Fine particle emissions from tropical peat fires decrease rapidly with time since ignition
Author(s)
Type
Journal Article
Abstract
Southeast Asia experiences frequent fires in fuel-rich tropical peatlands, leading to extreme
episodes of regional haze with high concentrations of fine particulate matter (PM2.5) impacting human
health. In a study published recently, the first field measurements of PM2.5 emission factors for tropical peat
fires showed larger emissions than from other fuel types. Here we report even higher PM2.5 emission factors,
measured at newly ignited peat fires in Malaysia, suggesting that current estimates of fine particulate
emissions from peat fires may be underestimated by a factor of 3 or more. In addition, we use both field and
laboratory measurements of burning peat to provide the first mechanistic explanation for the high variability
in PM2.5 emission factors, demonstrating that buildup of a surface ash layer causes the emissions of PM2.5 to
decrease as the peat fire progresses. This finding implies that peat fires are more hazardous (in terms of
aerosol emissions) when first ignited than when still burning many days later. Varying emission factors for
PM2.5 also have implications for our ability to correctly model the climate and air quality impacts downwind
of the peat fires. For modelers able to implement a time-varying emission factor, we recommend an emission
factor for PM2.5 from newly ignited tropical peat fires of 58 g of PM2.5 per kilogram of dry fuel consumed (g/
kg), reducing exponentially at a rate of 9%/day. If the age of the fire is unknown or only a single value may be
used, we recommend an average value of 24 g/kg.
Plain Language Summary This paper provides evidence that peat fire emissions of fine
particulates are much larger than for other fires when the peat is newly ignited but decrease rapidly as the
fire progresses. This is important because it means that newly ignited fires are particularly detrimental to
ambient air quality in impacted regions.
episodes of regional haze with high concentrations of fine particulate matter (PM2.5) impacting human
health. In a study published recently, the first field measurements of PM2.5 emission factors for tropical peat
fires showed larger emissions than from other fuel types. Here we report even higher PM2.5 emission factors,
measured at newly ignited peat fires in Malaysia, suggesting that current estimates of fine particulate
emissions from peat fires may be underestimated by a factor of 3 or more. In addition, we use both field and
laboratory measurements of burning peat to provide the first mechanistic explanation for the high variability
in PM2.5 emission factors, demonstrating that buildup of a surface ash layer causes the emissions of PM2.5 to
decrease as the peat fire progresses. This finding implies that peat fires are more hazardous (in terms of
aerosol emissions) when first ignited than when still burning many days later. Varying emission factors for
PM2.5 also have implications for our ability to correctly model the climate and air quality impacts downwind
of the peat fires. For modelers able to implement a time-varying emission factor, we recommend an emission
factor for PM2.5 from newly ignited tropical peat fires of 58 g of PM2.5 per kilogram of dry fuel consumed (g/
kg), reducing exponentially at a rate of 9%/day. If the age of the fire is unknown or only a single value may be
used, we recommend an average value of 24 g/kg.
Plain Language Summary This paper provides evidence that peat fire emissions of fine
particulates are much larger than for other fires when the peat is newly ignited but decrease rapidly as the
fire progresses. This is important because it means that newly ignited fires are particularly detrimental to
ambient air quality in impacted regions.
Date Issued
2018-05-27
Date Acceptance
2018-04-13
Citation
Journal of Geophysical Research: Atmospheres, 2018, 123 (10), pp.5607-5617
ISSN
2169-897X
Publisher
American Geophysical Union
Start Page
5607
End Page
5617
Journal / Book Title
Journal of Geophysical Research: Atmospheres
Volume
123
Issue
10
Copyright Statement
©2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
Sponsor
Commission of the European Communities
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000435445600048&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
682587
Subjects
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
peat
PM2
5
fire
emissions
TRANSFORM INFRARED-SPECTROSCOPY
AUSTRALIAN VEGETATION FIRES
PREMATURE MORTALITY
FIELD-MEASUREMENTS
AIR-POLLUTION
TRACE GASES
FOREST
CARBON
INDONESIA
DERIVATION
Publication Status
Published
Date Publish Online
2018-05-16