Emission sources identified in Huon Study

Aug 24, 2011
Emission sources identified in Huon Study
Tasmanian study tracks fire emission sources in an air quality assessment in the Huon Valley. Credit: Willem van Aken, CSIRO

Emissions from domestic wood-fired heaters in southern Tasmania's Huon Valley dwarf emissions from forest regeneration burns, according to a new CSIRO study.

"Smoke plume events from prescribed burns do impact the and occasionally exceed the 24-hour standard concentration for particulates but wood-fired heater lead to particulate concentrations that are seven times greater than those from prescribed burns," said and project lead author, Dr. Mick Meyer.

"These results may surprise some residents but our studies found that although the intensity of emissions from and residential wood heaters was similar, emissions from wood heaters contributed 80 per cent to the atmospheric fine particle load, compared to 11 per cent from regeneration burns. The remaining 9% was from fires lit by local landowners.

"Our study has shown a bigger impact on air quality at Geeveston than at Grove, indicating that particulate concentrations are influenced by local sources such as wood heaters rather than regional pollution."

The air quality study was commissioned by Forestry Tasmania after widespread complaints by Huon Valley residents about autumn regeneration burn-offs. The study is the first intensive air quality study in the valley and involved atmospheric monitoring at Geeveston and Grove.

Dr. Meyer said smoke from prescribed burning has been a subject of public debate as a major cause of pollution events, although there have been few data available to quantify its significance.

"We monitored air quality at two sites based on fine and coarse between March, 2009 and September 2010.

"This monitoring clearly showed that at times measurements exceeded the national standards, particularly at times of prescribed burn-off and during winter when woodheaters are used. Emissions from residential heaters were the largest source of air-borne particles, contributing 80 per cent to the emissions load."

Woodheaters, and open burning on private land, emit smoke into the lower atmosphere (up to 1000 meters) where dispersion is poor. Regeneration burns are more complex; they are intended to produce an intense localised fire which consumes the heavy fuel load and generates a strong convection column that rises through the mixing layer and ideally into the free troposphere where smoke disperses out of the airshed.

The plume of smoke from a prescribed burn diminishes once fine and coarse fuels are consumed and burn intensity declines. The heavy fuels can burn for hours and days, but smoke remains near the surface and dispersion is limited.

Co-author, Dr. Fabienne Reisen, said emission impacts from burn-offs are short, ranging from several days to a week, with higher peak concentrations than wood-fired heater smoke.

"On the other hand, impacts of wood smoke from residential burning are of longer duration and particle concentrations often remain elevated for periods of months. These can be further impacted by unfavourable meteorological conditions such as temperature inversions in which smoke is trapped in valleys," Dr. Reisen said.

Explore further: Avoiding ecosystem collapse

add to favorites email to friend print save as pdf

Related Stories

Device burns fuel with almost zero emissions

Jun 21, 2006

Georgia Tech researchers have created a new combustor (combustion chamber where fuel is burned to power an engine or gas turbine) designed to burn fuel in a wide range of devices - with next to no emission ...

Prescribed burns may help reduce US carbon footprint

Mar 17, 2010

The use of prescribed burns to manage Western forests may help the United States reduce its carbon footprint. A new study finds that such burns, often used by forest managers to reduce underbrush and protect bigger trees, ...

Daily forecasts track smoke from southern fires

May 30, 2007

At the request of the Georgia State Department of Health, scientists with the Southern Research Station Smoke Management Team located at the Center for Forest Disturbance Science in Athens, GA, are producing daily smoke forecasts ...

Recommended for you

Avoiding ecosystem collapse

9 minutes ago

From coral reefs to prairie grasslands, some of the world's most iconic habitats are susceptible to sudden collapse due to seemingly minor events. A classic example: the decimation of kelp forests when a ...

Global warming cynics unmoved by extreme weather

50 minutes ago

What will it take to convince skeptics of global warming that the phenomenon is real? Surely, many scientists believe, enough droughts, floods and heat waves will begin to change minds.

New tool displays West Coast ocean acidification data

1 hour ago

Increasing carbon dioxide in the air penetrates into the ocean and makes it more acidic, while robbing seawater of minerals that give shellfish their crunch. The West Coast is one of the first marine ecosystems ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

RobertKarlStonjek
1 / 5 (1) Aug 24, 2011
The image above shows a bush fire (wild fire) and not a regeneration burn which only occurs where trees have already been felled and cleared and only branches and undergrowth remain.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.