scholarly journals Biomass burning fuel consumption dynamics in the (sub)tropics assessed from satellite

2016 ◽  
Author(s):  
N. Andela ◽  
G. R. van der Werf ◽  
J. W. Kaiser ◽  
T. T. van Leeuwen ◽  
M. J. Wooster ◽  
...  
Keyword(s):  
South America ◽  
Fuel Consumption ◽  
Spatial Patterns ◽  
Biomass Burning ◽  
Field Measurements ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Return Periods ◽  
In Fire ◽  
Consumption Dynamics

Abstract. Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, SubSaharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar orbiting MODerate-resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned area estimates. The fuel consumption estimates based on the geostationary and polar orbiting instruments showed good agreement in terms of spatial patterns, but absolute fuel consumption estimates remained more uncertain. Fuel consumption varies considerably in space and time, complicating the comparison of various approaches and using field measurements to constrain our results. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia having higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, both by affecting fuel build up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build up rates than equally productive grasslands in Africa, although this effect might have been partially driven by the presence of grazers in Africa. Finally, land management in the form of deforestation and agriculture also considerably affected fuel consumption regionally. We conclude that combining FRP and burned area estimates, calibrated against field measurements, is a promising approach in deriving quantitative estimates of fuel consumption. Satellite derived fuel consumption estimates may both challenge our current understanding of spatiotemporal fuel consumption dynamics and serve as reference datasets to improve biogeochemical modelling approaches. Future field studies especially designed to validate satellite-based products, or airborne remote sensing, may further improve confidence in the absolute fuel consumption estimates which are quickly becoming the weakest link in fire emissions estimates.

scholarly journals Biomass burning fuel consumption dynamics in the tropics and subtropics assessed from satellite

2016 ◽  
Vol 13 (12) ◽  
pp. 3717-3734 ◽  
Author(s):  
Niels Andela ◽  
Guido R. van der Werf ◽  
Johannes W. Kaiser ◽  
Thijs T. van Leeuwen ◽  
Martin J. Wooster ◽  
...  
Keyword(s):  
South America ◽  
Fuel Consumption ◽  
Spatial Patterns ◽  
Field Measurements ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Return Periods ◽  
Sub Saharan ◽  
In Fire ◽  
Consumption Dynamics

Abstract. Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, Sub-Saharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar-orbiting Moderate Resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned-area estimates. The fuel consumption estimates based on the geostationary and polar-orbiting instruments showed good agreement in terms of spatial patterns. We used field measurements of fuel consumption to constrain our results, but the large variation in fuel consumption in both space and time complicated this comparison and absolute fuel consumption estimates remained more uncertain. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia to have higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, by affecting both fuel build-up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build-up rates than equally productive grasslands in Africa, although this effect might have been partially driven by the presence of grazers in Africa or differences in landscape management. Finally, land management in the form of deforestation and agriculture also considerably affected fuel consumption regionally. We conclude that combining FRP and burned-area estimates, calibrated against field measurements, is a promising approach in deriving quantitative estimates of fuel consumption. Satellite-derived fuel consumption estimates may both challenge our current understanding of spatiotemporal fuel consumption dynamics and serve as reference datasets to improve biogeochemical modelling approaches. Future field studies especially designed to validate satellite-based products, or airborne remote sensing, may further improve confidence in the absolute fuel consumption estimates which are quickly becoming the weakest link in fire emission estimates.

scholarly journals Estimates of biomass burning emissions in tropical Asia based on satellite-derived data

2010 ◽  
Vol 10 (5) ◽  
pp. 2335-2351 ◽  
Author(s):  
D. Chang ◽  
Y. Song
Keyword(s):  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Crop Residue ◽  
Fire Season ◽  
Burned Area ◽  
Published Data ◽  
Tropical Asia ◽  
Fire Emissions ◽  
Burned Areas ◽  
In Fire

