scholarly journals Fire emission rates of NO<sub>x</sub> based on the empirical relationship between satellite-derived tropospheric NO<sub>2</sub> and fire radiative power

2013 ◽  
Vol 13 (11) ◽  
pp. 28453-28510
Author(s):  
S. F. Schreier ◽  
A. Richter ◽  
J. W. Kaiser ◽  
J. P. Burrows
Keyword(s):  
Atmospheric Chemistry ◽  
Empirical Relationship ◽  
Temporal Correlation ◽  
Fire Intensity ◽  
Burned Area ◽  
Emission Rates ◽  
Monthly Means ◽  
Radiative Power ◽  
The Tropics ◽  
Fire Radiative Power

Abstract. Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area on average globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from GFEDv3.1 over 5 characteristic biomass burning regions in the tropics and subtropics indicated good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28–1.03 g NOx s−1 MW−1) and highest for croplands and woody savannas (0.82–1.56 g NOx s−1 MW−1). This analysis demonstrates clearly that there are biome-specific, diurnal, and regional differences in FERs for the dominating types of vegetation burned in the tropics and subtropics. Possible factors affecting the magnitude of the obtained values are discussed.

scholarly journals The empirical relationship between satellite-derived tropospheric NO<sub>2</sub> and fire radiative power and possible implications for fire emission rates of NO<sub>x</sub>

2014 ◽  
Vol 14 (5) ◽  
pp. 2447-2466 ◽  
Author(s):  
S. F. Schreier ◽  
A. Richter ◽  
J. W. Kaiser ◽  
J. P. Burrows
Keyword(s):  
Empirical Relationship ◽  
Fire Intensity ◽  
Burned Area ◽  
Emission Rates ◽  
Monthly Means ◽  
Fire Emissions ◽  
Vegetation Fires ◽  
Radiative Power ◽  
The Tropics ◽  
Fire Radiative Power

Abstract. Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua satellites are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area, on average, globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from the Global Fire Emissions Database (GFEDv3.1) over 5 characteristic biomass burning regions in the tropics and subtropics shows good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28–1.03 g NOx s−1 MW−1) and highest for croplands and woody savannas (0.82–1.56 g NOx s−1 MW−1). This analysis demonstrates that the strong empirical relationship between TVC NO2 and FRP and the following simplified assumptions are a useful tool for the characterization of NOx emission rates from vegetation fires in the tropics and subtropics. Possible factors affecting the magnitude of the obtained values are discussed.

scholarly journals Varying relationships between fire radiative power and fire size at a global scale

2019 ◽  
Vol 16 (2) ◽  
pp. 275-288 ◽  
Author(s):  
Pierre Laurent ◽  
Florent Mouillot ◽  
Maria Vanesa Moreno ◽  
Chao Yue ◽  
Philippe Ciais
Keyword(s):  
Patch Size ◽  
Empirical Relation ◽  
Global Scale ◽  
Fire Season ◽  
Fire Intensity ◽  
Burned Area ◽  
Fire Size ◽  
Fire Emissions ◽  
Radiative Power ◽  
Fire Radiative Power

Abstract. Vegetation fires are an important process in the Earth system. Fire intensity locally impacts fuel consumption, damage to the vegetation, chemical composition of fire emissions and also how fires spread across landscapes. It has been observed that fire occurrence, defined as the frequency of active fires detected by the MODIS sensor, is related to intensity with a hump-shaped empirical relation, meaning that occurrence reaches a maximum at intermediate fire intensity. Raw burned area products obtained from remote sensing can not discriminate between ignition and propagation processes. To go beyond burned area and to test if fire size is driven by fire intensity at a global scale as expected from empirical fire spread models, we used the newly delivered global FRY database, which provides fire patch functional traits based on satellite observation, including fire patch size, and the fire radiative power measures from the MCD14ML dataset. This paper describes the varying relationships between fire size and fire radiative power across biomes at a global scale. We show that in most fire regions of the world defined by the GFED database, the linear relationship between fire radiative power and fire patch size saturates for a threshold of intermediate-intensity fires. The value of this threshold differs from one region to another and depends on vegetation type. In the most fire-prone savanna regions, once this threshold is reached, fire size decreases for the most intense fires, which mostly happen in the late fire season. According to the percolation theory, we suggest that the decrease in fire size for more intense late season fires is a consequence of the increasing fragmentation of fuel continuity throughout the fire season and suggest that landscape-scale feedbacks should be developed in global fire modules.

