BLANkET Technical Report – 1

A general description of the BLANkET project

(Base-Line Air Network of EPA Tasmania) –

Aims, methodology, and first results

November 2009

The Minister for the Environment, the Hon. Michelle O’Byrne, inspects a BLANkET station with an

officer of the Air Section Environment Division, at the official launch of the BLANkET network at

Lilydale, north-east Tasmania, on the 12th

May 2009.

A general description of the BLANkET project

(Base-Line Air Network of EPA Tasmania) –

Aims, methodology, and first results

Summary: A description is given of the Base-Line Air Network of EPA Tasmania (BLANkET). The aims

of the project are described, along with the station instrumentation. Example data from the first few

months of operation of five stations are also presented, along with some early analysis.

Rationale: In early 2009 the Tasmanian Environment Protection Authority approved funding for a

new air quality monitoring network for Tasmania. This network, BLANkET (Base-Line Air Network of

EPA Tasmania) consists of low-cost indicative air monitoring equipment that is generally located in

regions away from the major cities of Launceston and Hobart, but in areas near where forest

industry and other bodies and agencies conduct planned burns. These burns are carried out, usually

in the autumn, for forest regeneration, for environmental management, for the removal of forest

residue following harvesting, for fuel reduction, and for other reasons.

The scale of these autumn burns is significant. It was recently estimated that between March and

June in 2008 some 31,000 hectares of forest industry burning took place, consuming upward of 7

million tonnes of forest logging residue.

Such a large total fuel burn necessarily produces a correspondingly large amount of smoke. Forest

industry burning is carried out according to a series of protocols and guidelines that aim at

minimising smoke impacts on population areas. These take into account the forecast meteorological

conditions, and (since 2009) establish a cap on the amount of burning permitted in a given region of

the state on a given day.

Despite such guidelines, significant amounts of smoke can and do impact on the state’s population.

In autumn 2008 there were recorded episodes of several days duration where planned burn smoke

reached the major cities of Hobart and Launceston and significantly reduced air quality. High particle

(smoke) levels were seen simultaneously at Launceston and George Town (40 km north-west of

Launceston) during some of these events, indicating a wide spatial scale of the smoke. A visual

indication of the scale of the burning and of the resulting smoke plumes can be seen in satellite

images of Tasmania in April and May 2008, shown in Figures 1 to 3. Satellite images such as these do

not provide a measure of smoke impact at ground level, but they do clearly show the large-scale of

the plumes and the distance that smoke can travel from the source. Figure 4 shows PM2.5 and PM10

measurements (particles up to 2.5 millionths of a metre and particles up to 10 millionths of metre

respectively) made at Hobart in April 2008. There were significant smoke impacts on the 11th

, 19th

,

20th

, 23rd

, 24th

and 25th

of April due to planned burns. There were similar smoke impacts measured at

Launceston and George Town.

The current management of smoke from planned burns in the state is limited by inexact knowledge

of smoke movement and dispersal in the greater Tasmanian airshed as a whole, and on medium-

and small-topographic scales in particular. Historically, air quality data are generally only available

from Launceston and Hobart (and since 2007 from George Town and Rowella in the lower Tamar

valley). Hence planned burn smoke impacts away from these centres have not been quantified.

Additionally a full management strategy should also take into account existing air quality in each

region before authorising further burns on any given day.

Figure 1 - MODIS image of north-east Tasmania, 17th

April 2008

Figure 2 - MODIS image of Tasmania, 20th April 2008

After the 2008 burning season was completed, the Air Section of the Environment Division

commenced work on designing a more broadly based air monitoring network for Tasmania that

could address the above issues. This resulted in the formulation of the BLANkET concept.

Independently, a survey of monitoring methods used elsewhere (mostly overseas) was

commissioned by the Environment Division and conducted by Williamson and Bowman (University

of Tasmania). There was considerable overlap in the outcomes of these two independent

approaches.

Scope of project: Depending on the final configuration, BLANkET will consist of around 16 fixed

stations, each containing an indicative air quality instrument, a meteorological station, and a

communications link. The stations will report data automatically every 10 to 15 minutes. The data

will be published almost immediately on a publicly accessible web page. The provision of real-time

air quality data will assist with the management of smoke from planned burns, as well as being a

valuable public information tool. The stations will operate year-round, and will also provide

measurements of winter-time smoke concentrations from domestic heating, as well as monitoring

summer bushfire smoke.