Abstract. Biomass burning in tropical Asia emits large amounts of trace gases and particulate matter into the atmosphere, which has significant implications for atmospheric chemistry and climatic change. In this study, emissions from open biomass burning over tropical Asia were evaluated during seven fire years from 2000 to 2006 (1 March 2000–31 February 2007). The size of the burned areas was estimated from newly published 1-km L3JRC and 500-m MODIS burned area products (MCD45A1). Available fuel loads and emission factors were assigned to each vegetation type in a GlobCover characterisation map, and fuel moisture content was taken into account when calculating combustion factors. Over the whole period, both burned areas and fire emissions showed clear spatial and seasonal variations. The size of the L3JRC burned areas ranged from 36 031 km2 in fire year 2005 to 52 303 km2 in 2001, and the MCD45A1 burned areas ranged from 54 790 km2 in fire year 2001 to 148 967 km2 in 2004. Comparisons of L3JRC and MCD45A1 burned areas using ground-based measurements and other satellite data were made in several major burning regions, and the results suggest that MCD45A1 generally performed better than L3JRC, although with a certain degree of underestimation in forest areas. The average annual L3JRC-based emissions were 123 (102–152), 12 (9–15), 1.0 (0.7–1.3), 1.9 (1.4–2.6), 0.11 (0.09–0.12), 0.89 (0.63–1.21), 0.043 (0.036–0.053), 0.021 (0.021–0.023), 0.41 (0.34–0.52), 3.4 (2.6–4.3), and 3.6 (2.8–4.7) Tg yr−1 for CO2, CO, CH4, NMHCs, NOx, NH3, SO2, BC, OC, PM2.5, and PM10, respectively, whereas MCD45A1-based emissions were 122 (108–144), 9.3 (7.7–11.7), 0.63 (0.46–0.86), 1.1 (0.8–1.6), 0.11 (0.10–0.13), 0.54 (0.38–0.76), 0.043 (0.038–0.051), 0.033 (0.032–0.037), 0.39 (0.34–0.47), 3.0 (2.6–3.7), and 3.3 (2.8–4.0) Tg yr−1. Forest burning was identified as the major source of the fire emissions due to its high carbon density. Although agricultural burning was the second highest contributor, it is possible that some crop residue combustion was missed by satellite observations. This possibility is supported by comparisons with previously published data, and this result may be due to the small size of the field crop residue burning. Fire emissions were mainly concentrated in Indonesia, India, Myanmar, and Cambodia. Furthermore, the peak in the size of the burned area was generally found in the early fire season, whereas the maximum fire emissions often occurred in the late fire season.

scholarly journals OMI observations of the anomalous 2008 Southern Hemisphere biomass burning season

2009 ◽  
Vol 9 (5) ◽  
pp. 21509-21524 ◽  
Author(s):  
O. Torres ◽  
Z. Chen ◽  
H. Jethva ◽  
C. Ahn ◽  
S. R. Freitas ◽  
...  
Keyword(s):  
South America ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Fire Season ◽  
Aerosol Layer ◽  
Carbonaceous Aerosols ◽  
Synoptic Scale ◽  
Ozone Monitoring Instrument ◽  
Smoke Layer ◽  
In Fire

Abstract. The 2008 season of biomass burning in the Southern Hemisphere was marked by a significant reduction in the number of fires in South America and, therefore, a large drop of the atmospheric load of carbonaceous aerosols over the subcontinent, relative to previous years, was registered by the Ozone Monitoring Instrument onboard the Aura satellite. In contrast, the 2008 copious aerosol production by fires in Central and Southern Africa generated an unusually large, synoptic scale aerosol layer that blanketed most of the tropical Southern Atlantic Ocean (0°–25° S) in August and September. Satellite observations on fire statistics and precipitation were analyzed to understand the anomalous Southern Hemisphere fire season. The fire reduction in South America was confined to Brazil that experienced a 62% reduction in fire activity in relation to 2007, and it was the result of factors other than meteorological reasons. The large spatial extent of the South Atlantic smoke layer seem to have been the result of unusually high free troposphere easterly winds that efficiently mobilized particulate matter thousands of kilometers away from the African source areas.

scholarly journals OMI and MODIS observations of the anomalous 2008–2009 Southern Hemisphere biomass burning seasons

