scholarly journals Top-Down Estimation of Particulate Matter Emissions from Extreme Tropical Peatland Fires Using Geostationary Satellite Fire Radiative Power Observations

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7075
Author(s):  
Daniel Fisher ◽  
Martin J. Wooster ◽  
Weidong Xu ◽  
Gareth Thomas ◽  
Puji Lestari
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
El Niño ◽  
El Nino ◽  
Top Down ◽  
Fire Emissions ◽  
Se Asia ◽  
Particulate Matter Emissions ◽  
Radiative Power ◽  
Fire Radiative Power

Extreme fires in the peatlands of South East (SE) Asia are arguably the world’s greatest biomass burning events, resulting in some of the worst ambient air pollution ever recorded (PM10 > 3000 µg·m−3). The worst of these fires coincide with El Niño related droughts, and include huge areas of smouldering combustion that can persist for months. However, areas of flaming surface vegetation combustion atop peat are also seen, and we show that the largest of these latter fires appear to be the most radiant and intensely smoke-emitting areas of combustion present in such extreme fire episodes. Fire emissions inventories and early warning of the air quality impacts of landscape fire are increasingly based on the fire radiative power (FRP) approach to fire emissions estimation, including for these SE Asia peatland fires. “Top-down” methods estimate total particulate matter emissions directly from FRP observations using so-called “smoke emission coefficients” [Ce; g·MJ−1], but currently no discrimination is made between fire types during such calculations. We show that for a subset of some of the most thermally radiant peatland fires seen during the 2015 El Niño, the most appropriate Ce is around a factor of three lower than currently assumed (~16.8 ± 1.6 g·MJ−1 vs. 52.4 g·MJ−1). Analysis indicates that this difference stems from these highly radiant fires containing areas of substantial flaming combustion, which changes the amount of particulate matter emitted per unit of observable fire radiative heat release in comparison to more smouldering dominated events. We also show that even a single one of these most radiant fires is responsible for almost 10% of the overall particulate matter released during the 2015 fire event, highlighting the importance of this fire type to overall emission totals. Discriminating these different fires types in ways demonstrated herein should thus ultimately improve the accuracy of SE Asian fire emissions estimates derived using the FRP approach, and the air quality modelling which they support.

scholarly journals Global top-down smoke aerosol emissions estimation using satellite fire radiative power measurements

2013 ◽  
Vol 13 (10) ◽  
pp. 27327-27386 ◽  
Author(s):  
C. Ichoku ◽  
L. Ellison
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Boreal Forest ◽  
Biomass Burning ◽  
Emission Factors ◽  
Top Down ◽  
Smoke Aerosol ◽  
Radiative Power ◽  
Aerosol Emissions ◽  
Fire Radiative Power

