In paragraph 7, it is proposed to refer to the need for isokinetic collection of particles. 1982 reduced to the level of the beginning of the 1940s, and the amount of emitted smoke has decreased by more than 80 percent in the last 20 years. This means that SO and SO can be beneficial to plants in areas where soils are deficient in sulfur.
This works best with liquid kombus. However, the process has not yet been developed for industrial use. In summary, an attempt was made to sort out the mechanisms responsible for the regional modulation of large-scale flow patterns in order to be relevant to air pollution problems in the Australian region. a). The Latrobe Vally field studies mentioned in the discussion by Peter Manins who will look at regional modulation of synoptic-scale flow are an example of the traditional approach.
Topics for Investigation 4. Suggestions for Effective
There are problems with the Bureau's database in that most of the data is irrelevant to air quality studies. Similar to radiosonde data, validated significant levels would be more useful in air quality studies than standard levels. As identified by Peter Manins, the main modifying mechanism would appear to be the land/sea breeze.
At least on a regional scale, this would be a major component of pollution episodes in the major population centers of Australia, almost all of which are located in coastal areas. ultimately depend on the latter, which is particularly difficult given the wide range of spatial and temporal scales involved, so progress is likely to be slow. Some aspects of convection that must be considered in contaminant dispersion are:. What is the mechanism through which free convection generates large-scale intermittent motions in the atmosphere.
What are the characteristics (time and length scales) of intermittent convective movements in the atmosphere. These are likely responsible for extreme events that may exceed limits set by regulatory authorities. IV). Much of the work in convection requires detailed and careful experimentation, both at prototype scale in the real atmosphere and with a simulation model in the laboratory.
But the distinction between dry convection and moist convective pro-. cesses of the real world must not be overlooked. e) Analytical and numerical models The fact that little discussion took place about the status of models of mesoscale phenomena in Australia is significant in itself. Ultimately, however, reliable predictive models incorporating such effects will be needed, and steady progress on this aspect must be continued alongside the empirical models, ad hoc experiments and technical solutions required in the short term.
A PRELIMINARY STUDY OF RAINWATER ACIDITY AROUND NEWCASTLE, N.S.W
Distribution patterns derived from combining the collected data over the entire period showed that the frequency of acid precipitation is lower for the coastal areas than in urban and residential areas. Minmi appeared to be a transitional site, while in Shortland, Beresfield and Lochinvar a high proportion of the rainfall was clearly acidified, i.e. as much of the rain falling on coastal areas had pH values in the 5.0 to 5.6 range, it could be argued that pH>5.0 provides a better cut-off point for identifying rainfall that is reasonably unaffected by pollution from Newcastle and the surrounding area.
Three main synoptic situations were found to be associated with the occurrence of the observed rain events (Table 2). Precipitation occurred primarily from either the passage of a cold front or onshore winds from a high pressure system. The Newcastle results may support this idea, as almost half (i.e. 43 percent) of the precipitation events originating from onshore winds from a high pressure system were followed by precipitation from cold fronts in a sequence of high pressure system - cold front - high pressure system - cold front, rain.
Under the influence of a high pressure system centered near New Zealand, a period of calm preceded the passage of a cold front on 23 Feb 82. Convective showers associated with the passage of a cold front may have resulted in significant pumping of pollutants below the clouds that accumulated over Newcastle during the previous days of calm conditions and very light winds. Throughout the period, the entire area was under the constant influence of the same high pressure system offshore.
Onshore winds brought a late-night thunderstorm associated with the rear of the departing high pressure system, bringing strong acid to light acid rain to the area. Although apparently under the same synoptic and wind regimes as the previous day, none of the samples collected were even slightly acidic. First, coastal sites (including Salt Ash, Hamilton South and Millers Forest) in which 47 percent of the rainfall had a pH < 5.6; and secondly, non-coastal sites (Lochinvar, Minmi, Beresfield and Shortland sites) in which more than 80 percent of the rainfall samples had a pH of less than 5.6.