2010 ◽  
Vol 10 (8) ◽  
pp. 3505-3513 ◽  
Author(s):  
O. Torres ◽  
Z. Chen ◽  
H. Jethva ◽  
C. Ahn ◽  
S. R. Freitas ◽  
...  
Keyword(s):  
South America ◽  
Biomass Burning ◽  
Atmospheric Aerosol ◽  
Meteorological Factor ◽  
Precipitation Anomaly ◽  
Fire Season ◽  
Carbonaceous Aerosols ◽  
Precipitation Record ◽  
Fire Activity ◽  
In Fire

Abstract. Significant inter-annual variability of biomass burning was observed in South America over the 2007–2009 period. The 2007 number of fires detected from space in South America, as well as the magnitude of the atmospheric aerosol load resulting from fire activity, was the largest over the last ten years. The huge 2007 increase in fire activity was followed by large reductions in the 2008 and 2009 burning seasons. Large drops of the atmospheric load of carbonaceous aerosols over the subcontinent, relative to previous years, was registered in 2008 and 2009 by the OMI sensor onboard the Aura platform, and the MODIS sensors on the Terra and Aqua satellites. The 2009 fire season in South America was the least active of the last ten years. Satellite observations of fire statistics, precipitation, and aerosol optical depth data were used to analyze the fire season over South America and Central Africa during the last ten years to understand the factors that led to the 2007 and 2009 extremes. An analysis of precipitation anomaly data shows that the largest 6-month (May–October) precipitation deficit of the last ten years in South America occurred during 2007. The same analysis indicates that in 2009, this region experienced the largest excess precipitation of the decade. Since precipitation is the most important meteorological factor controlling biomass burning activity, it can be concluded that the 2007 maximum and 2009 minimum in fire activity and aerosol load were driven by the observed levels of precipitation. Analysis of the precipitation record, however, does not explain the extremely low 2008 biomass burning activity. Although the 2008 precipitation deficit was similar in magnitude to the one that in 2005 contributed to the second most intense biomass burning season in the last ten years, the 2008 fire season was surprisingly weak. The combined analysis of satellite data on atmospheric aerosol load, fire counts and precipitation strongly suggests that the observed 2008 decline in aerosol load and fire activity in South America was heavily influenced by conditions other than meteorological factors.

scholarly journals Estimates of biomass burning emissions in tropical Asia based on satellite-derived data

2009 ◽  
Vol 9 (5) ◽  
pp. 19599-19640 ◽  
Author(s):  
D. Chang ◽  
Y. Song
Keyword(s):  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Vegetation Type ◽  
Burned Area ◽  
Tropical Asia ◽  
Fire Emissions ◽  
Burned Areas ◽  
Fuel Moisture Content ◽  
In Fire ◽  
Derived Data

Abstract. Biomass burning in tropical Asia emits large amounts of trace gases and particulate matters into the atmosphere, which has significant implications for atmospheric chemistry and climatic change. In this study, emissions from open biomass burning over tropical Asia were evaluated during seven fire years from 2000–2006 (1 April 2000–31 March 2007). Burned areas were estimated from newly published 1-km L3JRC and 500-m MODIS burned area products (MCD45A1). Available fuel loads and emission factors were assigned for each vegetation type in a GlobCover characterisation map, and fuel moisture content was taken into account when calculating combustion factors. Over the whole period, both burned areas and fire emissions clearly showed spatial and seasonal variations. The L3JRC burned areas ranged from 31 165 km2 in fire year 2005 to 57 313 km2 in 2000, while the MCD45A1 burned areas ranged from 54 260 km2 in fire year 2001 to 127 068 km2 in 2004. Comparisons of L3JRC and MCD45A1 burned areas with ground-based measurements and other satellite information were constructed in several major burning regions, and results suggested that MCD45A1 performed better in most areas than L3JRC did although with a certain degree of underestimation of burned forest areas. The average annual L3JRC-based emissions were 125, 12, 0.98, 1.91, 0.11, 0.89, 0.044, 0.022, 0.42, 3.40, and 3.68 Tg yr

scholarly journals Reductions in NO2 burden over north equatorial Africa from decline in biomass burning in spite of growing fossil fuel use, 2005 to 2017