Figure 3 - MODIS image of north-east Tasmania, 13th May 2008

Two areas of the state have been selected for the first BLANkET station deployments, based on their

proximity to regions of planned burn operations. These are the North-East, where up to seven

stations will be located, and the South (Huon and Derwent valleys), where up to six stations will be

sited. These two regions were chosen for detailed study to give clusters of stations suitable for

understanding smoke movement and dispersal in a given airshed. This would not be possible if the

stations were distributed more evenly over the whole state. Additional stations are planned for the

North-West coast (for example in or near Burnie). The network may be extended to cover other

areas of the state in future.

Figure 4 - Hobart PM2.5 and PM10 air quality data, April 2008.

Figure 5 shows the existing major air stations at Hobart, Launceston, Rowella and George Town, the

proposed major air station at Devonport, and a possible configuration of the BLANkET sites. The

BLANkET sites are shown as triangles. The first five stations, located in the north-east, were

deployed in May 2009 (Lilydale, Scottsdale, Derby, St Helens and Fingal) and have been in near

continuous operation since then. The proposed southern sites, and a site near Burnie, are also

indicated. At least two other sites are planned for the north-west. Preparations for the deployment

of the proposed stations are well advanced as at late 2009.

Equipment requirements: In order for the network to operate successfully each station needed to

be equipped with an air quality instrument capable of continuous measurement (preferably sub-

hourly time resolution), a meteorological station, and a communications link. The equipment had to

be securely housed and to require only basic maintenance to operate under automatic control for

long intervals. Low total power consumption and a small footprint were considered significant

advantages. The overall cost of each station needed to be as low as possible to allow the maximum

number of stations to be deployed, given the fixed budget.

Figure 5 - Present and proposed air monitoring stations in Tasmania.

Early on in the formulation of the project it was realised that a continuous reference instrument,

such as a Tapered Element Oscillating Microbalance (TEOM™, which are operated at several of

Tasmania’s air stations) or Beta Attenuation Mass measurement instrument (BAM™), would be likely

to require a substantial expenditure on supporting infrastructure (e.g. air conditioned enclosure),

and have significant power and maintenance and resource needs, while providing only hourly time

resolution. In contrast, several years experience with a small optical particle counter (a TSI 8520 Dust

Trak™) at Launceston had shown that a relatively small-cost, low-power, low-footprint instrument

could give a very good indicative (proxy) measurement of PM2.5. This is shown in Figure 6, where

data from Launceston air station from February to May 2008 are shown. The red squares are 24-

hourly data from the reference PM2.5 low volume air sampler. The upright crosses are proxy PM2.5

data from day-averaged data from the 8520 Dust Trak™ (optical particle counter). To a good

approximation, the proxy PM2.5 values, derived from the day-averaged Dust Trak™ reading, gives a

reliable measure of PM2.5. Data collected with such an optical instrument are not mass

measurements, but are a proxy based on a measured particle count and a calibration from counts to

mass for the particular aerosol under study.

Figure 6 - Launceston air quality data, February to May 2008: Low-Volume Air sampler PM2.5 (red squares)

and day-averaged 8520 Dust Trak™ reading (upright crosses). (The peak in mid March was due to smoke

from a bushfire in north-west Tasmania. Elevated levels in April and for some of the May days are ascribed

to smoke from planned burns.)

It is likely that such a good correlation exists at Launceston, at least in part, because a significant

fraction of Launceston’s PM2.5 particles are from wood smoke. Wood smoke particles are typically

very small, under 1 millionth of a metre (and hence would be classed as PM1). Optical particle

counters tend to be more sensitive to smaller particle, due to the nature of light scatter from

aerosols. Hence in some measure the correlation above is possibly due to the dominance of PM1

particles in the PM2.5 fraction.

The TSI Dust Trak™ in operation at Launceston is compact, uses very little power, and demonstrably

gives usable, albeit indicative, PM2.5 measurements in the Tasmanian context. It was decided that

serious consideration should be given to basing the BLANkET network around such a device.

