulations, are used to assess the impact. It was found that using marine fuel with low sulfur content reduces emissions by 88%. Atmospheric emission estimates based on the bottom-up methodology range from 3 to 7 Mg/year and can negatively impact air quality up to 3 km downwind. After evaluating different characteristics of vessels in CALPUFF, it was found that maximum sulfur dioxide concentrations ranging between 50 and 88 µg/m3 for a 24-h average occurred 500 m from the port. During 2019, five days had unsatisfactory air quality. The combination of a shallow planetary boundary layer, low wind speed, and large atmospheric emissions significantly degraded local air quality. [ABSTRACT FROM AUTHOR]

Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few centuries of acid rain is sufficient to destroy paintings, frescoes, and other fine detail in ancient art and architecture. This article describes an interdisciplinary educational supplement designed for middle-and high-school classrooms called "Acid Thunder: Saving El Tajin from Acid Rain." This supplement came about as a result of research conducted by the University of Wisconsin-Milwaukee in collaboration with the National Autonomous University of New Mexico (UNAM). The supplement is in the form of a Webquest, an inquiry-oriented exercise focusing on analysis, synthesis, and evaluation, for which the Internet is the primary information source. "Acid Thunder" is two-week activity that follows the work of a group of UNAM scientists who are researching many aspects of acid rain, including chemistry; meteorology; effects on plants, animals and materials; and measurement. "Acid Thunder focuses on the El Tajin archaeological zone, an important monument site in the state of Veracruz, Mexico. The Webquest is designed as an interdisciplinary unit to facilitate standards-based, active exploration in science and social studies. With "Acid Thunder", teachers have the significant opportunities to integrate topics in science and social studies and can offer students a stimulating experience likewise students can research features of an ancient Mesoamerican culture and compare it with other pre-Hispanic civilizations like the Mayas or Aztecs. In addition, this Webquest serves the important function of demonstrating to students how classroom walls are no longer a boundary for classroom-based activities. (Contains 2 figures.)

Atmospheric benzene and carbonyls were studied in San Nicolas de los Garza, Nuevo Leon, during 2011 and 2012. The relative abundance for measured VOCs was the following: formaldehyde (9.06 μg m.-3) > acetaldehyde (8.06 μg m.-3) > benzene (0.65 μg m.-3). All measured VOCs had a clear seasonal trend with higher values of concentration during summer. Benzene and formaldehyde had a marked diurnal trend with the highest levels during morning, whereas acetaldehyde did not show a clear diurnal pattern. Meteorological analysis showed that the dominant winds came from NNE and ENE, suggesting that sources located in these directions contribute to the VOC levels. Principal component analysis (PCA) analysis revealed that photochemical activity influenced benzene and carbonyl levels during summer and that benzene was associated with vehicular traffic emissions during autumn and winter, showing good correlation with CO. Meteorological data showed that measured VOCs were influenced by regional sources. A health risk assessment showed that local exposure to carbonyls and benzene exceeded 1 × 10-6 for integrated lifetime cancer risk. People living in San Nicolas de los Garza, thus, have a probable risk of suffering cancer in their lifetime. It is, therefore, necessary to improve environmental policies for controlling VOC levels in this area. [ABSTRACT FROM AUTHOR]

The article highlights the temporal behavior of particulate matter that is equal or less than 10 micrometer in aerodynamic diameter (PM10) in Mexico's Monterey Metropolitan Area (MMA). The authors used 2006-2008 data from the Sistema Integral de Monitoreo Ambiental network and compared the levels of PM10 by year, season and every day of each year. They found that the highest levels of PM10 was in southwest MMA and that winter was the most polluted season.

Abstract: A field study was carried out in the Metropolitan Area of Monterrey (MAM), the second most populated city in Mexico, characterized by increasing urbanization, high traffic density, and intense industrial activity. These characteristics commonly present high concentrations of air pollutants leading to the degradation of air quality. PM 2.5 was analyzed for heavy metals at two urban sites located within the MAM (Juarez and San Bernabe) in order to determine sources, health risk, morphology, and elemental content during the COVID-19 pandemic (autumn 2020 and spring 2021). Twenty-four-hour samples of PM 2.5 were collected at each site during 30-day periods using high-volume equipment. Gravimetric concentrations and 11 metals were measured (Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Ni, Cr, and Pb) by different analytical techniques (flame atomic absorption spectroscopy, graphite furnace atomic absorption spectroscopy, and inductively coupled plasma optical emission spectroscopy). Selected samples were analyzed by scanning electron microscopy-energy-disperse spectroscopy in order to characterize their morphology and elemental content. PM 2.5 concentrations exceeded the Mexican standard and WHO guidelines in Juarez during spring 2021. Cu, Cd, and Co were highly enriched by anthropogenic sources, and Ni, K, Cr, and Pb had a moderate enrichment. Mg, Mn, and Ca were of crustal origin. Bivariate statistics and PCA confirmed that alkaline metals originated from crustal sources and that the main sources of trace metals included traffic emissions, resuspension from soil/road dust, steel industry, smelting, and non-exhaust emissions at both sites. Lifetime cancer risk coefficients did not exceed the permissible levels established by EPA and WHO, implying that local residents are not at risk of developing cancer. Non-carcinogenic risk coefficients revealed that there is a possible risk of suffering cardiovascular and respiratory diseases due to inhalation of cobalt at the study sites., Supplementary Information: The online version contains supplementary material available at 10.1007/s11869-023-01372-7., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s), under exclusive licence to Springer Nature B.V. 2023, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Trajectory models are frequently used to characterize the atmospheric transport pathways for airborne gases and aerosols. Users of these models must specify a starting elevation for their calculations. The variation of wind with altitude causes trajectory models to be sensitive to the starting elevation, particularly when single trajectories rather than Lagrangian particle dispersion simulations are used to characterize atmospheric transport. In this work we systematically investigate and quantify the sensitivity of single trajectory calculations to the starting elevation. The analysis was based on an eight-year database of daily, 48-h back-trajectories calculated for ten sites. Trajectories were calculated at four different starting elevations, and the horizontal difference between endpoints was determined for five upwind travel times. Trajectory model calculations were found to be strongly sensitive to starting elevation. A 500 m difference in starting elevation leads to an average horizontal separation of 326 km after 48 h. Mean horizontal separations of 627 km and 886 km were found for starting elevation differences of 1000 m and 1500 m, respectively. A seasonal dependence of the sensitivity was found, with the smallest separations occurring during the summer, the largest during winter, and intermediate values during the fall and spring. A linear relationship was observed between trajectory model sensitivity and difference in starting elevation. Empirical equations were presented to approximate this relationship., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Air trajectory and particle scattering data (bsp) for the period 1984-1989 are used to determine the relationship between atmospheric transport and visual air quality at the Grand Canyon National Park. Using cluster analysis, 72-hour back-trajectories arriving four times per day were grouped into distinct transport patterns. Northwesterly and southerly/southwesterly flow dominate in the winter and summer seasons, respectively. Comparisons of bsp values accompanying different transport patterns showed a clear relationship between air flow pathway and light scattering due to small particles during the non-summer months only. An index is defined which describes the percentage of annual trajectories belonging to specific transport routes delivering predominantly clear air to the GCNP.