2021 ◽  
Vol 118 (7) ◽  
pp. e2002579118
Author(s):  
Jonathan E. Hickman ◽  
Niels Andela ◽  
Kostas Tsigaridis ◽  
Corinne Galy-Lacaux ◽  
Money Ossohou ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Socioeconomic Development ◽  
Fossil Fuel ◽  
Dry Season ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Fuel Use ◽  
Middle Income ◽  
Equatorial Africa ◽  
Low And Middle Income

Socioeconomic development in low- and middle-income countries has been accompanied by increased emissions of air pollutants, such as nitrogen oxides [NOx: nitrogen dioxide (NO2) + nitric oxide (NO)], which affect human health. In sub-Saharan Africa, fossil fuel combustion has nearly doubled since 2000. At the same time, landscape biomass burning—another important NOx source—has declined in north equatorial Africa, attributed to changes in climate and anthropogenic fire management. Here, we use satellite observations of tropospheric NO2 vertical column densities (VCDs) and burned area to identify NO2 trends and drivers over Africa. Across the northern ecosystems where biomass burning occurs—home to hundreds of millions of people—mean annual tropospheric NO2 VCDs decreased by 4.5% from 2005 through 2017 during the dry season of November through February. Reductions in burned area explained the majority of variation in NO2 VCDs, though changes in fossil fuel emissions also explained some variation. Over Africa’s biomass burning regions, raising mean GDP density (USD⋅km−2) above its lowest levels is associated with lower NO2 VCDs during the dry season, suggesting that economic development mitigates net NO2 emissions during these highly polluted months. In contrast to the traditional notion that socioeconomic development increases air pollutant concentrations in low- and middle-income nations, our results suggest that countries in Africa’s northern biomass-burning region are following a different pathway during the fire season, resulting in potential air quality benefits. However, these benefits may be lost with increasing fossil fuel use and are absent during the rainy season.

scholarly journals Controls on fire activity over the Holocene

2015 ◽  
Vol 11 (5) ◽  
pp. 781-788 ◽  
Author(s):  
S. Kloster ◽  
T. Brücher ◽  
V. Brovkin ◽  
S. Wilkenskjeld
Keyword(s):  
Global Scale ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Fuel Moisture ◽  
Climate Control ◽  
The Holocene ◽  
Continental Scale ◽  
Fire Activity ◽  
Sub Saharan ◽  
In Fire

Abstract. Changes in fire activity over the last 8000 years are simulated with a global fire model driven by changes in climate and vegetation cover. The changes were separated into those caused through variations in fuel availability, fuel moisture or wind speed, which react differently to changes in climate. Disentangling these controlling factors helps in understanding the overall climate control on fire activity over the Holocene. Globally the burned area is simulated to increase by 2.5% between 8000 and 200 cal yr BP, with larger regional changes compensating nearly evening out on a global scale. Despite the absence of anthropogenic fire ignitions, the simulated trends in fire activity agree reasonably well with continental-scale reconstructions from charcoal records, with the exception of Europe. For some regions the change in fire activity is predominantly controlled through changes in fuel availability (Australia monsoon, Central America tropics/subtropics). For other regions changes in fuel moisture are more important for the overall trend in fire activity (North America, Sub-Saharan Africa, Europe, Asia monsoon). In Sub-Saharan Africa, for example, changes in fuel moisture alone lead to an increase in fire activity between 8000 and 200 cal yr BP, while changes in fuel availability lead to a decrease. Overall, the fuel moisture control is dominating the simulated fire activity for Sub-Saharan Africa. The simulations clearly demonstrate that both changes in fuel availability and changes in fuel moisture are important drivers for the fire activity over the Holocene. Fuel availability and fuel moisture do, however, have different climate controls. As such, observed changes in fire activity cannot be related to single climate parameters such as precipitation or temperature alone. Fire models, as applied in this study, in combination with observational records can help in understanding the climate control on fire activity, which is essential to project future fire activity.

