Showing papers on "Air quality index published in 1981"

Judging Air Quality Model Performance

Abstract: Under the direction of the AMS Steering Committee for the EPA Cooperative Agreement on air quality modeling, a small group of scientists was convened to review and recommend procedures to evaluate the performance of air quality models. Particular attention was paid to the operational use of models in regulatory settings. A number of general recommendations resulted from the workshop. The usefulness of models to aid decision makers in air quality management was reiterated. Concerns about the absolute, rather than the statistical, nature of air quality standards were raised, with a recommendation to reformulate standards accordingly. Model performance evaluation was suggested on the basis of differences between observed and predicted concentrations. The bias (average), the variance (noise), and the gross variability (gross error) of such differences were the recommended performance measures. In addition, correlation measures calculated in time, space, and jointly between observation and predictions...

Air pollution modeling and its application

Abstract: This volume seeks to cover the latest scientific developments in the field of air pollution modeling. It contains papers and posters presented at the 26th NATO/CCMS International Technical Meeting on Air Pollution Modelling and Its Application held in Istanbul Technical University, Turkey, May 2003. Major topics covered include: the role of atmospheric models in air pollution policy and abatement strategies (air quality, risk assessment, emergency responses). Integrated regional modelling (local and urban effects, mesoscale phenomena, regional modelling, one and two way nesting, application of existing models). Global and long-range transport (synoptic, hemispheric & global scales, application of existing models). Aerosols as atmospheric contaminants (human exposure and health effects, direct and indirect climate effects, visibility reduction). New developments (microscale to global scale, new models, new extensions to existing models, inverse modelling, data assimilation). Model assessment and verification (model assessment, design of field experiments, use of on-site meteorological data, limits to predictability). Applications of new concepts in different regions of the world are also presented. The domain of the modeling covers all geographical sizes from global down to regional, local, urban and canyon sizes.

Lichen recolonization following air quality improvement

Abstract: Air quality improvement near a coal-fired power plant led to recol- onization of Parmelia caperata (L.) Ach. in a pollution-induced void area. Recol- onization was first observed about four years after pollution abatement. Least- affected sites, i.e. near the edge of the original void, were first to recover while most-affected sites were slowest to recover. After eight years of improved air quality, the distribution of P. caperata has returned to near normal. Lichen bio- monitoring is useful not only to detect the effects of poor air quality but to docu- ment air quality improvement as well. There are numerous reports detailing the depauperate condition of lichens in polluted environments (Ferry et al. 1973). However, reports of lichen recovery following pollution abatement are almost nonexistent. This could be because repeating lichen work in a known area does not have the research appeal of new studies in an unknown area. It might also be because lichen recolonization is a relatively slow process. Henderson-Sellers and Sea- ward (1979) have followed the progress of Lecanora muralis (Schreb.) Rabenh. in an improved environment. They found a lag time of about five years before air quality im- provement was reflected by improved lichen distribution. Changes in fuels and industrial technology to meet strict emission standards have led to decreased air pollution levels in many areas. Information on lichen recolonization is valuable for interpreting lichen studies in those areas where pollution levels have decreased.

Sensitivity of a Complex Urban Air Quality Model to Input Data

Abstract: In recent years, urban-scale photochemical simulation models have been developed that are of practical value for predicting air quality and analyzing the impacts of alternative emission control strategies. Although the performance of some urban-scale models appears to be acceptable, the demanding data requirements of such models have prompted concern about the costs of data acquisition, which might be high enough to preclude use of photochemical models for many urban areas. To explore this issue, sensitivity studies with the Systems Applications, Inc. (SAI) Airshed Model, a grid-based time-dependent photochemical dispersion model, have been carried out for the Los Angeles basin. Reductions in the amount and quality of meteorological, air quality and emission data, as well as modifications of the model gridded structure, have been analyzed. This paper presents and interprets the results of 22 sensitivity studies. A sensitivity-uncertainty index is defined to rank input data needs for an urban phot...