Several other optical particle counters are commercially available. A market survey was undertaken

to investigate the suitability of the various instruments of this type. The result of the survey, which

also included field evaluations of two instrument types, was that the newly released 8533 DRX Dust

Trak™ from TSI was selected for the BLANkET project. This device, with an in-built data memory,

offered several advantages over competing instruments. The 8533 DRX™ is a network enabled

device, providing a simple and direct means of communicating with the instrument remotely. The

instrument provides estimates of PM1, PM2.5, PM4, and PM10. While some other instruments can also

provide this in the one package, the TSI device can be field calibrated by the operator and provides a

greater measure of flexibility in this process, allowing the PM2.5 and PM10 channels to be (effectively)

decoupled. This is important in Tasmania, where PM2.5 is mostly composed of smoke aerosols which

are generally less than 1 millionths of a metre in effective diameter, while the coarse fraction of

PM10 (those particles over 2.5 millionths of metre but less than 10 millionths of a metre) appears to

consist mostly of sea-salt aerosols. The decoupled channels of the 8533 DRX™ effectively allow the

instrument to simultaneously measure both the smoke and the non-smoke aerosols with

appropriate scatter-to-mass calibrations.

Figure 7 - A comparison of day-averaged DRX data (blue symbols) and gravimetric (low volume air sampler)

data (red symbols) for Hobart, April to June 2009. Top panel: PM10; Lower panel: PM2.5.

The field performance of the 8533 DRX™ has been satisfactory. Figure 7 shows for New Town station

(Hobart) day-averaged 8533 DRX™ data for PM10 and PM2.5 (blue symbols) compared with

gravimetric PM10 and PM2.5 data from reference low-volume air samplers (red symbols), for April to

June 2009. In general, the agreement is good to a few µg m-3

. These data were in fact used to

improve the calibration of the DRX™ which had initially been derived from TEOM™ data for PM10 and

8520 Dust Trak™ data as a proxy for PM2.5.

One possible confounding signal that arises when using optical scattering methods is the presence of

high-humidity in the sample air, with the most extreme case being fog. Scatter from water droplets

can mimic that from smoke or other aerosols, hence optical measurements taken under these

conditions can overestimate the true PM signal. Early experience at Launceston with the older

model 8520 Dust Trak™ showed this effect. To overcome this, the air being passed to the Launceston

Dust Trak™ was preheated by drawing the sample air through a heated aluminium tube. This raised

the temperature of the air sample, decreasing the relative humidity, and hence preventing the

contamination of the measurement. Figure 6 above shows results taken with the heater inlet in

operation at Launceston. Consequently, heated inlets were designed and built by Environment

Division staff and were installed in the BLANkET stations.

The specifications of the 8533 DRX state that temperature-induced drift in the measured PM signals

is low (near 1 µg m-3

per degree C). To remove the effect of this drift, a TSI autozero module is used

hourly to monitor and correct for base-line drift in the zero-level.

A suitable meteorological station was also required. A variety of such stations are commercially

available, with a corresponding wide range of costs. It was realised there while there were

advantages in using a ‘high-end’ meteorological stations, it was decided that, given the air quality

data would be ‘indicative’ rather than reference-quality data, there were significant cost advantages

in selecting a basic, albeit robust and reliable, meteorological installation. The Davis Vantage Pro2™

station was chosen after a comparison of available systems. The Davis WeatherlinkIP™ datalogger

and software was used to provide on-board data storage and network IP communications.

Network communications to the stations was also an issue of active consideration. The Cybertec™

Series 1000 (model 1220) 3G modem router was selected for the stations, again after a market

survey and discussion with vendors and equipment suppliers. The Cybertec™ 1220 was

recommended by Kenelec Scientific (see below) as a possible solution for BLANkET. The Cybertec™

1220 has two LAN ports and three network addressable RS-232 ports, as well as two digital-in and

two digital-out data lines. In the station configuration, the 8533 DRX™ is addressed via a LAN port,

the Davis Vantage Pro2™ meteorological station is addressed via an RS-232 port, and the digital I/O

lines are used for instrument control and monitoring. More details of this are provided later in this

report.

The station modems have a fixed IP address within the Tasmanian State Government firewall.

System Overview: After the selection of equipment had been finalised, the individual components

needed to be integrated into a complete operating station. Kenelec Scientific in Melbourne, the

Australian agent for the TSI Dust Trak™ instruments, was engaged to carry out the system

integration design, construction, assembly, and initial testing.