Biomass burning decline causes large reductions in NO2 burden over north equatorial Africa in spite of growing fossil fuel use

2020 ◽  
Author(s):  
Jonathan Hickman ◽  
Niels Andela ◽  
Money Ossohou ◽  
Corinne Galy-Lacaux ◽  
Kostas Tsigaridis ◽  
...  
Keyword(s):  
Economic Development ◽  
Air Quality ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Fuel Use ◽  
Middle Income ◽  
Socio Economic Development ◽  
Low And Middle Income

<p>Socio-economic development in low and middle-income countries has been accompanied by increased emissions of air pollutants such as nitrogen oxides (NO<sub>x</sub>: nitrogen dioxide (NO<sub>2</sub>) + nitric oxide (NO)), which affect human health.  In sub-Saharan Africa, fossil fuel combustion has nearly doubled since 2000.  At the same time, biomass burning—another important NO<sub>x</sub> source—has declined in Africa’s northern biomass burning region, attributed to changes in climate and anthropogenic fire management associated with agricultural development. Here we use satellite observations of tropospheric NO<sub>2</sub> vertical column densities (VCDs) and burned area to identify NO<sub>2</sub> trends and drivers over Africa. Across the northern ecosystems where biomass burning occurs—home to over 350 million people—mean annual tropospheric NO<sub>2 </sub>VCDs decreased by 4.5% from 2005 through 2017 during the biomass burning season of November through February. Reductions in burned area explained the majority of these change in NO<sub>2</sub> VCDs, but there were also weaker relationships between changes in NO<sub>2</sub> VCDs and fossil fuel emissions over parts of West Africa, which were stronger during rainy season. Over Africa’s biomass burning regions, NO<sub>2</sub> VCDs tended to decrease with increasing population density up to a threshold of approximately 180 people per km<sup>2</sup>, suggesting that anthropogenic activity causes a net reduction in NO<sub>2</sub> emissions across roughly 90% of the continent’s biomass burning regions. In contrast to the widely-held perception that socio-economic development worsens air quality in low and middle-income nations, our results suggest that countries in Africa’s northern biomass burning region are following a different pathway, resulting in regional air quality benefits. However, these benefits may be lost with increasing fossil fuel use.</p>

scholarly journals Controls on fire activity over the Holocene

2014 ◽  
Vol 10 (6) ◽  
pp. 4257-4275
Author(s):  
S. Kloster ◽  
T. Brücher ◽  
V. Brovkin ◽  
S. Wilkenskjeld
Keyword(s):  
Global Scale ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Fuel Moisture ◽  
Climate Control ◽  
The Holocene ◽  
Continental Scale ◽  
Fire Activity ◽  
Sub Saharan ◽  
In Fire

Abstract. Changes in fire activity over the last 8000 years are simulated with a global fire model driven by changes in climate and vegetation cover. The changes were separated into those caused through variations in fuel availability, fuel moisture or wind speed which react differently to changes in climate. Disentangling these controlling factors helps to understand the overall climate control on fire activity over the Holocene. Globally the burned area is simulated to increase by 2.5% between 8000 and 200 cal yr BP with larger regional changes compensating on a global scale. Despite the absence of anthropogenic fire ignitions, the simulated trends in fire activity agree reasonably well with continental scale reconstructions from charcoal records, with the exception of Europe. For some regions the change in fire activity is predominantly controlled through changes in fuel availability (Australia-Monsoon, American Tropics/Subtropics). For other regions changes in fuel moisture are more important for the overall trend in fire activity (North America, Sub-Saharan Africa, Europe, Asia-Monsoon). In Sub-Saharan Africa, for example, changes in fuel moisture alone lead to an increase in fire activity between 8000 and 200 cal yr BP, while changes in fuel availability lead to a decrease. Overall, the fuel moisture control is dominating the simulated fire activity for Sub-Saharan Africa. The simulations clearly demonstrate that both changes in fuel availability and changes in fuel moisture are important drivers for the fire activity over the Holocene. Fuel availability and fuel moisture do, however, have different climate controls. As such observed changes in fire activity can not be related to single climate parameters such as precipitation or temperature alone. Fire models, as applied in this study, in combination with observational records can help to understand the climate control on fire activity, which is essential to project future fire activity.

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