VOLUME 17 No. 2 MAY, 1983
BRANCH PRESIDENTS ACT: Dr. N. J. Daly
NSW: J. D. Court NZ: J. Hickman
Qld: J. S. McFarlane SA: E. F. Symons
Vic/Tas: Dr. J. B. Robinson WA: D. G. Saunders
BRANCH CORRESPONDENTS ACT:
NSW: Steve Stanley NZ: Ron Pilgrim
Qld:
SA:
Vic/Tas: Jack Chlodo WA: D. B. Sykes
The opinions expressed by authors and contributors are their own and do not necessarily represent the view of the Society.
EDITOR
Dr. R. G. Gillis,
75 Downshire Rd., Elsternvvick, Victoria 3185, Australia.
Phone: (03) 528 2507.
ASSOCIATE EDITOR Sylvia J. Mainvvaring
EDITORIAL BOARD R. G. Gillis
H. F. Hartmann
Sylvia J. Mainvvaring J. 0'Heare
ADVERT1SING
Enquiries should be directed to Miss Ann Sykes,
C/- Appita,
191 Royal Parade, Parkville, Victoria 3052.
Phone: (03) 347 2377.
PRINTER
Advocate Press Pty Ltd (03) 329 6588
Vol. 17, No. 2, May 1983
JOURNAL OF
THE CLEAN AIR SOCIETY OF
AUSTRALIA AND NEW ZEALAND President: K. M. Sullivan
Secretary: R. W. Manuell Treasurer: Dr. K. S. Basden
Postal Address:
Box 191, Eastvvood, N.S.W. 2122.
EDITORIAL
J. S. McFarlane 22 TECHNICAL PAPERS
An Initial Assessment of
Pollution Dispersion by Sea Breezes in the Latrobe Valley
W. L. Physick 24 Nocturnal Air Circulation in the Latrobe Valley
P. C. Manins 29 FEATURES
Announcements 28, 32
Book Reviews 28
Branch News 23 Conferences and Courses 23
Overseas News 23
EDITORIAL
Air pollution control authorities find that most complaints from the public are about the very local issues of dust, smoke, or odours from a neighbour's property. The reaction to these complaints is often to despair of the lack of planning that resulted in these incompatible neighbours.
The Australian suburban ideal appears to have presented challenges to planners t h a t defy the best i n t e n t i o n s . S u b u r b a n h o m e developments have spread out like a wave front a r o u n d our cities competing for space, roads, water and air with factories that were formerly considered to be well sited. This has resulted in an uneasy truce between factories, perhaps many kilometres from a c i t y c e n t r e , and t h e surrounding housing. The opposing forces are on one hand, the need of the factory for services, its proximity to its sources of raw materials and its markets, and ultimately the costs of its relocation, and on the other hand, the home owner's equity in his home and the vulnerability of this to the smoke and odours experienced there.
One thing he has going for him is, of course, that he did not notice the factory when he bought his property and potential buyers may not notice it either.
One result of this to the industry concerned is the use of air pollution control equipment usually of the best technology affordable. The pages of this Journal and the Proceedings of the Society's Conferences are packed with details of such technology. Yet despite this, in a great many cases the
reputation of an industry is sullied by frequent "one-off" emissions of particulates or odours in the plant.
It is almost certain that daily throughout A u s t r a l i a and New Zealand, Inspectors of control
authorities are investigating emission incidents and trying to determine the causes. Equally certain is that the offensive smoke or odour is not there during their visit to the offending f a c t o r y . O f t e n t h e i n d u s t r i e s concerned have spent considerable
22
funds on control equipment and have the best of intentions towards their neighbours. They may despair of the ' P o o r town planning'1 of their neighbourhood that they may believe to be responsible for their problems.
But the fact remains that they are in trouble when they do not want to be.
In other words, some of the objectives of the organization are not being accomplished and the real reason for the problem may very well not be poor town planning but what is best described as unsound management in
their own organization.
Experience is showing us that, for an industrial plant, the elimination of spurious small scale air pollution events can only be accomplished when
this is c l e a r l y defined as a management objective, accountability
for the achievement of this objective is clearly spelt out at all levels of the organization, and when this objective is given equal priority with other major objectives of the organization.
This, no doubt, reminds us of the
"Management by Objectives"
programs that have undergone considerable development in the last
fifteen years. Certainly "Air Pollution Control by Objectives" is a proven way to deal with problem emissions.
The concept is simple — a manager and his team work together in identifying realistic objectives and plan ways to achieve them. Objective
setting normally starts from top management and the objectives of every level of management become interlinked until the first line supervisors become committed to the objectives. In the process of working
out goals with their people most managers discover problem areas they would not have otherwise been aware of. But the essence of good Management by Objectives and good Air Pollution Control by Objectives is t h e r o u t i n e c o n t r o l l o o p o f measurement of progress towards the objectives and feedback so that corrective action is taken such as g u i d a n c e , r e i n f o r c e m e n t o r modification of the time scale for the objective.
Further management systems are available for adaption to this area of management of air pollution. In the last ten years control of the increasing size of hazards in the chemical industry has given birth to the concepts of Loss Prevention and Total Loss Control. In organizations applying these systems an air pollution event is regarded as a "loss".
Other types of losses are injuries to people, plant breakdowns, material
losses, equipment damages, and defective product quality. These
systems are based on the belief that control of these losses can only be a c h i e v e d t h r o u g h e f f e c t i v e
management and that failures are the result of faults in the management system. The key to loss prevention systems is the development of an effective method of analysing the underlying causes of incidents. For example, an air pollution event would be analysed to discover why the underlying cause was permitted to exist. The level of operator training, the standard of maintenance, the
attitudes and training of supervisors, and management policies would all be examined. The reporting of potential incidents is encouraged and these are similarly analysed.
The application of these systems to air pollution control is now happening and will m a k e a s i g n i f i c a n t contribution to the reduction of pollution incidents. In General it is being accomplished by extending the role of safety support staff so that their function includes pollution control. They then act as guardians of the company's pollution performance as well as its safety performance.
As this development occurs it is bringing a new group, namely safety professionals, into the area of air pollution control. I look forward to the sharing of experiences in this area, in particular to the presentation of papers on "Air Pollution Control by Objectives" and " A i r Pollution Control by Loss Prevention" at Conference of the Society.