The individual components are mounted in an external-grade metal electrical meter box 9800 x 600

x 300 mm). Main power is supplied (via an earth-leakage protected line) to a 14 V battery

charger/voltage regulator, which trickle charges a 30 Amp-hour 12 V battery. The DRX™ and modem

are run directly from the battery, with a 12 V relay in-line for the DRX. A DC-DC converter provides 5

V for the Davis meteorological station. The relays are under the control of the one of the digital-

output lines of the modem, allowing power to be cycled on the components via remote control. In

practice the Davis Vantage console is also provided with C-cell battery backup, as if it loses power its

power-on state does not allow remote network access without an operator being present to provide

a reset via a front panel button.

The air inlet heater is also run from a 12 V signal via a second relay, which is under the control of the

other digital output line of the modem. This was provided only as a fail-safe in case the heater servo

system failed in a run-away mode. Additional fail-safe devices on the heater include an in-line

thermostat that turns off the heater when the in-box temperature is above 30 C, and a sacrificial

thermal fuse on the inlet itself that will break the electrical circuit if the heater temperature rises

above 70 C.

The modem can be reset by sending it a specific SMS message.

The inlet of the sample line exits the box top and is turned in a gentle curve to point downwards. It is

protected from rain and insect ingress by an inverted stainless funnel and a fine wire mesh.

An image of an assembled system, deployed in the field, is shown in Figure 8. The principal

components are identified. A general view of a BLANkET station, showing the inlet tube,

communication antenna, meteorological station, and earth-leakage protected mains power supply,

is given in Figure 9.

Software for communication, data reporting and analysis, and web publication: The early concept,

subsequently implemented, was that the communications and data-reporting requirements of

BLANkET would be met through purpose written software. The main reason was to ensure the final

system would meet the requirements of the project, and be easily extendible to meet future needs.

The data-analysis software language IDL™ (Interactive Data Language, from ITT Visuals) provides a

full development environment for a high-level scientific language that is capable of network

communications. The syntax is FORTRAN-like, and is easily learnt.

Communication with the modem at a given station is via calls to an internet SOCKET command. The

modem is configured to port forward to either the DRX or the met station, depending on which port

is specified in the socket call. This allows command strings to be sent to either device for control,

configuration changes, or data retrieval. In IDL communication across the socket is via virtual files.

IDL also provides tool for creating graphical user interfaces (GUIs). Data-logging control for BLANkET

is via a purpose written GUI (known as a widget in IDL). This allows for control of data collection by

staff not familiar with IDL programming.

The software runs on a PC at the Hobart offices of the Environment Division. All data from the

network are retrieved via this PC. Live copies of the data are kept on a server disk as backup.

In outline, every 10 minutes the software ‘wakes’ and polls the stations based on a text listing of

station names and IP addresses. Communication to each listed station is attempted in turn. If

successful the status of the 8533 DRX is determined, and air quality and error status data is read

back. A similar process is followed for the meteorological data at each station. Any errors in

communication or instrument error-status issues are logged into a daily text file for diagnostic

purposes. These daily files are automatically updated on the server disk after each read.

Figure 8 - A BLANkET station as deployed in the field.

Figure 9 - General view of a BLANkET station.

Data from the DRX and meteorological instruments are written to a daily file. A plot of these data is

generated and displayed on the data-logging PC. The plot files are also written to the server disk

after each data read, as well as being copied to a web server for public viewing.

At the first read of a new day a new daily file is created for the DRX data, the meteorological data,

and the daily logging information (containing status and error message).

In its original implementation there was no automatic means to retrieve data if a communications

gap (due to network issues) prevented the software from reading a given station at a given time.

However, both TSI and Davis supply software that allows manual retrieval of logged data on the

DRXs and Vantage Pro2 instruments. Hence any data lost due to network outages could be and was

retrieved by this means.

At the time of writing the data-acquisition software is being significantly upgraded to provide a more

systematic approach to data collection, to allow an easier means of configuring both the DRX and

meteorological instruments, to log more system performance parameters, and to enable an

automatic (daily) download of logged data.

A screen shot of the data-logging PC in operation at the Hobart Environment Division offices is given

in Figure 10.

Installation of first stations: Funding for the BLANkET project was approved in mid February 2009.

Final component selection and system design and integration (by Kenelec Scientific) was then

completed, orders were placed and construction started. Work also commenced on the data logging

software. Additionally site selection visits were undertaken and various regional councils and other

landowners contacted to investigate the feasibility of locating BLANkET stations in suitable areas.