Abstract. Biomass burning occurs seasonally in most vegetated parts of the world, consuming large amounts of biomass fuel, generating intense heat energy, and emitting corresponding amounts of smoke plumes that comprise different species of aerosols and trace gases. Accurate estimates of these emissions are required as model inputs to evaluate and forecast smoke plume transport and impacts on air quality, human health, clouds, weather, radiation, and climate. Emissions estimates have long been based on bottom-up approaches that are not only complex, but also fraught with compounding uncertainties. Fortunately, a series of recent studies have revealed that both the rate of biomass consumption and the rate of emission of aerosol particulate matter (PM) by open biomass burning are directly proportional to the rate of release of fire radiative energy (FRE), which is fire radiative power (FRP) that is measurable from satellite. This direct relationship enables the determination of coefficients of emission (Ce), which can be used to convert FRP or FRE to smoke aerosol emissions in the same manner as emission factors (EFs) are used to convert burned biomass to emissions. We have leveraged this relationship to generate the first global 1° × 1° gridded Ce product for smoke aerosol or total particulate matter (TPM) emissions using coincident measurements of FRP and aerosol optical thickness (AOT) from the Moderate-resolution Imaging Spectro-radiometer (MODIS) sensors aboard the Terra and Aqua satellites. This new Fire Energetics and Emissions Research version 1.0 (FEER.v1) Ce product has now been released to the community and can be obtained from http://feer.gsfc.nasa.gov/, along with the corresponding 1-to-1 mapping of their quality assurance (QA) flags that will enable the Ce values to be filtered by quality for use in various applications. The regional averages of Ce values for different ecosystem types were found to be in the ranges of: 16–21 g MJ−1 for savanna and grasslands, 15–32 g MJ−1 for tropical forest, 9–12 g MJ−1 for North American boreal forest, about ~24 g MJ−1 for Russian boreal forest, and 18–26 g MJ−1 for Russian croplands and natural vegetation. The FEER.v1 Ce product was multiplied with FRP data to generate smoke TPM emissions, which were compared with equivalent emissions products from three existing inventories. The smoke TPM emissions results from FEER.v1 showed higher and more reasonable estimates than those of two other emissions inventories that are based on bottom up approaches and already reported in the literature to be too low, but portrayed an overall reasonable agreement with those of another inventory based on a hybrid method that includes the top-down approach, thereby suggesting that top-down approaches may hold better promise and need to be further developed to accelerate the reduction of uncertainty associated with fire emissions estimation in air-quality and climate research and applications. Based on analysis of data covering the period of 2004–2011, FEER.v1 results show that ~65–85 Tg yr−1 of TPM is emitted globally from open biomass burning, with a generally decreasing trend over this short time period. The FEER.v1 Ce product is the first global gridded product in the family of "emission factors", that is based essentially on satellite measurements, and requires only direct satellite FRP measurements of an actively burning fire anywhere to evaluate its emission rate in near real time, which is essential for operational activities, such as the monitoring and forecasting of smoke emission impacts on air quality.

scholarly journals Global top-down smoke-aerosol emissions estimation using satellite fire radiative power measurements

2014 ◽  
Vol 14 (13) ◽  
pp. 6643-6667 ◽  
Author(s):  
C. Ichoku ◽  
L. Ellison
Keyword(s):  
Particulate Matter ◽  
Top Down ◽  
Total Particulate Matter ◽  
Fire Emissions ◽  
Radiative Power ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Power Measurements ◽  
Aerosol Emissions ◽  
Fire Radiative Power

Abstract. Fire emissions estimates have long been based on bottom-up approaches that are not only complex, but also fraught with compounding uncertainties. We present the development of a global gridded (1° × 1°) emission coefficients (Ce) product for smoke total particulate matter (TPM) based on a top-down approach using coincident measurements of fire radiative power (FRP) and aerosol optical thickness (AOT) from the Moderate-resolution Imaging Spectro-radiometer (MODIS) sensors aboard the Terra and Aqua satellites. This new Fire Energetics and Emissions Research version 1.0 (FEER.v1) Ce product has now been released to the community and can be obtained from

scholarly journals Vertical distribution of aerosols over the Maritime Continent during El Nino

2017 ◽  
Author(s):  
Jason Blake Cohen ◽  
Daniel Hui Loong Ng ◽  
Alan Wei Lun Lim ◽  
Xin Rong Chua
Keyword(s):  
Vertical Distribution ◽  
El Niño ◽  
Radiative Forcing ◽  
El Nino ◽  
Small Scale ◽  
Fire Plume ◽  
Radiative Power ◽  
Fire Properties ◽  
The Impact ◽  
Fire Radiative Power

Abstract. The vertical distribution of aerosols over Southeast Asia, a critical factor of aerosol lifetime, and impact on radiative forcing and precipitation, is examined for the 2006 post El-Nino fire burning season. Additionally, through analysis of measurements and modeling, we have reconfirmed the hypothesis that fire radiative power is underestimated. Our results are significantly different from what others are using. The horizontally constrained Maritime Continent’s fire plume median height, using the maximum variance of satellite observed Aerosol Optical Depth as the spatial and temporal constraint, is found to be 2.17 ± 1.53 km during the 2006 El Nino season. This is 0.96 km higher than random sampling and all other past studies, with 62 % of particles in the free troposphere. The impact is that the aerosol lifetime will be significantly longer, and that the aerosols will disperse in a direction different from if they were in the boundary layer. Application of a simple plume rise model using measurements of fire properties underestimates the median plume height by 0.34 km and more in the bottom-half of the plume. The center of the plume can be reproduced when fire radiative power is increased by 20 % (range from 0 % to 100 %). However, to reduce the biases found, improvements are required in terms of measurements of fire properties when cloud covered, representation of small scale convection, and inclusion of aerosol direct and semi-direct effects. The results provide the unique aerosol signature of fire under El-Nino conditions.