Not the least valuable part of such papers would be advice on how to gain acceptance within an organization for improved systems of pollution management. With so many members of the society involved in the prevention of air pollution incidents and well aware of the management effort and planning required, and with the new management systems being tried in this area, I can assure potential authors of considerable interest in their papers.
J. S. McFARLANE Deputy President President — Queensland Branch
Clean Air/May, 1983
BRANCH NEWS
New South Wales
The Annual Meeting of the New South Wales Branch of the Society was held on 8 February, 1983. The Office-bearers of the previous year were re-elected and are as follows:
President: J. Court, Imm. Past President: K. Sullivan, Secretary: S.
Stanley, Treasurer: N. Lamb, Committee: K. Basden, R. Bilger, A.
Crapp, R. Manuell, G. Johnson, B.
Smith, J. McLeod.
The air pollution which afflicts Sydney from May to October is generally referred to as "Brown
Haze". Mr. David Williams of the Atmospheric Chemistry Section of the
Mineral Research Laboratories, C.S.I.R.O., has for some years headed
a research project studying this phenomenon. Motor traffic and
incineration have been identified as major contributors. At the meeting his subject was "The Nature and Origin of Sydney's Atmospheric Aerosol", which was well received and generated
lively discussion.
Victoria — Tasmania
At the last Annual General Meeting of the Branch, the following committee was elected for 1983/84.
President: Dr. J. B. Robinson, Past President: Mr. J. 0'Heare. Secre- tary/Treasurer: Mr. W. R. Hicks.
Committee Members: J. Chiodo, R.
Farhall, Dr. R. Gillis, H. Hartmann, J. Lysenko, S. Mainwaring, G. Seager, C. Smit, F. Smith, Dr. J. J. Todd and P. Williams. Council Representatives:
Dr. J. B. Robinson and Mr. H.
Hartmann.
Mr. Hartmann is also the Organiz- ing Secretary for the 1984 Clean Air Conference to be held in Melbourne on 6-11 May 1984. Selection of papers for presentation at this conference has now been completed and authors will be advised shortly. Because of the large number of papers offered, it has not been possible to include all papers for presentation. However, authors of papers which cannot be fitted into the formal presentation will be offered the opportunity to both present a poster and to have the paper published in the proceedings.
During March Dr. J. Mathews, Head of the ACTU Trades Hall Coun- cil Health and Safety Unit addressed a lunch tirne meeting on the subject of the Australian Labor Party's initiatives in the control of chemicals in industry.
Dr. Mathews outlined the proposals for a National Register and licensing system for new chemicals and how these might be implemented, with par- ticular reference to Victoria.
Clean Air / May, 1983
The Victorian Government has recently appointed Mr. J. Wright as Chairman of the EPA. Mr. Wright will be invited to address a lunch tirne meeting of the society at an early date.
OVERSEAS NEWS
Michael Foot becomes NSCA Vice-President
The Rt. Hon. Michael Foot, MP, was elected Vice-President of the National Society for Clean Air at the Society's AGM held in Llandudno on 18 October, 1982. Mr. Foot had previously agreed to the nomination, which was made by Cllr. J. R. P.
Evans of the NSCAs South and Mid Wales Division. Mr. Bernard Twyford expressed the Society's pleasure at Mr. Foot's acceptance of the honorary office (which is held for a period of three years) and said that his support would be invaluable.
From Clean Air (UK) 12, 106 (1982).
CONFERENCES AND COURSES
The D e p a r t m e n t of Chemical Engineering at the University of Queensland and the School of Civil Engineering at the University of New South Wales are jointly sponsoring two intensive continuing education courses in the field of water and wastewater treatment. Both courses will be held at the Boulevarde Hotel, William Street, Sydney. Details are as follows: "Principles of Wastewater Treatment Design and Operation" — July 18-22, 1983. "Management of Hazardous, Toxic and Intractable Wastes" — July 18-22, 1983.
The principal lecturers for these courses will be Professor Wes
Eckenfelder from U S A, Dr Peter Coakley from UK, Professor Steve
Hrudey from Canada, Dr David Barnes from UNSW and Dr Paul Greenfield from University of Queensland.
Further details may be obtained from either of: Dr. P. Greenfield, Department of Chemical Engineering, University of Queensland, St. Lucia, Q 4067, or Dr D. Barnes, School of Civil Engineering, University of New South Wales, PO Box 1, Kensington, NSW, 2033.
An lnterdisciplinary Centre for Research on the Environment:
Institute for Environmental Studies of the University of Toronto
The Institute for Environmental Studies is an interdisciplinary centre for research and study which offers association with a wide range of social and natural scientists. The primary goal of the Institute is to provide the facilities and
academic climate for problem-oriented research to those who wish to maintain their discipline- based academic work. M.A./M.Sc. programs are therefore undertaken on a collaborative basis with one or more core departments;
research programs usually involve at least one core discipline. The core disciplines which currently offcr collaborative M.A./M.Sc.
programs with the Institute are the departments of GeoIogy, Botany, Forestry, Zoology, Geography, Anthropology.
Collaborative M.A./M.Sc. Program: Each študent in the Collaborative M.A./M.Sc.
Program in Environmental Studies undertakes a research project leading to a thesis or research
paper in his/her basic discipline. Students also lave the opportunity to intern with a government agency, a consulting firm or a public interest group.
The internship provides students with 4-8 months of "real world" work experience in some environmental field related to their program of studies and research.
For each of the collaborative programs, the Institute offers required c o u r s e s in environmental management and man- environment theory and over 15 electives in applied ecology, economics, environmental economics, environmental law, technology, environmental microbiology, interdisciplinary toxicology, water resources management, population and resources, mathematical ecology and socio-ecology.
Research Activities: A large and varied group of individuals is associated with the Institute for research purposes. Many opportunities exisl for both formal collaboration and informal discussion including laboratory and field studies, weekly seminars and hot seats, svmposia, workshops and working groups.
Working Groups: The Institute Working and Study Groups have proven to be a very successful means of organizing people from diverse disciplines and departments around a problem of common interest. Formed either to resolve specific problems or to study fields of current interest, they often receive funding, produce reports and publications and provide resources for the university and surrounding and rural communities.
