Emissions and air quality trends in the South Coast Air Basin

This paper documents the historical trends of pollutant emissions and ambient air quality for the South Coast Air Basin (SCAB) for the period 1965-1974. Emission trends for nitrogen oxides. reactive hydrocarbons, and carbon monoxide are developed. A detailed appendix describes the methodology and presents the latest test information -- in particular the contribution of evaporative emissions from light-duty vehicles. Basin-wide and county trends are presented to characterize the overall changes as well as the spatial distribution of emissions. Ambient concentrations of total nitrogen oxides (NO_x), nitrogen dioxide (NO_2), oxidant (OX), and carbon monoxide (CO) are compared to the emissions changes during the same period. Detailed analyses of air quality indices, including extreme levels, average values. and frequency of standard violation are presented for each pollutant. The final section of the paper discusses current and proposed control strategies and their impact on future air quality

Modelling a Historic Oil-Tank Fire Allows an Estimation of the Sensitivity of the Infrared Receptors in Pyrophilous Melanophila Beetles

Pyrophilous jewel beetles of the genus Melanophila approach forest fires and there is considerable evidence that these beetles can detect fires from great distances of more than 60 km. Because Melanophila beetles are equipped with infrared receptors and are also attracted by hot surfaces it can be concluded that these infrared receptors are used for fire detection

Statistical relationship between median visibility and conditions of worst-case manmade impact on visibility

A study was conducted of the statistical relationships between median visibility and the levels of visibility associated with worst-case manmade impacts. The data base for the study consisted of midday visibility recordings for the years 1974-1976 at 28 suburban/nonurban airports throughout the United States. The visibility recordings were converted to estimates of extinction coefficients with the use of the Koschmeider formula. The data were sorted according to meteorology in order to eliminate days that were obviously dominated by natural causes of poor visibility. Three approaches were used for relating worst-case (90th through 99th percentile) extinction to median extinction. The first approach was based upon frequency distribution functions. The second used observed ratios of upper percentile to median extinction. The third employed regression techniques. All of the relationships were formulated and evaluated with the 1974-1976 data on a national/annual basis as well as regional/quarterly basis. Performance tests were also run against 1954-1956 data at 11 of the 28 sites. Simple ratio relationships are recommended for use in translating median visibility impacts into worst-case impacts. The errors associated with these ratio models are approximately 30%, which is less than the error typically associated with mathematical dispersion models