scholarly journals Assessment of the Characteristics of Recent Major Wildfires in the USA, Australia and Brazil in 2018–2019 Using Multi-Source Satellite Products

2020 ◽  
Vol 12 (11) ◽  
pp. 1803 ◽  
Author(s):  
Mahlatse Kganyago ◽  
Lerato Shikwambana
Keyword(s):  
Forest Cover ◽  
Anthropogenic Activities ◽  
Management Strategies ◽  
Environmental Parameters ◽  
Fuel Load ◽  
Fire Intensity ◽  
Burned Area ◽  
Radiative Power ◽  
The Usa ◽  
Moderate Resolution Imaging Spectroradiometer

This study analysed the characteristics of the recent (2018–2019) wildfires that occurred in the USA, Brazil, and Australia using Moderate Resolution Imaging Spectroradiometer (MODIS) active fires (AF), fire radiative power (FRP, MW) and burned area (BA) products. Meteorological and environmental parameters were also analysed. The study found various patterns in the spatial distribution of fires, FRP and BA at the three sites, associated with various vegetation compositions, prevailing meteorological and environmental conditions and anthropogenic activities. We found significant fire clusters along the western and eastern coasts of the USA and Australia, respectively, while vastly distributed clusters were found in Brazil. Across all sites, significant fire intensity was recorded over forest cover (FC) and shrublands (SL), attributed to highly combustible tree crown fuel load characterised by leafy canopies and thin branches. In agreement, BA over FC was the highest in the USA and Australia, while Brazil was dominated by the burning of SL, characteristic of fire-tolerant Cerrado. The relatively lower BA over FC in Brazil can be attributed to fuel availability and proximity to highly flammable cover types such as cropland, SL and grasslands rather than fuel flammability. Overall, this study contributes to a better understanding of wildfires in various regions and the underlying environmental and meteorological causal factors, towards better wildfire disaster management strategies and habitat-specific firefighting.

Remote classification of head and backfire types from MODIS fire radiative power and smoke plume observations

2005 ◽  
Vol 14 (3) ◽  
pp. 249 ◽  
Author(s):  
Alistair M. S. Smith ◽  
Martin J. Wooster
Keyword(s):  
Front Propagation ◽  
Pollutant Emissions ◽  
Radiative Energy ◽  
Burned Area ◽  
Remote Measurement ◽  
Radiative Power ◽  
Flaming Combustion ◽  
Order Of Magnitude ◽  
Fire Radiative Power

The classification of savanna fires into headfire and backfire types can in theory help in assessing pollutant emissions to the atmosphere via relative apportionment of the amounts of smouldering and flaming combustion occurring, and is also important when assessing a fire’s ecological effects. This paper provides a preliminary assessment of whether a combination of visible and thermal satellite remote sensing can be used to classify fires into head and backfire categories. Remote determination of the fire radiative power, alongside assessments of the prevailing direction of the wind (through identification of the fire-related smoke plumes) and the fire front propagation (through its relation to the previously burned area) were used to infer the fire type category and to calculate ‘radiative’ fireline intensity (FLI). The ratio of radiative FLI for the head and backfire categories was found similar to that of in situ fireline intensity measurements, but the magnitudes of the radiative FLI values were around an order of magnitude lower. This agrees with other data suggesting that a fire’s radiative energy is around an order of magnitude lower than the fuel’s theoretical heat yield, and suggests that the remote measurement of radiative FLI and classification of headfire and backfire types is a realistic proposition for large wildfire activity.

Estimation of Byram’s Fire Intensity and Rate of Spread from Spaceborne Remote Sensing Data in a Savanna Landscape

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 65
Author(s):  
Gernot Ruecker ◽  
David Leimbach ◽  
Joachim Tiemann
Keyword(s):  
Remote Sensing ◽  
Fuel Consumption ◽  
Spatial Resolution ◽  
Fire Behavior ◽  
Remote Sensing Data ◽  
Fire Intensity ◽  
Rate Of Spread ◽  
Radiative Power ◽  
Sentinel 2 ◽  
Fire Radiative Power