Currently active groups are involved in:
Arctic Studies; Chemical Analysis; Climate and Human Responses; Computer Aided Planning;
Ecosystem Breakdown; Energy Studies;
Environmental Monitoring; Environmental Perception and Policy; G r e a t L a k e s Rehabilitation; Oil and Gas; Persistent Substances; Risk Assessment; Snow and Ice Control; Solid Waste Studies; Technology, Environment and Development; Urban Natural Systems; Water Resources Management.
Other fields of research at the Institute are environmental conservation, social impact assessment, public participation and socio- ecology.
The Institute for Environmental Studies also offers the use of an excellent Iibrary, specialized laboratory facilities for ecotoxicology, the Slowpoke Nuclear Reactor and Baie du Dore field station on Lake Huron.
For further information and/or application, please write to:
Prof. A. P. Grima, Coordinator of Graduate Studies,
Institute for Environmental Studies, Haultain Building, 170 College Street, University of Toronto,
Toronto, Canada M5S 1A4.
Extracted from SCOPE Newsletter No. 16.
23
Dr. Bill Physick is with the CSIRO Division of Atmospheric Physics, P.O. Box 77, Mordialloc, 3195. He i s a l s o C o n v e n o r o f t h e International Conference on Mesoscale Meteorology to be held at the University of Melbourne in February 1984.
ABSTRACT. The role of the sea breeze in the dispersion of pollutants has been studied in a number of localities. In this paper, the surface
climatologv of the Latrobe Valley sea breeze is combined with aspects of
those studies to identify areas in the Valley which are likely to be affected most by sea-breeze dispersion. With the current distribution of emitters, it appears the arrival of the sea breeze may improve the air quality in all regions, although on occasions it may transport emissions to the upper part of the Valley beyond Yallourn. Details of a possible field study to further examine the ideas of this paper are presented.
INTRODUCTION. During the warmer months of the year, on days when air over land is heated to a significantly higher temperature than air over the sea, a horizontal pressure gradient is set up across coastlines and low level air flows from sea to land. A compensating return fiow develops above and the resulting circulation expands horizontally and vertically throughout the day before diminishing in the late afternoon, eventually dying out in the early evening. Clarke (1) has tracked sea breezes as far inland
as Kalgoorlie (300 km) where they have arrived about midnight, but penetration this far inland is not a comrnon occurrence. The inflow depth can be anywhere between 200 m and
1000 m, depending on location and synoptic wind. The layer of return flow above is usually twice the depth of the inflow.
The sea breeze represents an influx of relatively clean maritime air and thus provides an ideal flushing mechanism for a contained area such as a valley. However, the cooler air undercutting the warmer land air may produce adverse effects such as reduced mixing depths and fumigation associated with the thermal internal boundary layer. Recirculation of pollutants in the sea breeze circulation can also be a problem in some regions and has been documented by Lyons and Olsson (2) in association with the Chicago lake breeze.
Latrobe Valley sea breezes have been investigated by Tapp and Hoy (3), and by Physick (4), with the latter finding that sea breezes from the east coast regularly penetrate up the Valley as far as Hazelwood (85 km) in the summer months. However, both these studies have analysed surface data only, and have not attempted to link
anomalous pollutant concentrations with sea breezes. In the next section of this paper, a summary of findings from those studies is presented.
Following that, results of sea breeze and pollution studies in other localities are adapted to the Latrobe Valley in order to identify those areas which could be affected most by sea-breeze dispersion of pollutants. The final
s e c t i o n o u t l i n e s w h i c h f i e l d observations should be made to estimate better the impact of the sea breeze on the air quality of the region.
SEA BREEZE CLIMATOLOGY. In their study of surface wind fields in the Latrobe Valley, Tapp and Hoy (3) identified two different sea breeze regimes. One originates at the coastline east of Šale and regularly pentrates as far as Hazehvood (see Figure 1). On occasions, it can be detected further west at Yarragon North. The second sea breeze comes over the Strzelecki Range at the saddle near Boolarra and travels down the Morwell River Valley to reach Hazelwood from the southwest. This sea breeze originates at the south coast near Wonthaggi and occurs less frequently than that from the east coast, probably because of the topographic barrier some 200 m high which it must cross to enter the Valley. However, both sea breezes can
occur at the same Iocation on the same day, usually meeting somewhere
between Hazelwood and Traralgon. It appears the east coast sea breeze is stronger and it continues on to the Hazelwood area. The sea breeze from the south coast can also enter the Valley near Warragul, originating in the Westernport Bay area. There is evidence of it progressing on to Yarragon North, but it is unlikely to reach Yallourn. Tapp and Hoy reached their conclusions from an analysis of wind roses and frequency of winds from certain directions as a function of tirne of day. It was a preliminary study and as such fulfilled its objective "to identify any local wind circulations in the Valley, together with their approximate horizontal extent".
24 Clean Air / May, 1983
OF POLLUTANT DISPERSION BY SEA BREEZES
IN THE LATROBE VALLEY
William L. Physick
A more detailed investigation of the sea breeze systems in the Valley was c a r r i e d o u t by P h y s i c k (4).
Windspreed and direction traces from Woefle anemometers at Giffard,
Rosedale and Hazelwood were examined for two summers. Wind data from Yarragon North were also available for one of the summers.
These stations are marked on Figure 1 and were chosen for analysis because of their location with respect to the arrrival tirne of the more frequent sea breeze from the east coast viz.
morning, afternoon, late afternoon and evening.
For each day of the study period, the Giffard wind record was examined
for mid-morning light onshore winds strengthening later and persisting through the day. For these days, the synoptic situation was checked for relatively light gradient winds with little direction change during the day.
Days which satisfied these criteria were deemed sea-breeze days. A total of 54 such days were found in the 12 analysed months, and various statistics for each station are shown in Table 1. The number of sea breezes is denoted by n, the mean arrival tirne by t, and m e a n d i r e c t i o n by 6.
Unfortunately, data at Rosedale were available for only three of the seven sea-breeze days in October. In the statistics for Yarragon North, an expression such as '3 of 4' means the sea breeze reached there on three of the four days on which there was a sea breeze at Rosedale.
The two preferred arrival directions at Rosedale indicate two different paths, with the mean arrival tirne encompassing the sea breezes from
both directions. When the sea breeze arrives from the northeast, it has come up the Valley, i.e. around the
northeastern end of the Strzelecki Range. However, the arrival direction of east-southeast indicates that the sea breeze has travelled over the hills from the coastline in the vicinity of Giffard.