Greg Ayers from CSIRO gave us a fascinating insight into the physical and chemical complexities of the formation and deposition of acidity from the atmosphere.
EIGHTH INTERNATIONAL CLEAN AIR CONFERENCE MEASUREMENT WORKSHOP
Specific chromatographic problems were diagnosed with the emphasis placed on e r o r s generated by variations of the tail edge of the NMHC peak that were significant especially when low levels of h y d b o c m e a s u r i n g low levels of h y d b o c. The calibration of the instrument is also covered with particular attention to the non-linear relationship of the F.I.D. However, it was noted that this factor was questionable and for some instruments a figure of 2.5 could apply.
It was determined that all users use the same basis for their calibrations (ie x 3) although the final results were determined by different methods. The use of alternative instruments was discussed, but it was generally agreed that the Byron NM 301 was the only instrument that was suitable. It was noted that the Byron Model 401 is now available, which converts non-methane hydrocarbons to CO and then reduces to CH4.
It was noted that some sampling and analytical techniques used in source monitoring were similar to those used in Occupational Health. It was considered that a set of guidelines for source monitoring would be an appropriate starting point. Extractive sampling techniques (including isokinetic sampling) and laboratory analysis of sample collected by accepted published methods.
Various government organizations in Australia have adopted or are in the process of formulating standard procedures covering some of the above aspects. In addition, the NSW Branch of the Clean Air Society has developed a training course and handbook on air pollution measurement that includes source monitoring techniques.
Peter W. Stephenson
A study was made of the spatial and temporal characteristics of dust and heavy metal fallout in the Hobart area. The fallout pattern was shown to be a function of wind direction and the distance of the sampling site from the source. The main source of the fallout was identified as the stockpiles of the Electrolytic Zinc Company's metallurgical works at Risdon.
Some pioneering studies were done in Hobart on dust and heavy metal pollutants of the atmosphere (3-12). The method showed how dust and heavy metal fallout (hereafter referred to by the general term 'pollution', unless otherwise stated) varied over time along a transect of the Derwent Valley. The significance of the long-term trends at the a = 0.01 level was also determined as discussed in (14).
The locations of the different sampling sites along the baseline are indicated with numbers. It was found that the natural logarithm of distance to the Risdon plant accounted for 71 percent of the total variance in zinc precipitation. This was not found in the analysis of zinc precipitation levels in the current study, as minimum temperature explained only 3 percent of the total variance when the urban average was used.
This would not happen to the same extent with winds from the N-WNW sector, as the pollutants would tend to be blown downstream and out of the airshed. Zinc sulphide is a major component of many of the stockpiles at the Risdon plant (Spencer, pers. comm.). The second component, which accounts for 14 percent of the total variance, shows high loadings for total dust, nickel, and chromium.
The statistical techniques confirm a decrease in precipitation rates for most pollutants over the four-year period.
PERSONAL
The analysis involved the use of a number of techniques and provided useful information on air quality and helped to locate sources of pollution. Summer maxima were achieved for all pollutants except cobalt and nickel. The pattern of precipitation was found to be significantly correlated with wind direction and distance between sampling sites from the sources.
I would like to thank the Department of the Environment and Bureau of Meteorology for providing the air quality data.
SAA NEWS
OVERSEAS NEWS
University of Melbourne Environmental Engineering P r o s p e c t i v e c and d i d a t e s for the multidisciplinary master's degree course in Environmental Engineering a r e informed that applications for this course close on 25 January 1985. Prospective candidates are advised that the Faculty has proposed this course, which is biennial for this course. Applications are invited for the position of editor for the Proceedings of the 7th World Clean Air Congress, to be held in Sydney on 25-29 August, 1986.
Remind accepted authors of the official deadline and ask for an explanation of any delay. The editor will also participate in the design of the notebooks and the selection of the printer. Please apply to the Secretary by February 28, 1985, including current resume and other pertinent information.
ENVIROLOGGER THE LATEST AND MOST ADVANCED DATA ACQUISITION SYSTEM