The design of cost-effective air quality monitoring networks.

Abstract: A statistical measure of information content is used as a means for assessing the effectiveness of a particular monitoring network configuration. This measure is directly related to the precision with which the network can estimate the level of air quality in the region. Each potential site in the network can contribute to an increase in the overall precision of the estimate. The amount of increase is determined by the degree of dependence, displayed by observed pollutant concentrations, between potential sites.

Minimizing the cost of air pollution control

Abstract: A recent report by the Council on Environmental Quality (1979) places the cost of air pollution control in the US at $193 billion annually Cumulative abatement expenses are expected to total more than $300 billion over the decade ending in 1987 These high costs are coupled with an abatement program that has yet to achieve compliance with federal air quality standards (Table 1) There is mounting pressure to "solve" both the compliance and cost problems by relaxing air quality goals

Regional air pollution model for calculating short-term (daily) patterns and transfrontier exchanges of airborne sulfur in Europe

Abstract: An air pollution model, EURMAP-2, has been developed to simulate and assess the effects of daily variation in sulfur emissions on short-term (daily) air quality in central and western Europe. The model has been used to calculate daily concentrations, daily depositions, and daily transfrontier exchanges of SO 2 and SO 4 = during the episodes of August 25–26 and September 14–16, 1974. A comparison between model-calculated and measured concentrations of SO 2 and SO 4 shows a reasonably good agreement over large portions of the model grid, although calculated concentrations are lower than measured values in the eastern portion. Calculated patterns for dry SO 2 deposition show strong correlation with emissions; patterns for wet deposition correspond closely to natural inhomogeneities in precipitation. Discrepancies between model results and measurements are attributed to nonrepresentativeness of emissions data in the eastern portion of the model domain and the inability of the model to realistically incorporate the effects of complex terrain, vertical diffusion, transformation, and deposition rates. A comparison between the results of EURMAP-2 and the NILU (trajectory) model developed by the Norwegian Institute for Air Research shows some significant differences, perhaps a result of the different treatments of some physical elements in the two models. DOI: 10.1111/j.2153-3490.1981.tb01740.x

Lichens and Air Quality in Big Bend National Park, Texas

Abstract: This study was undertaken because of reports of decreased visibility due to haze and the possibility of increased air pollution in the park. Numerous localities where lichens had been collected 10 years ago were revisited in 1980 to look for any changes in the lichen flora. Photographs were taken from scenic vistas where photographs had been taken earlier. Permanent photographic points for lichens were established for long term monitoring. It is argued that fruticose li- chens are just as useful for monitoring air quality in arid areas as in wetter areas. There has been no loss of lichen species at any locality over the past 10 years and haze conditions have not changed much. It is concluded that no significant increase in air pollution has occurred within the park over the past 10 years. In 1966, 1969 and 1970, complete lichen collections were made at 38 localities in Big Bend National Park. Label data for all collections are stored in a computer data base at the University of Minnesota (Wetmore 1979) and a report on the macrolichens (foliose and fruticose lichens) from these localities has been published (Wetmore 1976). Even though the general climate in the park is quite dry, several species of fruticose lichens were found at numerous localities in the mountains. At the time these collections were made, color photographs were taken from various scenic vistas throughout the park. Recent observations by various people have reported the visibility in the park has been degraded due to increased haze conditions. There has also been concern that the haze might be associated with air pollutants that could damage the vegetation of the park. Possible sources of the air pollution are Carlsbad, New Mexico, and El Paso, Texas, These cities are about 400 km northwest of the park and wind patterns are such that air masses from these cities could blow into the park. Lichens are slow growing and remain alive for many years, and therefore can be used as long-term indicators of air quality. They are also known to be very sensitive to many atmospheric pollutants. Some lichens are damaged or killed by low levels of sulfur dioxide (0.5 ppm, Nash 1973), nitrogen oxides (2-4 ppm, Nash 1976) and other strongly oxidizing compounds (Nash 1972, 1975; Ferry et al. 1973). The algae of the thallus seem to be the

