scholarly journals Daily burned area and carbon emissions from boreal fires in Alaska

2014 ◽  
Vol 11 (12) ◽  
pp. 17579-17629
Author(s):  
S. Veraverbeke ◽  
B. M. Rogers ◽  
J. T. Randerson

Abstract. Boreal fires burn carbon-rich organic soils, thereby releasing large quantities of trace gases and aerosols that influence atmospheric composition and climate. To better understand the factors regulating boreal fire emissions, we developed a statistical model of carbon consumption by fire for Alaska with a spatial resolution of 500 m and a temporal resolution of one day. We used the model to estimate variability in carbon emissions between 2001 and 2012. Daily burned area was mapped using imagery from the Moderate Resolution Imaging Spectroradiometer combined with perimeters from the Alaska Large Fire Database. Carbon consumption was calibrated using available field measurements from black spruce forests in Alaska. We built two nonlinear multiplicative models to separately predict above- and belowground carbon consumption by fire in response to environmental variables including elevation, day of burning within the fire season, pre-fire tree cover and the differenced normalized burn ratio (dNBR). Higher belowground consumption occurred later in the season and for mid-elevation regions. Aboveground and belowground consumption also increased as a function of tree cover and the dNBR, suggesting a causal link between the processes regulating these two components of consumption. Between 2001 and 2012, the median fuel consumption was 2.48 kg C m-2 and the median pixel-based uncertainty (SD of prediction error) was 0.38 kg C m-2. There were considerable amounts of burning in other cover types than black spruce and consumption in pure black spruce stands was generally higher. Fuel consumption originated primarily from the belowground fraction (median = 2.30 kg C m-2 for all cover types and 2.63 kg C m-2 for pure black spruce stands). Total carbon emissions varied considerably from year to year, with the highest emissions occurring during 2004 (67 Tg C), 2005 (44 Tg C), 2009 (25 Tg C), and 2002 (16 Tg C) and a mean of 14 Tg C per year between 2001 and 2012. Our analysis highlights the importance of accounting for the spatial heterogeneity within fuels and consumption when extrapolating emissions in space and time. This data on daily burned area and emissions may be useful for in understanding controls and limits on fire growth, and predicting potential feedbacks of changing fire regimes.

2015 ◽  
Vol 12 (11) ◽  
pp. 3579-3601 ◽  
Author(s):  
S. Veraverbeke ◽  
B. M. Rogers ◽  
J. T. Randerson

Abstract. Boreal fires burn into carbon-rich organic soils, thereby releasing large quantities of trace gases and aerosols that influence atmospheric composition and climate. To better understand the factors regulating boreal fire emissions, we developed a statistical model of carbon consumption by fire for Alaska with a spatial resolution of 450 m and a temporal resolution of 1 day. We used the model to estimate variability in carbon emissions between 2001 and 2012. Daily burned area was mapped using imagery from the Moderate Resolution Imaging Spectroradiometer combined with perimeters from the Alaska Large Fire Database. Carbon consumption was calibrated using available field measurements from black spruce forests in Alaska. We built two nonlinear multiplicative models to separately predict above- and belowground carbon consumption by fire in response to environmental variables including elevation, day of burning within the fire season, pre-fire tree cover and the differenced normalized burn ratio (dNBR). Higher belowground carbon consumption occurred later in the season and for mid-elevation forests. Topographic slope and aspect did not improve performance of the belowground carbon consumption model. Aboveground and belowground carbon consumption also increased as a function of tree cover and the dNBR, suggesting a causal link between the processes regulating these two components of carbon consumption. Between 2001 and 2012, the median carbon consumption was 2.54 kg C m-2. Burning in land-cover types other than black spruce was considerable and was associated with lower levels of carbon consumption than for pure black spruce stands. Carbon consumption originated primarily from the belowground fraction (median = 2.32 kg C m-2 for all cover types and 2.67 kg C m-2 for pure black spruce stands). Total carbon emissions varied considerably from year to year, with the highest emissions occurring during 2004 (69 Tg C), 2005 (46 Tg C), 2009 (26 Tg C), and 2002 (17 Tg C) and a mean of 15 Tg C year-1 between 2001 and 2012. Mean uncertainty of carbon consumption for the domain, expressed as 1 standard deviation (SD), was 0.50 kg C m-2. Uncertainties in the multiplicative regression model used to estimate belowground consumption in black spruce stands and the land-cover classification were primary contributors to uncertainty estimates. Our analysis highlights the importance of accounting for the spatial heterogeneity of fuels and combustion when extrapolating emissions in space and time, and the need for of additional field campaigns to increase the density of observations as a function of tree cover and other environmental variables influencing consumption. The daily emissions time series from the Alaskan Fire Emissions Database (AKFED) presented here creates new opportunities to study environmental controls on daily fire dynamics, optimize boreal fire emissions in biogeochemical models, and quantify potential feedbacks from changing fire regimes.