The synoptic situation determines which path is chosen, the latter direction being preferred on 3 out of 4 occasions. A discussion of the statistics of Table 1 with respect to tirne of year, synoptic situation and topography can be found in Physick (4). Further reference to this Table is made in the following section where the role of the sea breeze in pollutant dispersion is discussed.
Wind records from April to September were not examined, but the wind roses of Tapp and Hoy (3) for these months show pronounced afternoon easterly winds at Giffard and East Šale. However this does not occur to the same extent at stations
further inland, suggesting that sea breezes in the cooler months are confined to the coastal zone.
Figure 1. Latrobe Vallev region of southeast Australia. X indicates an anemometer site.
P O L L U T A N T D I S P E R S I O N . Typically a sea-breeze day is sunny with light winds. On such a day, the mixed Tayer of the atmosphere is deep
and consequently the ground-level concentration of pollutants is relatively low. Jones (5) defines the depth of the mixed layer as "the height of the atmosphere above ground level below which vigorous mixing occurs due to either mechanical or convective turbulence." The acoustic sounder records of Jones in the Latrobe Valley show that this layer can extend to a height of about 1400 m in the summer.
They also show that the depth begins to decrease rapidly at about 1700 hours, finally reaching by 1900 hours
a fairly constant nocturnal value between 50 and 100 m. This sharp decrease indicates a decline in convection and the formation of a growing stable layer near the ground.
Coincidentally, the mean arrival tirne of the sea breeze at Hazelwood is
also about 1700 hours. Currently, power stations and industry in the Yallourn-Morwell-Hazelwood area produce the major part of emissions in
the Valley, and thus the ratio of plume rise height to sea breeze depth is quite important. Clearly if the plume rise exceeds the height of the inflow layer, the emissions will be advected down
the Valley in the sea-breeze return flow (Figure 2a). It is most unlikely any of this plume will descend through the inflow layer to the ground (2). If plume rise height is less than the depth of the sea breeze, the plume will be advected inland but isolated from the ground by the stable layer which
develops beneath it during the late afternoon (Figure 2b). Thus it appears the c u r r e n t e m i t t e r s may be fortuitiously located as far as dispersion by the sea breeze is concerned.
A further aspect to be considered is the dynamical change in the sea breeze circulation as it encounters a stable lower a t m o s p h e r e in t h e l a t e afternoon. Numerical studies (Physick (6)) and observations (Simpson et al.
(7), Clarke (8)) show that this tirne a cut-off vortex betvveen 7 and 30 km in horizontal extent can develop at the leading edge of the circulation and propagate inland at a faster rate than the daytime sea breeze. It is not known whether this occurs in the Latrobe Valley, but if so, it is a mechanism for c o n c e n t r a t i n g emissions in a limited area and bringing them to ground level in the descending arm of the vortex. Figure 3
schematically shows the transport of pollutants within such a vortex. The author has tracked sea breezes beyond Yallourn into the upper Latrobe Valley and Moriarty (9) attributes a markedly high hourly NOx reading at Darnum North (about half-way between Yarragon and Warragul) to the onset of a sea breeze.
The studies of Tapp and Hoy (3) and Physick (4) found an afternoon peak in the frequency of south- westerly winds at Hazelwood, prior to the arrival of the east coast sea breeze.
The latter study found that under certain but infrequent synoptic conditions, the south-westerlies constituted a sea breeze from the
south coast. In the San Fernando Valley, California, Edinger and
Helvey (10) i n v e s t i g a t e d t h e convergence zone created by sea breezes from opposing directions. This zone consisted of a windshift line up to
a h e i g h t of 700 m a n d was compensated by divergence above through a layer of comparable thickness. Air pollution arriving from the east was pumped aloft in this zone and distributed according to the upper
Clean Air/May, 1983 25
1. Mean arrival time and direction of the sea breeze at various locations. Note that the sample size n denotes everywhere the total number of sea breezes observed in two years.
vvinds. In the process of completelv changing its direction of flow, the air in the vveaker sea breeze from the east apparently piles up in the convergence zone forming an obstacle over which the westerlies first ascend then descend. Application of these findings to the Latrobe Valley means that a convergence zone, initially forming betvveen Traralgon and Morwell and moving westwards towards Morvvell, would quite likely return pollution to the Hazelwood region after it had been temporarily advected eastvvards by the south-westerlies. An air quality monitor situated in this area vvould register a rise in concentration as the south-westerlies set in, then a further
rise when the wind decreases and backs in the convergence zone and finally a fall as the relatively clean air from the east coast arrives.
In a study of the effects of m e t e o r o l o g y o n t h e o z o n e
concentration in the Sydney area (Hyde et al. (77) found that ozone readings increased abruptly with the onset of the sea breeze. This occurred even at coastline stations and was due to oxidant precursors, transported offshore by westerly drainage flow during the morning, being advected back onshore by the sea breeze. A similar phenomenon occurs in Melbourne with the Port Phillip Bay breeze (Evans et al. (72), but in this case the onshore breeze tranports the major pollutant parcel clear of the metropolitan area and distributes it over the rural region to the north and west of Melbourne. As far as the
Figure 2. Schematic diagram of emission dispersion by the sea breeze when (a) plume rise height is greater than sea-breeze depth, and (b) plume rise height is less than sea-breeze depth. This is the late afternoon čase vvhen a stable laver has developed near the ground.
Latrobe Valley is concerned, the data analyses of Tapp and Hoy (3) and Moriarty (9) found no clear evidence of any coherent drainage along the
axis of the Valley from west to east.
This fact, combined vvith the relatively large distance inland of the major emitters, makes it unlikely that the sea breeze will bring in pollutants
transported offshore in the early morning. This aspect vvould of course need re-evaluation if future emitters are to be located much nearer the coastline, where land breezes could be expected to play a role.
Any assessment of the role of the sea breeze in pollutant dispersion in the Valley must take into account not only the current distribution of pollution sources but also any future distribution. If emitters are to be sited
further tovvards the coast than at present, than their interaction with sea breezes would be quite different. From
an examination of pilot balloon data at East Sale, Tapp and Hoy (3) estimate the top of the sea breeze inflow layer to be typically about 500 m, with few if any extending to 1000 m. This is well above any proposed power station stack heights (e.g. 260 m for Loy Yang) and thus emissions would be into the incoming sea air.