The Regulatory Approach to Air Quality Management: A Case Study of New Mexico

Abstract: In the wake of the Clean Air Amendments of 1970 in the United States, sources of emissions could be held accountable for the degradation of air quality in the local environment. This case study of air quality management in New Mexico was produced to shed some light on the procedures and activities used by agencies in order to control air quality. Originally published in 1981, Winston Harrington uses New Mexico as a case study for its largely centralised control system in Santa Fe to explore the behaviour of air quality agencies and pollution sources and comments on policy implications from this study’s conclusions. This title will be of interest to students of environmental studies and policy makers.

Spatial distributions of urban atmospheric particulate concentrations

Abstract: Although spatial variations in ambient air quality are important to human health and efforts to improve air quality, a historical lack of data has hampered spatial analysis of air quality The mapping of recent ambient atmospheric particulate monitoring data in ten urban areas reveals certain similarities, including concentric patterns and localized maxima and minima More detailed analyses utilizing a stratified random sampling of the concentration isopleths reveal two important conclusions First, existing monitoring data are not spatially representative, but rather tend to overestimate both average and extreme areawide concentrations Second, particulate concentrations are approximately lognormally distributed in space This latter result can be explained by distribution of areal land uses rather than by physical factors

Comparison Between Polluted and Clean Air Masses over Lake Michigan

Abstract: Clean and polluted air masses, advected over Lake Michigan, were studied using instrumented aircraft during the summers of 1976 and 1978. The results show that regardless of the degree of pollution, the particle size distribution is bimodal. The concentrations of sulfate, nitrate and trace metals in a clean air mass are more than an order of magnitude lower than those in polluted air masses. Furthermore, these concentrations are comparable with those measured in remote areas of the world. In clean air the ratio of the total light scattering to Rayleigh scattering is very close to one, indicating very low concentrations of particulates in the optically active size classes.

Health and Air Quality: Evaluating the Effects of Policy

Abstract: The authors present an economic analysis of the problems of air pollution and their economic implications. They offer a legislative history of attempts to control air pollution, and emphasize that recent improvements in air quality have resulted from older legislation with low-cost control strategies. Noting that further reductions in air pollution will be more costly, the authors focus on ways to determine the point at which costs will exceed benefits and propose a methodology for evaluating air-quality legislation. They argue that a cost/benefit approach is essential for improved decision making. The presence of interactions and nonlinearities suggested by the data indicates that uniform pollution-control standards are inappropriate. 15 references, 6 figures, 19 tables.

Analyses, experimental studies, and evaluations of control measures for air flow and air quality on and near highways. Volume I: experimental studies, analyses, and model development. Final report 1973-80

Abstract: Experimental and theoretical investigations have been made of meteorological and air quality conditions near a broad range of complex roadway configurations. These are described, and some new insights into the interrelationships among traffic, meteorology, and configuration are discussed. The development of a new and versatile dispersion model, called ROADMAP, is also described together with an evaluation of the model's performance relative to measured atmospheric and wind tunnel pollutant concentration data. The experimental data indicates a significant effect of waste heat on near-roadway dispersion. The combined effects of traffic movement and waste heat emissions cause increases in the turbulence intensity of up to 200% across the roadway. However, there is apparently little effect on turbulence caused by changes in traffic volume or speed (for the moderate-to-heavy traffic conditions present during the tests). An aerodynamic or shelter effect is postulated to exist and to be a significant influence for grade-level roads.

Ambient Ozone Concentration Patterns among Eastern U.S. Urban Areas Using Factor Analysis

Abstract: Data on maximum daily ozone concentrations measured at ambient air monitoring stations in the Eastern U.S. are analyzed using principal factor analysis. Principal factor analysis is described. The O/sub 3/ variations among stations within defined geographical areas are similar. Trends analysis for determining general progress in improving O/sub 3/ air quality should be based on aggregate statistics from clusters of monitors. (1 diagram, 4 maps, 9 references, 3 tables)