scholarly journals Trends in eastern China agricultural fire emissions derived from a combination of geostationary (Himawari) and polar (VIIRS) orbiter fire radiative power products

2020 ◽  
Vol 20 (17) ◽  
pp. 10687-10705
Author(s):  
Tianran Zhang ◽  
Mark C. de Jong ◽  
Martin J. Wooster ◽  
Weidong Xu ◽  
Lili Wang
Keyword(s):  
Remote Sensing ◽  
Air Quality ◽  
Crop Residue ◽  
Eastern China ◽  
Fire Emissions ◽  
Crop Residue Burning ◽  
Radiative Power ◽  
Agricultural Burning ◽  
Emissions Inventories ◽  
Fire Radiative Power

Abstract. Open burning of agricultural crop residues is widespread across eastern China, and during certain post-harvest periods this activity is believed to significantly influence air quality. However, the exact contribution of crop residue burning to major air quality exceedances and air quality episodes has proven difficult to quantify. Whilst highly successful in many regions, in areas dominated by agricultural burning, MODIS-based (MODIS: Moderate Resolution Imaging Spectroradiometer) fire emissions inventories such as the Global Fire Assimilation System (GFAS) and Global Fire Emissions Database (GFED) are suspected of significantly underestimating the magnitude of biomass burning emissions due to the typically very small, but highly numerous, fires involved that are quite easily missed by coarser-spatial-resolution remote sensing observations. To address this issue, we use twice-daily fire radiative power (FRP) observations from the “small-fire-optimised” VIIRS-IM FRP product and combine them with fire diurnal cycle information taken from the geostationary Himawari-8 satellite. Using this we generate a unique high-spatio-temporal-resolution agricultural burning inventory for eastern China for the years 2012–2015, designed to fully take into account small fires well below the MODIS burned area or active fire detection limit, focusing on dry matter burned (DMB) and emissions of CO2, CO, PM2.5, and black carbon. We calculate DMB totals 100 % to 400 % higher than reported by the GFAS and GFED4.1s, and we quantify interesting spatial and temporal patterns previously un-noted. Wheat residue burning, primarily occurring in May–June, is responsible for more than half of the annual crop residue burning emissions of all species, whilst a secondary peak in autumn (September–October) is associated with rice and corn residue burning. We further identify a new winter (November–December) burning season, hypothesised to be caused by delays in burning driven by the stronger implementation of residue burning bans during the autumn post-harvest season. Whilst our emissions estimates are far higher than those of other satellite-based emissions inventories for the region, they are lower than estimates made using traditional “crop-yield-based approaches” (CYBAs) by a factor of between 2 and 5. We believe that this is at least in part caused by outdated and overly high burning ratios being used in the CYBA, leading to the overestimation of DMB. Therefore, we conclude that satellite remote sensing approaches which adequately detect the presence of agricultural fires are a far better approach to agricultural fire emission estimation.

scholarly journals Smoke radiocarbon measurements from Indonesian fires provide evidence for burning of millennia-aged peat

2018 ◽  
Vol 115 (49) ◽  
pp. 12419-12424 ◽  
Author(s):  
Elizabeth B. Wiggins ◽  
Claudia I. Czimczik ◽  
Guaciara M. Santos ◽  
Yang Chen ◽  
Xiaomei Xu ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
El Niño ◽  
El Nino ◽  
Agricultural Waste ◽  
Turnover Time ◽  
Carbonaceous Aerosol ◽  
Fire Season ◽  
Climate Mitigation ◽  
Waste Burning