When allowance is made for a plume rise of 1 to 3 times the stack height, there may also be occasions when the plume reaches the sea breeze return
flow layer.
Although the incoming sea air is stable as it crosses the coast, it is subject to heating as it moves inland
26 Clean Air/May, 1983
Giffard Rosedale Hazelwood Yarragon North
n t 6 n t d n t B n t
October 7 0940 ESE 1425 6 1725 ENE Nodata l
1 NE 2 ESE
November 5 0930 E 1450 5 1710 ENE Nodata 3 ENE
4 ESE
December 7 0925 ESE 1415 7 1635 ENE 0 of 2 — 3 ENE
OcL. Nov., Dec. 19 0930 15 1430 18 1700 — — 6 ESE
January 8 1050 SE 1525 7 1740 ENE 3 of 4 1910 2 NE
15jz ESE
February 17 1010 SE 1525 11 1735 ENE 3of3 1930 2 ENE
9 ESE
March 10 1045 SSE 1500 6 1745 ENE 0of7 — 1 NE
Jan., Feb.,Mar. 35 1030 35 1520 24 1740 6 1920
and an internal thermal boundary layer (ITBL) develops. Emissions into the sea breeze near the coast may initially be advected inland at the level at which they are released, but quite likely the deveioping ITBL will eventually reach this height and
fumigation will occur, bringing pollutants to ground level.
For near-coastal emitters, further problems can occur with recirculation.
In a study of air pollution dispersion in the Chicago lake breeze, Lyons and Olsson (2) found that constant level balloons released at the coastline
recirculated vvithin the lake breeze celi, describing a helical trajectory
roughly centred on the coastline. This finding, together with cross-sections of particulate concentration obtained
from an instrumented aircraft, strongly suggested that a significant
fraction of the pollutants released from nearshore sources moved inland within the inflow, rose aloft at the
front, advected lakeward in the return flow layer, and then sank back down into the inflow layer offshore before
returning over the land again, causing ever increasing pollutant loading of the atmosphere. The percentage of particulates returned depended on the particle size as it was found larger particles (7-9 μm) with significant terminal velocities tended to fall out over the lake and thus were not
recirculated.
In this Chicago study, a balloon released at the coastline at 0900 CST travelled 4 km inland before rising at the front and returning to descend over the lake about 1.5 km offshore. It crossed the coastline again about 2 hours after release, covering a total distance of 11 km in this tirne. These figures indicate there would be no problem with recirculation in the Latrobe Valley with the current distribution of emitters, about 85 km
inland near Hazelvvood. Even if pollution sources were to be located as
far east as Sale (25 km inland) where the sea breeze arrives at about 1330 EST, it is extremely unlikely any emissions could be returned before the circulation in that area decayed at nightfall. Hovvever, the previously
mentioned fumigation process would most likely be a serious problem in this region.
A FIELD STUDY. The discussion of the previous section underlines the need for a field study to investigate certain aspects of the sea breeze. In view of the quite detailed SECV netvvork already in the Valley, extra observing platforms could be kept to a minimum. For example, on selected days mini-radiosondes to obtain temperature profiles in the lovvest 1 to 2 km and frequent pilot balloon flights
from 3 or 4 sites could provide
Figure 3. A schematic diagram indicating the pollutant distribution within a cut-off vortex at the leading edge of a sea breeze. (a) Soon after arrival at an emitter and (b) at a later stage (vvithin 1 hour). Although the horizontal sea le shown is 7 km, values of up to 30 km have been observed. The streamlines of flow relative to the front correspond to a southern England sea breeze observed by Simpson et al. (7). The zero streamline (dotted) marks the boundarv of the cut-off circulation.
answers to the questions previously raised.
The problems of the dispersion of current emissions in the Morwell- Hazelwood-Yallourn area and the possible existence of a late-afternoon cut-off vortex could be investigated with data on upper winds (pibal flights or Doppler radar) at Morwell, Trafalgar (8 km east of Yarragon), Flynn and a station between Rosedale and Sale, in conjunction with mini- sonde data from the Morwell area. A study of the convergence zone between Traralgon and Morwell would require
an additional upper wind station west of Traralgon. The problem of the internal thermal boundary layer and fumigation only arises if emitters are located much nearer the coast than at present and is not of immediate concern. However, the deployment of acoustic sounders in this area would provide useful first information on the
ITBL depth.
SUMMARY. From October to March, sea breezes from the east coast regularly p e n e t r a t e as far as
Hazelvvood. On occasions in the summer months, they have been
observed as far west as Yarragon. The sea breeze reaches the industrialised Hazelwood region in late afternoon, just as the lower layers of the atmosphere are becoming stable.
After this tirne, emissions at higher levels are prevented from reaching the ground and the arrival of the relatively
uncontaminated sea breeze constitutes an inflow of clean air to the region. If the sea breeze penetrates past Yallourn, which seems to occur in January and February only, the emissions may be trapped in a cut-off
vortex which can develop at the leading edge of the sea breeze in the late afternoon. This vortex has been observed in other areas of Australia and is a means of bringing emissions to ground and transporting them further up the Valley towards Yarragon.
A f t e r n o o n s o u t h - w e s t e r l i e s sometimes occur in the Hazelwood region prior to the arrival of the east coast sea breeze, with a convergence zone deveioping betvveen Morvvell and Traralgon. It is under these conditions
that the industrial complex area is likely to experience the highest pollutant concentrations as emissions
Clean Air/May, 1983 27
into the south-westerlies are brought back by the sea breeze.
The current distribution of emitters well away from the coast renders the
sea-breeze problems of re-circulation and fumigation of little concern.
Hovvever, these are aspects to be considered if future emitters are to be
sited in the vicinity of the coastline.
It is felt that a field study involving mini-radiosonde flights near Morwell and pilot balloons at 3 or 4 sites could shed further light on the problems raised in this paper.
Received for review, 25 February 1983;
accepted for publication, 11 March 1983.
REFERENCES
1 Clarke, R. H. Some observations and comments on the sea breeze. A ust.
Meteorol. Mag., No. 11, 47 (1955).
2. Lyons, W. A. and Olsson, L. E. Detailed meso-meteorological studies of air pollution dispersion in the Chicago lake breeze. Man. Weather Rev., 101, 387 (1973).