Support from the councils was excellent, and five sites in the north-east of the state were made

available. Kenelec Scientific also expedited the work, and in mid April the first stations were

delivered to Hobart. Site works (trenching, electrical connections) also was completed in April for the

five north-east sites. Final system assembly and testing was carried out in late April in Hobart. The

first two stations were deployed (to Derby and Lilydale) on the 6th

of May, just under 3 months from

project approval.

One week later, on the morning of the 13th

of May, the Minister for the Environment, the Hon.

Michelle O’Byrne, officially launched the BLANkET programme at Lilydale station. That afternoon the

Scottsdale BLANkET station was installed. On the 20th

of May Fingal and St Helens stations were

installed.

Figure 10 - Screen shot of the data-logging PC.

Due to other commitments the pace of development of the BLANkET network could not be

maintained. It was decided to continue site selection and preparation, but to not deploy further

stations as the autumn burning season was effectively completed. The five deployed stations were

to be operated as a mini-network to gain experience with the operation of the DRX in the field and

to assess the performance of the system as a whole. Very valuable experience and understanding

has been obtained as a result of this, as discussed in the next section.

At the time of writing (October 2009) work is well underway for further station deployments. It is

expected the full network will be operational early in 2010.

The first months of operation: In general system performance from the five north-east stations has

been acceptable. Some minor debugging of and improvement to the data-logging and data-display

software has been implemented, but in general the software has performed satisfactorily. The

station enclosures (meter boxes) have proved secure against rain (which was well tested by an

extended interval of wet weather in Tasmania in winter 2009).The Cybertec modems also have

proved reliable, and have almost always recovered from network outages – at times we have seen

two or three stations drop off the network simultaneously, indicating the problem in these cases is

not local to a particular modem.

Some revision of the heated inlet design was also undertaken in response to what initially appeared

to be evidence for fog or high humidity affecting the measured PM levels, as seen by a correlation

between relative humidity and measured PM10. The heater set temperatures were raised from 60 C

to nearer 70C for some units. A more effective means of heating the incoming air was devised by

bending the inlet line into a gentle ‘S’, allowing a longer residence time in the heated pipe, and

fabricating it from copper rather than stainless steel at one station, and applying thermal insulation

along the entire length of the sampling tube inside the enclosure, resulted in significantly greater

heating of the sampled air. The temperature of the air exiting the DRX was measured to be at least

10 C above ambient after these changes. There was however no apparent affect on the data.

Subsequent investigation now points to the correlation between relative humidity and measured

PM10 as being due to the presence of sea-salt aerosols (whose growth rate depends on relative

humidity), brought inland during an extended interval of moderate easterly winds. Further

discussion of this event is contained in a separate BLANkET report.

Further tests of the sensitivity of the DRX to fog were conducted by placing a DRX in a car, sampling

outside air via a length of tubing, and driving in and out of fog banks on a cold (near freezing) night

in north-east Tasmania. In this case the only heating applied to the incoming air was from keeping

the car interior near 25 C. No increase in signal was seen in either PM10 or PM2.5 as the DRX sampled

foggy air. Indeed, both PM10 and PM2.5 showed decreases at these times. There is evidence to

suggest that certain types of fog can scavenge aerosols from the air and deposit them on the

ground. This appears to be an explanation for these data.

At one station on a very cold night (minimum near -5 C) a sudden and variable increase was seen in

the PM data during the coldest part of the night. It was hypothesised that ice crystals were being

transported into the scattering chamber and giving rise to the increased signal. A few days after this

the box was lined with foam insulation, which raised the internal temperature by about 5 C on these

cold nights, enough to keep it above the freezing point. No further episodes were seen of large and

variable signal correlated with cold temperatures. The other stations enclosures were similarly

insulated shortly afterwards.

Example data: Figure 11 shows seven days of BLANkET air quality (top panel) and meteorological

data (lower panel) from Lilydale station form June 2009. Figure 12 shows the equivalent interval for

Derby station. In the top panel PM10 is shown as blue triangles; PM2.5 is shown as red squares. In the

lower panel, air temperature is shown as blue triangles, wind speed as red squares, wind direction as

orange upright crosses, and relative humidity as brown diamonds. Cumulative rain for the day, if

present, is shown by the black symbols.