In response to a strong El Niño, fires in Indonesia during September and October 2015 released a large amount of carbon dioxide and created a massive regional smoke cloud that severely degraded air quality in many urban centers across Southeast Asia. Although several lines of evidence indicate that peat burning was a dominant contributor to emissions in the region, El Niño-induced drought is also known to increase deforestation fires and agricultural waste burning in plantations. As a result, uncertainties remain with respect to partitioning emissions among different ecosystem and fire types. Here we measured the radiocarbon content (14C) of carbonaceous aerosol samples collected in Singapore from September 2014 through October 2015, with the aim of identifying the age and origin of fire-emitted fine particulate matter (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm). The Δ14C of fire-emitted aerosol was −76 ± 51‰, corresponding to a carbon pool of combusted organic matter with a mean turnover time of 800 ± 420 y. Our observations indicated that smoke plumes reaching Singapore originated primarily from peat burning (∼85%), and not from deforestation fires or waste burning. Atmospheric transport modeling confirmed that fires in Sumatra and Borneo were dominant contributors to elevated PM2.5 in Singapore during the fire season. The mean age of the carbonaceous aerosol, which predates the Industrial Revolution, highlights the importance of improving peatland fire management during future El Niño events for meeting climate mitigation and air quality commitments.

scholarly journals Vertical distribution of aerosols over the Maritime Continent during El Niño

2018 ◽  
Vol 18 (10) ◽  
pp. 7095-7108 ◽  
Author(s):  
Jason Blake Cohen ◽  
Daniel Hui Loong Ng ◽  
Alan Wei Lun Lim ◽  
Xin Rong Chua
Keyword(s):  
Vertical Distribution ◽  
El Niño ◽  
El Nino ◽  
Fire Season ◽  
Free Troposphere ◽  
Fire Plume ◽  
Radiative Power ◽  
Fire Properties ◽  
Aerosol Plume ◽  
Fire Radiative Power

Abstract. The vertical distribution of aerosols over Southeast Asia, a critical factor impacting aerosol lifetime, radiative forcing, and precipitation, is examined for the 2006 post El Niño fire burning season. Combining these measurements with remotely sensed land, fire, and meteorological measurements, and fire plume modeling, we have reconfirmed that fire radiative power (FRP) is underestimated over Southeast Asia by MODIS measurements. These results are derived using a significantly different approach from other previously attempted approaches found in the literature. The horizontally constrained Maritime Continent's fire plume median height, using the maximum variance of satellite observed aerosol optical depth as the spatial and temporal constraint, is found to be 2.04 ± 1.52 km during the entirety of the 2006 El Niño fire season, and 2.19±1.50 km for October 2006. This is 0.83 km (0.98 km) higher than random sampling and all other past studies. Additionally, it is determined that 61 (+6–10) % of the bottom of the smoke plume and 83 (+8–11) % of the median of the smoke plume is in the free troposphere during the October maximum; while 49 (+7–9) % and 75 (+12–12) % of the total aerosol plume and the median of the aerosol plume, are correspondingly found in the free troposphere during the entire fire season. This vastly different vertical distribution will have impacts on aerosol lifetime and dispersal. Application of a simple plume rise model using measurements of fire properties underestimates the median plume height by 0.26 km over the entire fire season and 0.34 km over the maximum fire period. It is noted that the model underestimation over the bottom portions of the plume are much larger. The center of the plume can be reproduced when fire radiative power is increased by 20 % (with other parts of the plume ranging from an increase of 0 to 60 % depending on the portion of the plume and the length of the fire season considered). However, to reduce the biases found, improvements including fire properties under cloudy conditions, representation of small-scale convection, and inclusion of aerosol direct and semi-direct effects are required.

scholarly journals Impact of the 2015 El Nino event on winter air quality in China

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Luyu Chang ◽  
Jianming Xu ◽  
Xuexi Tie ◽  
Jianbin Wu
Keyword(s):  
Air Quality ◽  
El Niño ◽  
El Nino ◽  
El Niño Event

scholarly journals Combining fire radiative power observations with the fire weather index improves the estimation of fire emissions

