New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations
Accurate near real time fire emissions estimates are required for air quality forecasts. To date, most approaches are based on satellite-derived estimates of fire radiative power (FRP), which can be converted to fire radiative energy (FRE) which is directly related to fire emissions. Uncertainties i...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/15/8831/2015/acp-15-8831-2015.pdf |
| _version_ | 1818545357882130432 |
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| author | N. Andela J. W. Kaiser G. R. van der Werf M. J. Wooster |
| author_facet | N. Andela J. W. Kaiser G. R. van der Werf M. J. Wooster |
| author_sort | N. Andela |
| collection | DOAJ |
| description | Accurate near real time fire emissions estimates are required for air
quality forecasts. To date, most approaches are based on satellite-derived
estimates of fire radiative power (FRP), which can be converted to fire
radiative energy (FRE) which is directly related to fire emissions.
Uncertainties in these FRE estimates are often substantial. This is for a
large part because the most often used low-Earth orbit satellite-based
instruments such as the Moderate Resolution Imaging Spectroradiometer
(MODIS) have a relatively poor sampling of the usually pronounced fire
diurnal cycle. In this paper we explore the spatial variation of this fire
diurnal cycle and its drivers using data from the geostationary Meteosat
Spinning Enhanced Visible and Infrared Imager (SEVIRI). In addition, we
sampled data from the SEVIRI instrument at MODIS detection opportunities to
develop two approaches to estimate hourly FRE based on MODIS active fire
detections. The first approach ignored the fire diurnal cycle, assuming
persistent fire activity between two MODIS observations, while the second
approach combined knowledge on the climatology of the fire diurnal cycle
with active fire detections to estimate hourly FRE. The full SEVIRI
time series, providing full coverage of the fire diurnal cycle, were used to
evaluate the results. Our study period comprised of 3 years
(2010–2012), and we focused on Africa and the Mediterranean basin to avoid
the use of potentially lower quality SEVIRI data obtained at very far
off-nadir view angles. We found that the fire diurnal cycle varies
substantially over the study region, and depends on both fuel and weather
conditions. For example, more "intense" fires characterized by a fire
diurnal cycle with high peak fire activity, long duration over the day, and
with nighttime fire activity are most common in areas of large fire size
(i.e., large burned area per fire event). These areas are most prevalent in
relatively arid regions. Ignoring the fire diurnal cycle generally resulted
in an overestimation of FRE, while including information on the climatology
of the fire diurnal cycle improved FRE estimates. The approach based on
knowledge of the climatology of the fire diurnal cycle also improved
distribution of FRE over the day, although only when aggregating model
results to coarser spatial and/or temporal scale good correlation was found
with the full SEVIRI hourly reference data set. We recommend the use of
regionally varying fire diurnal cycle information within the Global Fire
Assimilation System (GFAS) used in the Copernicus Atmosphere Monitoring
Services, which will improve FRE estimates and may allow for further
reconciliation of biomass burning emission estimates from different
inventories. |
| first_indexed | 2024-12-12T07:39:15Z |
| format | Article |
| id | doaj.art-1fdec0759eaf4fd780a47f3c38337fdc |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-12T07:39:15Z |
| publishDate | 2015-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-1fdec0759eaf4fd780a47f3c38337fdc2022-12-22T00:32:50ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242015-08-0115158831884610.5194/acp-15-8831-2015New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observationsN. Andela0J. W. Kaiser1G. R. van der Werf2M. J. Wooster3Faculty of Earth and Life Sciences, VU University, Amsterdam, the NetherlandsMax-Planck-Institut für Chemie, Mainz, GermanyFaculty of Earth and Life Sciences, VU University, Amsterdam, the NetherlandsKings College London, Environmental Monitoring and Modelling Research Group, Department of Geography, London WC2R 2LS, UKAccurate near real time fire emissions estimates are required for air quality forecasts. To date, most approaches are based on satellite-derived estimates of fire radiative power (FRP), which can be converted to fire radiative energy (FRE) which is directly related to fire emissions. Uncertainties in these FRE estimates are often substantial. This is for a large part because the most often used low-Earth orbit satellite-based instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS) have a relatively poor sampling of the usually pronounced fire diurnal cycle. In this paper we explore the spatial variation of this fire diurnal cycle and its drivers using data from the geostationary Meteosat Spinning Enhanced Visible and Infrared Imager (SEVIRI). In addition, we sampled data from the SEVIRI instrument at MODIS detection opportunities to develop two approaches to estimate hourly FRE based on MODIS active fire detections. The first approach ignored the fire diurnal cycle, assuming persistent fire activity between two MODIS observations, while the second approach combined knowledge on the climatology of the fire diurnal cycle with active fire detections to estimate hourly FRE. The full SEVIRI time series, providing full coverage of the fire diurnal cycle, were used to evaluate the results. Our study period comprised of 3 years (2010–2012), and we focused on Africa and the Mediterranean basin to avoid the use of potentially lower quality SEVIRI data obtained at very far off-nadir view angles. We found that the fire diurnal cycle varies substantially over the study region, and depends on both fuel and weather conditions. For example, more "intense" fires characterized by a fire diurnal cycle with high peak fire activity, long duration over the day, and with nighttime fire activity are most common in areas of large fire size (i.e., large burned area per fire event). These areas are most prevalent in relatively arid regions. Ignoring the fire diurnal cycle generally resulted in an overestimation of FRE, while including information on the climatology of the fire diurnal cycle improved FRE estimates. The approach based on knowledge of the climatology of the fire diurnal cycle also improved distribution of FRE over the day, although only when aggregating model results to coarser spatial and/or temporal scale good correlation was found with the full SEVIRI hourly reference data set. We recommend the use of regionally varying fire diurnal cycle information within the Global Fire Assimilation System (GFAS) used in the Copernicus Atmosphere Monitoring Services, which will improve FRE estimates and may allow for further reconciliation of biomass burning emission estimates from different inventories.http://www.atmos-chem-phys.net/15/8831/2015/acp-15-8831-2015.pdf |
| spellingShingle | N. Andela J. W. Kaiser G. R. van der Werf M. J. Wooster New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations Atmospheric Chemistry and Physics |
| title | New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations |
| title_full | New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations |
| title_fullStr | New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations |
| title_full_unstemmed | New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations |
| title_short | New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations |
| title_sort | new fire diurnal cycle characterizations to improve fire radiative energy assessments made from modis observations |
| url | http://www.atmos-chem-phys.net/15/8831/2015/acp-15-8831-2015.pdf |
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