2017 ◽  
Author(s):  
Guido R. van der Werf ◽  
James T. Randerson ◽  
Louis Giglio ◽  
Thijs T. van Leeuwen ◽  
Yang Chen ◽  
...  

Abstract. Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long term fire records are needed that fuse information from different satellite and in-situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997–2015. The modeling system, based on the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include: 1) new burned area estimates with contributions from small fires, 2) a revised fuel consumption parameterization optimized using field observations, 3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and 4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25°) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.2 x 1015 grams carbon per year (Pg C yr-1) during 1997–2015, with a maximum in 1997 (3.0 Pg C yr-1) and minimum in 2013 (1.8 Pg C yr-1). These estimates were 11 % higher than our previous estimates (GFED3) during 1997–2011, when the two datasets overlapped. This increase was the result of a substantial increase in burned area (37 %), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (–19 %) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the "s" for small fires), average emissions were 1.5 Pg C yr-1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. Our improved dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth System. GFED data is available from http://www.globalfiredata.org.


2006 ◽  
Vol 6 (2) ◽  
pp. 3175-3226 ◽  
Author(s):  
G. R. van der Werf ◽  
J. T. Randerson ◽  
L. Giglio ◽  
G. J. Collatz ◽  
P. S. Kasibhatla ◽  
...  

Abstract. Biomass burning represents an important source of atmospheric aerosols and greenhouse gases, yet little is known about its interannual variability or the underlying mechanisms regulating this variability at continental to global scales. Here we investigated fire emissions during the 8 year period from 1997 to 2004 using satellite data and the CASA biogeochemical model. Burned area from 2001–2004 was derived using newly available active fire and 500 m burned area datasets from MODIS following the approach described by Giglio et al. (2005). ATSR and VIRS satellite data were used to extend the burned area time series back in time through 1997. In our analysis we estimated fuel loads, including peatland fuels, and the net flux from terrestrial ecosystems as the balance between net primary production (NPP), heterotrophic respiration (Rh), and biomass burning, using time varying inputs of precipitation (PPT), temperature, solar radiation, and satellite-derived fractional absorbed photosynthetically active radiation (fAPAR). For the 1997–2004 period, we found that on average approximately 58 Pg C year−1 was fixed by plants, and approximately 95% of this was returned back to the atmosphere via Rh. Another 4%, or 2.5 Pg C year−1 was emitted by biomass burning; the remainder consisted of losses from fuel wood collection and subsequent burning. At a global scale, burned area and total fire emissions were largely decoupled from year to year. Total carbon emissions tracked burning in forested areas (including deforestation fires in the tropics), whereas burned area was largely controlled by savanna fires that responded to different environmental and human factors. Biomass burning emissions showed large interannual variability with a range of more than 1 Pg C year−1, with a maximum in 1998 (3.2 Pg C year−1) and a minimum in 2000 (2.0 Pg C year−1).


2017 ◽  
Vol 9 (2) ◽  
pp. 697-720 ◽  
Author(s):  
Guido R. van der Werf ◽  
James T. Randerson ◽  
Louis Giglio ◽  
Thijs T. van Leeuwen ◽  
Yang Chen ◽  
...  

Abstract. Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997–2016. The modeling system, based on the Carnegie–Ames–Stanford Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include (1) new burned area estimates with contributions from small fires, (2) a revised fuel consumption parameterization optimized using field observations, (3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and (4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25°) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.2  ×  1015 grams of carbon per year (Pg C yr−1) during 1997–2016, with a maximum in 1997 (3.0 Pg C yr−1) and minimum in 2013 (1.8 Pg C yr−1). These estimates were 11 % higher than our previous estimates (GFED3) during 1997–2011, when the two datasets overlapped. This net increase was the result of a substantial increase in burned area (37 %), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (−19 %) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the s for small fires), average emissions were 1.5 Pg C yr−1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. This small fire layer carries substantial uncertainties; improving these estimates will require use of new burned area products derived from high-resolution satellite imagery. Our revised dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth system. GFED data are available from http://www.globalfiredata.org.


2014 ◽  
Vol 18 (16) ◽  
pp. 1-26 ◽  
Author(s):  
Nancy H. F. French ◽  
Donald McKenzie ◽  
Tyler Erickson ◽  
Benjamin Koziol ◽  
Michael Billmire ◽  
...  