2017 ◽  
Author(s):  
Francesca Di Giuseppe ◽  
Samuel Rémy ◽  
Florian Pappenberger ◽  
Fredrik Wetterhall
Keyword(s):  
Biomass Burning ◽  
Atmospheric Composition ◽  
Composition Analysis ◽  
Fire Weather ◽  
Atmospheric Conditions ◽  
Weather Index ◽  
Fire Weather Index ◽  
Fire Emissions ◽  
Radiative Power ◽  
Fire Radiative Power

Abstract. The atmospheric composition analysis and forecast for the European Copernicus Atmosphere Monitoring Services (CAMS) relies on biomass burning fire emission estimates from the Global Fire Assimilation System (GFAS). GFAS converts fire radiative power (FRP) observations from MODIS satellites into smoke constituents. Missing observations are filled in using persistence where observed FRP from the previous day are progressed in time until a new observation is recorded. One of the consequences of this assumption is an overestimation of fire duration, which in turn translates into an overestimation of emissions from fires. In this study persistence is replaced by modelled predictions using the Canadian Fire Weather Index (FWI), which describes how atmospheric conditions affect the vegetation moisture content and ultimately fire duration. The skill in predicting emissions from biomass burning is improved with the new technique, which indicates that using an FWI-based model to infer emissions from FRP is better than persistence when observations are not available.

scholarly journals Impact of El Niño Southern Oscillation on the interannual variability of methane and tropospheric ozone

2019 ◽  
Author(s):  
Matthew J. Rowlinson ◽  
Alexandru Rap ◽  
Stephen R. Arnold ◽  
Richard J. Pope ◽  
Martyn P. Chipperfield ◽  
...  
Keyword(s):  
Growth Rate ◽  
Interannual Variability ◽  
Biomass Burning ◽  
El Niño ◽  
Atmospheric Transport ◽  
El Nino ◽  
Southern Oscillation ◽  
Fire Emissions ◽  
Tropospheric O3 ◽  
Global Mean

Abstract. The growth rate of global methane (CH4) concentrations has a strong interannual variability which is believed to be driven largely by fluctuations in CH4 emissions from wetlands and wildfires, as well as changes to the atmospheric sink. The El Niño Southern Oscillation (ENSO) is known to influence fire occurrence, wetland emission and atmospheric transport, but there are still important uncertainties associated with the exact mechanism and magnitude of this influence. Here we use a modelling approach to investigate how fires and meteorology control the interannual variability of global carbon monoxide (CO), CH4 and ozone (O3) concentrations, particularly during large El Niño events. Using a three-dimensional chemical transport model (TOMCAT) coupled to a sophisticated aerosol microphysics scheme (GLOMAP) we simulate changes to CO, hydroxyl radical (OH) and O3 for the period 1997–2014. We then use an offline radiative transfer model to quantify the impact of changes to atmospheric composition as a result of specific drivers. During the El Niño event of 1997–1998, there were increased emissions from biomass burning globally. As a result, global CO concentrations increased by more than 40 %. This resulted in decreased global mass-weighted tropospheric OH concentrations of up to 9 % and a resulting 4 % increase in the CH4 atmospheric lifetime. The change in CH4 lifetime led to a 7.5 ppb yr−1 increase in global mean CH4 growth rate in 1998. Therefore biomass burning emission of CO could account for 72 % of the total effect of fire emissions on CH4 growth rate in 1998. Our simulations indicate variations in fire emissions and meteorology associated with El Niño have opposing impacts on tropospheric O3 burden. El Niño-related atmospheric transport changes decrease global tropospheric O3 concentrations leading to a −0.03 Wm−2 change in O3 radiative effect (RE). However, enhanced fire emission of precursors such as nitrous oxides (NOx) and CO increase O3 RE by 0.03 Wm−2. While globally the two mechanisms nearly cancel out, causing only a small change in global mean O3 RE, the regional changes are large   up to −0.33 Wm−2 with potentially important consequences for atmospheric heating and dynamics.

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