Fire behavior is well described by a fire’s direction, rate of spread, and its energy release rate. Fire intensity as defined by Byram (1959) is the most commonly used term describing fire behavior in the wildfire community. It is, however, difficult to observe from space. Here, we assess fire spread and fire radiative power using infrared sensors with different spatial, spectral and temporal resolutions. The sensors used offer either high spatial resolution (Sentinel-2) for fire detection, but a low temporal resolution, moderate spatial resolution and daily observations (VIIRS), and high temporal resolution with low spatial resolution and fire radiative power retrievals (Meteosat SEVIRI). We extracted fire fronts from Sentinel-2 (using the shortwave infrared bands) and use the available fire products for S-NPP VIIRS and Meteosat SEVIRI. Rate of spread was analyzed by measuring the displacement of fire fronts between the mid-morning Sentinel-2 overpasses and the early afternoon VIIRS overpasses. We retrieved FRP from 15-min Meteosat SEVIRI observations and estimated total fire radiative energy release over the observed fire fronts. This was then converted to total fuel consumption, and, by making use of Sentinel-2-derived burned area, to fuel consumption per unit area. Using rate of spread and fuel consumption per unit area, Byram’s fire intensity could be derived. We tested this approach on a small number of fires in a frequently burning West African savanna landscape. Comparison to field experiments in the area showed similar numbers between field observations and remote-sensing-derived estimates. To the authors’ knowledge, this is the first direct estimate of Byram’s fire intensity from spaceborne remote sensing data. Shortcomings of the presented approach, foundations of an error budget, and potential further development, also considering upcoming sensor systems, are discussed.

scholarly journals Current Trend of Carbon Emissions from Wildfires in Siberia

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 559
Author(s):  
Evgenii Ponomarev ◽  
Nikita Yakimov ◽  
Tatiana Ponomareva ◽  
Oleg Yakubailik ◽  
Susan G. Conard
Keyword(s):  
Carbon Emissions ◽  
Current Trend ◽  
Fire Season ◽  
Fire Intensity ◽  
Fire Emissions ◽  
Active Fire ◽  
Radiative Power ◽  
Annual Carbon ◽  
Global Carbon ◽  
Fire Radiative Power

Smoke from wildfires in Siberia often affects air quality over vast territories of the Northern hemisphere during the summer. Increasing fire emissions also affect regional and global carbon balance. To estimate annual carbon emissions from wildfires in Siberia from 2002–2020, we categorized levels of fire intensity for individual active fire pixels based on fire radiative power data from the standard MODIS product (MOD14/MYD14). For the last two decades, estimated annual direct carbon emissions from wildfires varied greatly, ranging from 20–220 Tg C per year. Sporadic maxima were observed in 2003 (>150 Tg C/year), in 2012 (>220 Tg C/year), in 2019 (~180 Tg C/year). However, the 2020 fire season was extraordinary in terms of fire emissions (~350 Tg C/year). The estimated average annual level of fire emissions was 80 ± 20 Tg C/year when extreme years were excluded from the analysis. For the next decade the average level of fire emissions might increase to 250 ± 30 Tg C/year for extreme fire seasons, and to 110 ± 20 Tg C/year for moderate fire seasons. However, under the extreme IPCC RPC 8.5 scenario for Siberia, wildfire emissions might increase to 1200–1500 Tg C/year by 2050 if there were no significant changes in patterns of vegetation distribution and fuel loadings.

Southern African fire regimes as revealed by remote sensing

2010 ◽  
Vol 19 (7) ◽  
pp. 861 ◽  
Author(s):  
S. Archibald ◽  
R. J. Scholes ◽  
D. P. Roy ◽  
G. Roberts ◽  
L. Boschetti
Keyword(s):  
Southern Africa ◽  
Human Activities ◽  
Spatial Information ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Intensity ◽  
Fire Size ◽  
Regional Patterns ◽  
Radiative Power ◽  
Fire Radiative Power

Here we integrate spatial information on annual burnt area, fire frequency, fire seasonality, fire radiative power and fire size distributions to produce an integrated picture of fire regimes in southern Africa. The regional patterns are related to gradients of environmental and human controls of fire, and compared with findings from other grass-fuelled fire systems on the globe. The fire regime differs across a gradient of human land use intensity, and can be explained by the differential effect of humans on ignition frequencies and fire spread. Contrary to findings in the savannas of Australia, there is no obvious increase in fire size or fire intensity from the early to the late fire season in southern Africa, presumably because patterns of fire ignition are very different. Similarly, the importance of very large fires in driving the total annual area burnt is not obvious in southern Africa. These results point to the substantial effect that human activities can have on fire in a system with high rural population densities and active fire management. Not all aspects of a fire regime are equally impacted by people: fire-return time and fire radiative power show less response to human activities than fire size and annual burned area.

