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| Titel |
Global analysis of radiative forcing from fire-induced shortwave albedo change |
| VerfasserIn |
G. López-Saldaña, I. Bistinas, J. M. C. Pereira |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 2 ; Nr. 12, no. 2 (2015-01-29), S.557-565 |
| Datensatznummer |
250117789
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| Publikation (Nr.) |
 copernicus.org/bg-12-557-2015.pdf |
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| Zusammenfassung |
Land surface albedo, a key parameter to derive Earth's surface energy
balance, is used in the parameterization of numerical weather prediction,
climate monitoring and climate change impact assessments. Changes in albedo
due to fire have not been fully investigated on a continental and global
scale. The main goal of this study, therefore, is to quantify the changes in
instantaneous shortwave albedo produced by biomass burning activities and
their associated radiative forcing.
The study relies on the MODerate-resolution
Imaging Spectroradiometer (MODIS) MCD64A1 burned-area product to create an annual composite of areas
affected by fire and the MCD43C2 bidirectional reflectance distribution function (BRDF) albedo snow-free product to compute a
bihemispherical reflectance time series. The approximate day of burning is used
to calculate the instantaneous change in shortwave albedo. Using the
corresponding National Centers for Environmental Prediction (NCEP) monthly
mean downward solar radiation flux at the surface, the global radiative
forcing associated with fire was computed.
The analysis reveals a mean decrease in shortwave albedo of −0.014
(1σ = 0.017), causing a mean positive radiative forcing of
3.99 Wm−2 (1σ = 4.89) over the 2002–20012 time period in areas
affected by fire. The greatest drop in mean shortwave albedo change occurs in
2002, which corresponds to the highest total area burned (378 Mha) observed
in the same year and produces the highest mean radiative forcing
(4.5 Wm−2).
Africa is the main contributor in terms of burned area, but forests globally give the highest radiative forcing per unit area and thus give detectable
changes in shortwave albedo. The global mean radiative forcing for the whole period studied (~0.0275 Wm−2) shows that the contribution of fires
to the Earth system is not insignificant. |
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