Abstract As carbon modeling tools become more comprehensive, spatial data are needed to improve quantitative maps of carbon emissions from fire. The Wildland Fire Emissions Information System (WFEIS) provides mapped estimates of carbon emissions from historical forest fires in the United States through a web browser. WFEIS improves access to data and provides a consistent approach to estimating emissions at landscape, regional, and continental scales. The system taps into data and tools developed by the U.S. Forest Service to describe fuels, fuel loadings, and fuel consumption and merges information from the U.S. Geological Survey (USGS) and National Aeronautics and Space Administration on fire location and timing. Currently, WFEIS provides web access to Moderate Resolution Imaging Spectroradiometer (MODIS) burned area for North America and U.S. fire-perimeter maps from the Monitoring Trends in Burn Severity products from the USGS, overlays them on 1-km fuel maps for the United States, and calculates fuel consumption and emissions with an open-source version of the Consume model. Mapped fuel moisture is derived from daily meteorological data from remote automated weather stations. In addition to tabular output results, WFEIS produces multiple vector and raster formats. This paper provides an overview of the WFEIS system, including the web-based system functionality and datasets used for emissions estimates. WFEIS operates on the web and is built using open-source software components that work with open international standards such as keyhole markup language (KML). Examples of emissions outputs from WFEIS are presented showing that the system provides results that vary widely across the many ecosystems of North America and are consistent with previous emissions modeling estimates and products.


2021 ◽  
Vol 118 (9) ◽  
pp. e2011160118
Author(s):  
Ruben Ramo ◽  
Ekhi Roteta ◽  
Ioannis Bistinas ◽  
Dave van Wees ◽  
Aitor Bastarrika ◽  
...  

Fires are a major contributor to atmospheric budgets of greenhouse gases and aerosols, affect soils and vegetation properties, and are a key driver of land use change. Since the 1990s, global burned area (BA) estimates based on satellite observations have provided critical insights into patterns and trends of fire occurrence. However, these global BA products are based on coarse spatial-resolution sensors, which are unsuitable for detecting small fires that burn only a fraction of a satellite pixel. We estimated the relevance of those small fires by comparing a BA product generated from Sentinel-2 MSI (Multispectral Instrument) images (20-m spatial resolution) with a widely used global BA product based on Moderate Resolution Imaging Spectroradiometer (MODIS) images (500 m) focusing on sub-Saharan Africa. For the year 2016, we detected 80% more BA with Sentinel-2 images than with the MODIS product. This difference was predominately related to small fires: we observed that 2.02 Mkm2 (out of a total of 4.89 Mkm2) was burned by fires smaller than 100 ha, whereas the MODIS product only detected 0.13 million km2 BA in that fire-size class. This increase in BA subsequently resulted in increased estimates of fire emissions; we computed 31 to 101% more fire carbon emissions than current estimates based on MODIS products. We conclude that small fires are a critical driver of BA in sub-Saharan Africa and that including those small fires in emission estimates raises the contribution of biomass burning to global burdens of (greenhouse) gases and aerosols.


2021 ◽  
Vol 4 (1) ◽  
pp. 42-49
Author(s):  
Anukram Sharma ◽  
Khem N Poudyal ◽  
Nawraj Bhattarai

Study of carbon footprint is an emerging field which provides statistical analysis about the contribution of an activity on global climate change. Every human activity in daily life is achieved at the expense of those substances which directly or indirectly contribute to global warming. In this era of global communication, humans are habitual to know about the ongoing changes in the world. Newspapers are one of the reliable sources for getting updated about the global information. Paper-based newspapers come at the cost of greenhouse gas emissions. So, this article based upon an analysis of carbon footprint of Nepal’s national daily newspaper provides evaluation of each of the following: carbon emission during the manufacturing of raw materials, carbon emission from fuel consumption during transportation of raw materials, carbon emissions during the printing of newspaper and carbon emission from the fuel consumption during the transportation of printed newspaper. During the study period of 2019 A.D., the result shows that the total carbon emission of Gorkhapatra newspaper was found to be 2308.5 kg CO2e per ton. The upshot of this study provides not only thorough information about carbon emissions but also builds a foundation for calculation of carbon emissions from paper used in various sectors.


2001 ◽  
Vol 31 (3) ◽  
pp. 512-525 ◽  
Author(s):  
B D Amiro ◽  
J B Todd ◽  
B M Wotton ◽  
K A Logan ◽  
M D Flannigan ◽  
...  