scholarly journals Forecasting the regional fire radiative power for regularly ignited vegetation fires

2021 ◽  
Author(s):  
Tero M. Partanen ◽  
Mikhail Sofiev
Keyword(s):  
Remote Sensing ◽  
Meteorological Data ◽  
Grid Cell ◽  
Radiative Energy ◽  
Fire Intensity ◽  
High Temporal Resolution ◽  
South Central ◽  
Radiative Power ◽  
Cloud Mask ◽  
Fire Radiative Power

Abstract. This paper presents a phenomenological framework for forecasting the area-integrated fire radiative power from wildfires. In the method, a region of interest is covered with a regular grid, which cells are uniquely and independently parameterized with regard to the fire intensity according to (i) the fire incidence history, (ii) the retrospective meteorological information, and (iii) remotely-sensed high temporal resolution fire radiative power taken together with (iv) consistent cloud mask data. The parameterization is realized by fitting the predetermined functions for diurnal and annual profiles of fire radiative power to the remote-sensing observations. After the parametrization, the input for the fire radiative power forecast is the meteorological data alone, i.e., the weather forecast. The method is tested retrospectively for south-central African savannah areas with grid cell size of 1.5° × 1.5°. The input data included ECMWF ERA5 meteorological reanalysis and SEVIRI/MSG Fire Radiative Power and Cloud Mask. It has been found that in the areas with large numbers of wildfires regularly ignited on a daily basis during dry seasons from year to year, the temporal fire radiative power evolution is quite predictable, whereas the areas with irregular fire behaviour predictability was low. The predictive power of the method is demonstrated by comparing the predicted fire radiative power patterns and fire radiative energy values against the corresponding remote-sensing observations. The current method showed good skills for the considered African regions and was useful in understanding the challenges in predicting the wildfires in a more general case.

scholarly journals Fire Detection and Fire Radiative Power in Forests and Low-Biomass Lands in Northeast Asia: MODIS versus VIIRS Fire Products

2020 ◽  
Vol 12 (18) ◽  
pp. 2870
Author(s):  
Yuyun Fu ◽  
Rui Li ◽  
Xuewen Wang ◽  
Yves Bergeron ◽  
Osvaldo Valeria ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Northeast Asia ◽  
Fire Detection ◽  
Fire Regimes ◽  
Burned Area ◽  
Commission Errors ◽  
Fire Emissions ◽  
Radiative Power ◽  
Moderate Resolution ◽  
Fire Radiative Power

Fire omission and commission errors, and the accuracy of fire radiative power (FRP) from satellite moderate-resolution impede the studies on fire regimes and FRP-based fire emissions estimation. In this study, we compared the accuracy between the extensively used 1-km fire product of MYD14 from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the 375-m fire product of VNP14IMG from the Visible Infrared Imaging Radiometer Suite (VIIRS) in Northeastern Asia using data from 2012–2017. We extracted almost simultaneous observation of fire detection and FRP from MODIS-VIIRS overlapping orbits from the two fire products, and identified and removed duplicate fire detections and corresponding FRP in each fire product. We then compared the performance of the two products between forests and low-biomass lands (croplands, grasslands, and herbaceous vegetation). Among fire pixels detected by VIIRS, 65% and 83% were missed by MODIS in forests and low-biomass lands, respectively; whereas associated omission rates by VIIRS for MODIS fire pixels were 35% and 53%, respectively. Commission errors of the two fire products, based on the annual mean measurements of burned area by Landsat, decreased with increasing FRP per fire pixel, and were higher in low-biomass lands than those in forests. Monthly total FRP from MODIS was considerably lower than that from VIIRS due to more fire omission by MODIS, particularly in low-biomass lands. However, for fires concurrently detected by both sensors, total FRP was lower with VIIRS than with MODIS. This study contributes to a better understanding of fire detection and FRP retrieval performance between MODIS and its successor VIIRS, providing valuable information for using those data in the study of fire regimes and FRP-based fire emission estimation.

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