An interval of high PM2.5 is the signature of the presence of smoke (for example on the nights on the

16th

and 17th

of June at Lilydale). During these times if PM10 is very similar to PM2.5 then smoke is the

dominant aerosol present. For the data interval shown here the smoke is almost certainly from

domestic wood heaters. At other times PM10 can be significantly higher than PM2.5, such as is seen at

both stations during the 20th

of June. This is the signature of aerosols (larger than smoke particles)

such as dust or sea-salt aerosols. Note the sudden drop in PM10 at both stations the commenced

right at the end of the 20th

and coincided with rain falling at both Lilydale and Derby. The

interpretation is that the bigger aerosol (dust or sea-salt) was either washed out of the air by the

rain, or the rain-bearing air mass that moved over the stations had much lower levels of aerosol

loading. Similar signatures were also seen at the major Tasmanian air stations at Rowella, George

Town, Launceston and Hobart. A report into a similar event in late May 2009 is presented elsewhere.

It should be noted, as show here, that PM2.5 (smoke) levels are substantially higher on average at the

Lilydale station than at the Derby station. This was initially unexpected, given that the Lilydale

station is nearly 1 km from the town centre, while the Derby station is located right on the southern

end of Derby, adjacent to residences. Investigations carried out at both locations on several nights

showed that under synoptically calm conditions, katabatic drainage flows were established that at

Lilydale brought smoke from township down a small creek valley to the air station, but at Derby

moved house smoke away from the station into the town itself. (These studies are described in

more detail elsewhere).

A survey in Derby itself, using an 8533 DRX in a passenger car, showed extremely high levels of

smoke in the town on calm nights. An example of this is shown in Figure 13, from the evening of the

23rd

of July 2009. The first 5 minutes of this plot from 23:25 to 23:31 AEST (i.e. 11:25 pm to 11:31

pm) shows measurements made at the location of the Derby BLANkET station on the southern edge

of town. PM2.5 varied between 10 and 15 µg m-3

. A sample immediately afterwards through Derby

along the main street (Tasman highway) gave a peak PM2.5 reading near 110 µg m-3

just before 23:35

AEST. Smoke levels cleared rapidly to below 5 µg m-3

once the end of the town was reached.

Sampling was recommenced out of the northern end of the town near 23:45, with another transect

through the town (this time in the opposite direction) just before 23:49. A peak PM2.5 level near

90 µg m-3

was recorded near the town centre on this pass. Further surveys are planned.

Another significant event detected by BLANkET was a dust storm on the 12th

of September. This was

actually 3 separate storms on successive day, with the third (on the 12th

) being the biggest. The DRX

scatter-to-mass calibration may not be strictly applicable to dust, but the event was clearly seen by

the BLANkET network (see Figure 14). This event is also discussed in more detail elsewhere.

Figure 11 - BLANkET data from Lilydale station, 15th

to 21st

June 2009. Top panel: Air quality data; Lower

Panel: meteorological data.

Figure 12 - BLANkET data from Derby station, 15th

to 21st

June 2009. Top panel: Air quality data; Lower Panel:

meteorological data.

Figure 13 – Air quality data from two transects of Derby, north-east Tasmania, on the evening of the 23rd

of

July 2009.

The main aims of the BLANkET programme are to monitor smoke from planned burns, to provide a

real-time measure of this smoke, and to contribute to the understanding of how smoke moves and

disperses in the Tasmanian airshed. Although the BLANkET stations were only established in the last

few weeks of the usual planned burn season, the network did appear to detect several instances of

planned burn smoke arriving at a station. The analysis of these data is underway and will be

reported at a later date.

Summary: The basic concept of the BLANkET network has proved feasible and the mini-network of

five stations in the north-east of Tasmania has generally operated successfully since May 2009.

Much valuable experience and information has been obtained as a result of this. The system appears

capable of discriminating between smoke and naturally occurring particles such as dust and sea-salt

aerosols.

Refinements to and improvements of the data collection software are also in hand. Work is well

underway to deploy the remaining stations before the 2010 autumn burning season to deliver a fully

functioning air quality network, covering a substantially greater spatial scale than has been hitherto

possible in Tasmania.

Acknowledgements

This project could not have been undertaken without clear and strong support from the EPA board,

the Minister for the Environment, and the General Manager of the Environment Division. We thank

the many Environment Division Officers who have worked wonders to allow the project to proceed.

It is a pleasure to acknowledge the support and design knowledge of Kenelec Scientific. Support

from, and contributions by, local councils and water boards have also been vital for the programme’s

progress. We acknowledge the use of MODIS satellite images.

Report compiled by John Innis.

Figure 14 - The 12th

of September 2009 dust storm as recorded by the north-east Tasmanian BLANkET

stations.