Direct emissions of carbon from Canadian forest fires were estimated for all Canada and for each ecozone for the period 1959–1999. The estimates were based on a data base of large fires for the country and calculations of fuel consumption for each fire using the Canadian Forest Fire Behaviour Prediction System. This technique used the fire locations and start dates to estimate prevailing fire weather and fuel type for each of about 11 000 fires. An average of 2 × 106 ha·year–1 was burned in this period, varying from 0.3 × 106 ha in 1978 to 7.5 × 106 ha in 1989. Ecozones of the boreal and taiga areas experienced the greatest area burned, releasing most of the carbon (C). The mean area-weighted fuel consumption for all fires was 2.6 kg dry fuel·m–2 (1.3 kg C·m–2), but ecozones vary from 1.8 to 3.9 kg dry fuel·m–2. The mean annual estimate of direct carbon emissions was 27 ± 6 Tg C·year–1. Individual years ranged from 3 to 115 Tg C·year–1. These direct fire emissions represent about 18% of the current carbon dioxide emissions from the Canadian energy sector, on average, but vary from 2 to 75% among years. Post-fire effects cause an additional loss of carbon and changes to the forest sink condition.


2020 ◽  
Author(s):  
Valentina Bacciu ◽  
Carla Scarpa ◽  
Costantino Sirca ◽  
Spano Donatella

<p>Vegetation fires contribute to 38% to the emission of CO<sub>2</sub> into the atmosphere, against 62% caused by the combustion of fossil fuels. Further, it could approach levels of anthropogenic carbon emissions, especially in years of extreme fire activity (e.g. 2003, 2017). According to the equation first proposed by Seiler and Crutzen (1980), fire emission estimation use information on the amount of burned biomass, the emission factors associated with each specific chemical species, the burned area, and the combustion efficiency. Still, simulating emission from forest fires is affected by several errors and uncertainties, due to the different assessment approach to characterize the various parameters involved in the equation. For example, regional assessment relied on fire-activity reports from forest services, with assumptions regarding the type of vegetation burned, the characteristics of burning, and the burned area. Improvements and new advances in remote sensing, experimental measurements of emission factors, fuel consumption models, fuel load evaluation, and spatial and temporal distribution of burning are a valuable help for predicting and quantifying accurately the source and the composition of fire emissions.</p><p>With the aim to contribute to a better estimation of biomass burning emission, in this work we compared fire emission estimations using two different types of burned area products and combustion efficiency approaches in the framework of the recently developed system for modeling fire emission in Italy (Bacciu et al., 2012). This methodology combines a fire emission model (FOFEM - First Order Fire Effect Model, Reinhardt et al., 1997) with spatial and non-spatial inputs related to fire, vegetation, and weather conditions. The perimeters and burned area of selected large fires that occurred in 2017 in Italy were obtained by the former Corpo Forestale dello Stato (actually Carabinieri C.U.F.A.A.) and by the Copernicus Emergency Management Service (EMS). The vegetation types were derived from CORINE LAND COVER (2012). For each vegetation type, fuel loading was assigned using a combination of field observations and literature data (e.g., Mitsopoulos and Dimitrakopoulos 2007; Ascoli et al., 2019). Fuel moisture conditions, influencing the combustion efficiency, were derived from the daily Canadian Fine Fuels Moisture Code (FFMC), calculated from MARS interpolated weather data (25km x 25km). The daily FFMC was then associated with the two types of fire data with the aim of group fires in function of their relative ease of ignition and flammability of fine fuel (burning conditions, from low to extreme). For the EMS fire, it was also possible to further define fire severity and thus the percentage of combusted crown through the assessed fire damage grade.</p><p>The results showed differences in the total emissions according to the fire product and the approach to estimate the combustion efficiency. Furthermore, it seems that the difference in the evaluation of severity - and therefore in the degree of combustion of the canopy- affects more than the differences in terms of area burned. Overall, the results pointed out the crucial role of appropriate fuel, fire, and weather data and maps to attain reasonable simulations of fuel consumption and smoke emissions.</p>


2007 ◽  
Vol 16 (5) ◽  
pp. 593 ◽  
Author(s):  
William J. de Groot ◽  
Robert Landry ◽  
Werner A. Kurz ◽  
Kerry R. Anderson ◽  
Peter Englefield ◽  
...  

In support of Canada’s National Forest Carbon Monitoring, Accounting and Reporting System, a project was initiated to develop and test procedures for estimating direct carbon emissions from fires. The Canadian Wildland Fire Information System (CWFIS) provides the infrastructure for these procedures. Area burned and daily fire spread estimates are derived from satellite products. Spatially and temporally explicit indices of burning conditions for each fire are calculated by CWFIS using fire weather data. The Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) provides detailed forest type and leading species information, as well as pre-fire fuel load data. The Boreal Fire Effects Model calculates fuel consumption for different live biomass and dead organic matter pools in each burned cell according to fuel type, fuel load, burning conditions, and resulting fire behaviour. Carbon emissions are calculated from fuel consumption. CWFIS summarises the data in the form of disturbance matrices and provides spatially explicit estimates of area burned for national reporting. CBM-CFS3 integrates, at the national scale, these fire data with data on forest management and other disturbances. The methodology for estimating fire emissions was tested using a large-fire pilot study. A framework to implement the procedures at the national scale is described.


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