3. Tapp, R. G. and Hoy, R. D. Characteristics of surface wind fields in the Latrobe Valley.
State Electricity Commission of Victoria, Report No. SO/80/18 (1980).
4. Phvsick, W. L. Sea breezes in the Latrobe Valley. Ausu Meteorol. Mag., Vol. 30, 255 (1982).
5. Jones, D. E. Drainage flows and mixing depth at Lov Yang (Minniedale Road) from acoustic sounding records. State Electricity Commission of Victoria, Report No.
SO/82/47 (1982).
6. Physick, W. L. Numerical experiments on the inland pentration of the sea breeze. Q. J.
R. Meteorol. Soc, 106, 735 (1980).
7. Simpson, J. E., Mansfield, D. A. and Milford, J. R. Inland penetration of sea- breeze fronts. O. J. R. Meteorol. Soc, 103, 47(1977).
8. CIarke, R. H. Horizontal mesoscale vortices in the atmosphere. Aust. MeteoroL Mag. No. 50, 1 (1965).
9. Moriartv, W. Air dispersion capability of the Latrobe Valley Air Shed: a brief overview. Bureau of Meteorology report to the LVASSSC(1981).
10. Edinger, J. G. and Helvev, R. A. The San Fernando Convergence Zone. Buli. Am.
MeteoroL Soc, 42, 626 (1961).
11. Hyde, R., Hawke, G. S. and Heggie, A. C.
Effects of meteorology on concentrations of ozone in Sydney. Annual Report to the State Pollution Control Commission,
N.S.W. for the period July 1976 to December 1977.
12. Evans, L. F., Weeks, I. A. and Eccleston A.
J. The source areas and impact areas of photochemical smog in Melbourne. Clean Air (Aust.), 16,45 (1982).
28
Atmospheric Sulfur Deposition. Edited by D. S. Shriner, C. R. Richmond and S. E.
Lindberg, Ann Arbor Science, available from Buttervvorths Limited, Sydney.
Polluted Rain. Edited by T. Y. Toribara, M.
W. Miller and P. E. Morrovv, Plenum Publishing Corporation N. Y. Priče:
US$49.50.
Environmental and Climatic impact of Coal Utilization. Edited by Jag J. Singh and Adarsh Deepak, Harcourt Brace Jovanovich Group, Sydney. Priče: A$50.90.
These three books are the printed conference proceedings of three related conferences held in USA in 1979. Ali three volumes have relevance to the pollution implications of increased use of coal, particularly in the production of electricity and the associated potential increased emission and transport of sulphur species.
"Atmospheric Sulfur Deposition" does by far the best job of bringing together the papers of a conference into a useful and topical book. This is mainly due to the conference having well- defined airns, and the fortitude or ability of the organizers to bring those aims to fruition. The intention was to collect together people from a wide range of disciplines, both scientists and decision makers, and to present "new research findings in the context of state of the art reviews of the subject area". The emphasis is on effects, and the areas covered are: Environmental versus Control Costs; Natural and Anthropogenic Sources; Human Health Effects; Atmospheric Trans formation; Air Mass/Landscape Interactions; Process Level Effects (intake and accumulation by plants and effects on plants);
Ecosystem Level Effects and Regional Scale Studies. Each section starts with an overview which puts the research papers in the context of existing knowledge. In addition, the research papers themselves are comprehensive rather than narrow, making the book of interest to anvone with a passing interest in sulphur deposition and offering a fairly comprehensive text as background information to those doing active research in the area.
"Polluted Rain" also deals with deposition of sulphur but specifically deposition in precipitation and not only of sulphur but of other pollutants, most importantly that other contributor to acid rain — nitrate. Most of the papers are based on the American experience and American data. However, there is an excellent survey of rainfall chemistry in The Netherlands and a Norwegian paper on the present level of cooperation among European countries aimed at monitoring and assessing the transport of acid pollutants across international boundaries. Several papers are presented on the effects of acid rain: on plants; plant growth;
soils; buildings, and fish. The effect of pH on the transformation, transport and accumulation of mercury and possibly of aluminium in fish, is covered in several papers.
"Environmental Impact of Coal Utilization"
is wider in its scope than the other two and less satisfving as a state of the art coverage. This is probably because the conference was not organized with the book in mind, making the resulting publication a collection of related papers rather than a useful text on the subject.
This limits the book's appeal to those with specific interest in the papers presented. For other readers, the book is neither an introduction to the subject nor a useful reference work. Subject areas covered in detail are:
aerosol formation, characteristics and optical effects; carbon disulphide and carbonyl sulphide, which are not related to coal combustion at ali, and potential climatic effects associated with carbon dioxide emissions.
S. J. MAINWARING
ANN0UNCEMENTS
Australia Opens its Largest Šolar Power Station
Australia's largest solar/diesel hybrid power station was opened on 9 November, 1982. The installation comprises a 50 kW array of parabolic šolar collectors and a 50 kW heat recovery system at the Meekatharra diesel power station in Western Australia. The system is linked to existing power generation equipment and is the first solar/diesel hybrid povver plant of its kina in the world.
The project has materialized after more than two years of planning and development by the State Energy Commission of Western Australia, the Government of the Federal Republic of Germany, the West German manufacturer, M.A.N., and the Šolar Energy Research Institute of Western Australia (SERIWA).
Mirrors mounted on 30 pedestals vvithin the "šolar farm" are used to concentrate the sun's rays on to specially-coated absorber tubes containing oil. The hot oil is pumped to a storage tank vvhich also receives waste heat recovered from the exhausts of the three largest diesel engines at the power station. The thermal oil is then transferred to a power conversion system. This process provides energy equivalent to 100 kilowatts (kW) of peak electric power, vvhich represents a fuel saving of about
100,000 litres of diesel oil over a year.
The project cost SA3.6 million with the State Energy Commission of Western Australia contributing approximately 46 percent, the Government of the Federal Republic of Germany 38 percent, the M.A.N.
company 13 percent, the National Energy D e v e l o p m e n t and Demonstration Council 2 percent and
SERIWA 1 percent.
SERIWA provides support for over 60 research and demonstration projects in the fields of šolar and wind energy, energy storage and the production of alternative fuels.
SERIWA is also the Congress Secretariat for the International Šolar
Energy Society,s "1983 Šolar World Congress". The Congress will take plače in Perth, 14-19 August, 1983.
The Meekatharra installation will be one of the featured technical tours available to Congress delegates.
Clean Air/May, 1983
NOCTURNAL
VALL
Peter C. Manins
Peter Manins is a Senior Research Scientist engaged in laboratory and n u m e r i c a l modelling of situations involving complex terrain and atmospheric inversions. He works for the newly reconstituted CSIRO Division of Atmospheric Research, P.O. Box 77, Mordialloc, Victoria, 3195.
ABSTRACT. Current understanding of nocturnal air flows in the Latrobe Valley of southeast Australia is presented. The discussion focuses on two aspects. The first is the behaviour of down-slope flows of cold air and the role they play in trapping pollutants in the Valley. The second, a result of blocking of the gradient wind field by the Ranges to the north and south,
involves the recirculation of pollutants in eddying motions on the scale of the
Valley.
INTRODUCTION. In addition to its dairy farming, the Latrobe Valley (LV) is important because of the large deposits of brown coal which are currently being utilized in the generation of most of Victoria's electricity. An ongoing program of monitoring and study of the air quality and meteorology of the region is directed towards a continued review
of the capability of the Valley to accept the emissions from existing and
future major sources (Hart (1)).
This paper attempts to assess our current understanding of nocturnal wind circulations in the LV from the viewpoint of air pollution problems.
As is evident from the prevalence of light winds at night at sites listed in Table 1 (from Tapp and Hoy (2)),
these conditions are of greatest interest, particularly since they are likely due to processes absent during the day. Figure 1 indicates the positions of the listed sites, at which anemometers were generally installed at two metres above ground level, and their relationship to the major
orography of the region. Note that Laverton (Table 1) is the main Bureau of Meteorology site near Melbourne.
SLOPE WINDS- In a study of the surface winds in the LV, Tapp and Hoy (2) found evidence of the drainage of air off the slopes immediately behind the sites at Giffard, Rosedale, Traralgon South,
Hazelwood and Yarragon North.
Data from the last four suggest that drainage into the main LV does occur
from both northern and southern slopes. At sites within the main part of the Valley, between Yallourn and
Rosedale, frequencies of such nights decrease from the Valley sides into the centre, averaging 11-18 per cent at
most sites but failing to approximately 6 per cent at Morwell. These frequencies appear to increase towards the east with a possible 24 per cent occurrence rate at Giffard, and
"calm" conditions being experienced at East Sale on 25 per cent of occasions.
For Loy Yang (Figure 1), two years of records obtained from a monostatic acoustic sounder have been analysed by Jones (3). These records extended up to 1000 m above the surface and indicate that nocturnal flow activity,
interpreted as the interleaving of drainage flows from the southern and northern slopes, occurred on 22 per cent of nights up to a height of 300 m
at that location.
As part of a fundamental study of slope winds, Manins and Sawford (4) investigated in the Callignee Valley (see Figure 1) the vertical structure of temperature and wind on nights when cold air drainage was pronounced.
Their findings confirm the prevalence of shallow (less than 10 m thick)
"skin" flows of cold air from most slopes sheltered from ambient winds, and also show the occurrence of deep (50 — 100 m) slope flows into the LV from the southern slopes — albeit at a much lower frequency than either the skin flows or the results reported by Jones (3) — of the order of 3 per cent
for flows which persisted for several hours.
Figure 2 shows the downslope growth of a deep slope flow on one particular night. Changes in the wind speed and t e m p e r a t u r e were considerable over 1.6 km of travel with t h e wind i n c r e a s i n g t o approximately 4 m/s at 50 m above the surface and the development of a large stable temperature gradient within the flow.
I f it is assumed that the slope flow is uniform across the slope — which is at angle a to the horizontal (a = 4° in Figure 2) — and is characterized by a speed U and thickness h then Manins and Sawford (5) showed "that, when steady conditions are achieved, U increases but h decreases more strongly with increased slope angle.
The approximate thermal energy balance is between downslope advection and heat loss at any section, and can be written as
• • . (1)
Here B is the sum of the net losses of t h e r m a l energy by l o n g - w a v e radiation and by turbulent heat transfer to the ground and to the air above from the layer of cold air, in units of buoyancy. N is the buoyancy f r e q u e n c y (or B r u n t - V a i s a l a frequency) of the ambient air near the slope — N2 is proportional to the vertical gradient of potential virtual temperature.
Equation (1) indicates that for a deep slope flow to exist the night must be reasonably cloud-free to permit cooling by outgoing long-wave
radiation from the surface and overlying air. Further, the flow is likely to be strongest soon after sunset, while N is smallest. The ambient thermal stability usually increases later in the night and Equation (1) shows that, for B approximately constant, the flow will decrease. Figure 3 demonstrates the characteristic onset of a slope wind and its gradual reduction during the night. Of course other factors also change and these influence the steadiness of the flow. The timescale for the flow to adjust to a change in external conditions is given by
ts = l/(Nsma). 4 • (2)
For the southern slopes of the LV rs is typically 2 h failing to approximately 20 min as the background stability increases during the night.
Ambient winds disrupt slope flows completely if they are strong enough, and this can be judged for a particular situation by comparing Uamb with the velocity scale of slope flows
Us< 10. (B/N) • . • (3)
Clean Air/May, 1983 29
vvhich is typically 3 m/s for the LV slopes. Another factor also is important, viz the degree of sheltering from the ambient wind a given slope has. Denoting by H the height of the ridge lines each side of a slope, Manins and Sawford (6) have shown that if the Froude number Fr —
Uamb/NH is less than 1.6, slope flows can coexist with cross slope ambient winds. If Fr > 1.6 the existence of a slope flow would then depend on the relative magnitudes of
Uamb and Us (Equation (3)) and the orientation of the direction of the ambient wind to that of the slope, as discussed in Reference (4).
It follows for the LV that the deeper slope flows from the Haunted Hills and Strzelecki Range towards Hazelwood would occur more often than flows into other regions of the Valley since the gulleys and slopes
feeding the Hazelwood region are in line with the prevailing westerlies and thus present a greater barrier to the ambient wind. Further, cold-air flows from the Thompson and MacAlister
River valleys are likelv with even stronger ambient winds because high ridges shelter these slopes.
Verification of these inferences awaits future observations.
In steady conditions a slope flow attains a force balance between the excess vveight of air acting down the
slope and the momentum exchange due to mixing between this air and the
air above. On slopes which are heavily treed, surface drag is also important.
This balance has the effect of arresting the drop in temperature of the layer at
any plače on the slope, as is evident in Figure 3 after ca 1830 h. The deficit in temperature, A0, between the slope
flow and the ambient air is then given by (see References (4), (5))
» • (4)
Here F is proportional to the square of the change in velocity between the flow and the air above. Knowledge of the temperature deficit is important (see below) and its strong sensitivity to the velocity change means that it is a very difficult quantity to predict accurately.
Consider how flows of cold air from the side slopes and gulleys feed into the LV. Air on the slopes loses heat to space and to the ground at much the same rate as that on the floor of the Valley. However once these flows are set up, equilibrium (Equation (4)) is approached on the slopes, unlike the situation on the Valley floor where an ongoing drop in temperature occurs.
In addition to data for the Callignee slope, Figure 3 also indicates the simultaneous temperature history for three Valley sites. Rosedale and East Šale experienced throughout the night
1) DROUIN M LEONGATHA 7) M0RWELL 10) ROSEDALE 2) WARRAGUL 5) MOE 8) TRARALGON 11) ŠALE
3) KORUMBURRA 6) YALL0URN 9) CALLIGNEE VALLEY 12) GIFFARD
Figure 1. Chart showing the locations of significant features and observing sites in the Latrobe Valley. YN — Varragon North, YMO — Yallourn MO, YFO — Yallourn FO, MCC — Momvell CC, LY — Loy Yang, OLY — Old Loy Yang, TS — Traralgon South, ES — East Šale, H —Hazelvvood. Contour intervals are 0, 200, 500,1000 metres above m.s.l.
decreases in t e m p e r a t u r e characteristic of open plains but at Traralgon South, being directlv under the influence of the southern slopes, the temperature had practically stablized by midnight.
The res uit is that the coldest air is to be found on the Valley floor. The drainage winds tend to flow over this air to form a complex interleaving of layers. These occasionally break dovm due to shear instabilities, and mix to ground level as has evidently been
found by Jones (3). Town and car emissions are trapped below or in
these layers. Since the Strzelecki Range is closer to the centre of the LV and has shorter slopes which are less heavily treed (hence less mixing) than
the northern Range, flows from the northern side vvould tend to be warmer. This is supported by Figure 4, an interpretation of infra red
photographs on a calm clear night due to Moriarty (7). It shows that the warmest air is to be found at the mouth of the MacAlister River valley and the coldest air near Traralgon along the Latrobe River.
Impingement of chimney plumes onto the hills of the L V and their subsequent recirculation in drainage flows back to the floor of the Valley has been raised as a possibility (e.g.
Moriarty (7)). Given the low frequency of occurrence of deep slope flows this would be 'a rare event, requiring extended periods of calm to
30 Clean Air/May, 1983
complete the path. It is even less likely for the northern Range than the Strzelecki slopes since the former are further from pollution sources. In any event the material so recirculated would be unlikely to contribute to nocturnal pollution events because of the layering mentioned above, although an hour or two after sunrise, when diurnal heating would be under way, the elevated pollutants would fumigate to the ground (Manins (8)).
MESOSCALE CIRCULAT10NS. In
his study of high pollution events in the LV, Moriarty (7) found an association with (perhaps strong) upper level winds (1000 m) with a northerly component. In many nocturanal and early morning cases the Froude number, Fr — Uamb/NH (with H now the height of the Strzelecki Range), was small enough, mainly because of large low-level thermal stability, to suggest blocking of the wind to height H. Moriarty suggested that a circulation would be set up below the height of the Range downwind, driven by the upper flow.
Emissions embedded in this system could be recirculated back over the main Valley, possibly at lower levels.
They would then be fumigated to ground level during the morning heating cycle. The mechanism is viable even when the high pressure svstem to the north-east of the Valley, generating the ambient winds with northerly component, has associated strato-cumulus cloud over the Valley.
This often occurs, obviating the participation of significant slope flows
in the movement of pollutants.
Support for these ideas comes from three sources — the direct observation of blocking (on a smaller scale) by Manins and Sawford (6), the early morning soundings reported by Spillane and Wren (9), and a recent set of laboratory experiments performed by the present writer.
A 1 600 000: 1 scale model with 60 : 1 vertical exaggeration was used in a simulation of the thermally stably stratified flow over Victoria with the ambient wind having a northerly component. Salt-stratified vvater was used as the working medium with the motion in the LV made visible by injecting neutral buoyancy dye into the region at a scale height of 200 m.
W i t h a F r o u d e n u m b e r of approximately 0.3, the observations can be summarised as follows.
Northeasterly wind: A circulation developed in the central LV with a weak westerly experienced near YalIourn. Minor changes in imposed conditions led to stagnation near
Morwell with weak westerly to southwesterly winds along the Morwell River.
Figure 2. Sample simultaneous observations of slope winds in the Callignee Valley. The lovver site is 100 m above the floor of the main Lat robe Vallev. V g wi s t h e easterly wind component, UNS is the northerly wind component, and OV is the potential virtual temperature.
Figure 3. Observations at the lovver of two sites in the Callignee Valley showing wind direction and speed (2 m height) and temperature (3 m height). For comparison temperatures measured simultaneously at three LV sites are given: TS — Traralgon South, R — Rosedale, ES — East Šale.
Northerlv wind: a very variable weak circulation in the main LV resulted, with conditions changing
from stagnant to easterlv to westerly depending on minor changes in imposed circumstances.
Northwesterly winds: The winds in the LV were initially westerly but soon stagnated and reversed to give easterly winds throughout the main Valley.
The last result was particularly striking and was due, in the experiments, to a large anti cyclonic eddy which formed in the lee of the Great Dividing Range and centred off the coast. Observations in the actual LV are in agreement with this result.
Figure 5, taken from Reference (10) shows the correlation between the wind direction at 1000 m and that in the layer 100 to 150 m above ground level, for ali days of the Loy Yang soundings reported by Spillane and Wren (9). Besides the prevalence of easterly or westerly winds in the early morning simultaneously at both levels, there was a considerable number of
occasions when the upper level wind was between north and west and yet the lower level wind had an easterly component.
In a c t u a l i t y the o b s e r v e d 'decoupling
1of the wind with height
Clean Air/May, 1983
