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| Titel |
An operational system for the assimilation of the satellite information on wild-land fires for the needs of air quality modelling and forecasting |
| VerfasserIn |
M. Sofiev, R. Vankevich, M. Lotjonen, M. Prank, V. Petukhov, T. Ermakova, J. Koskinen, J. Kukkonen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 18 ; Nr. 9, no. 18 (2009-09-18), S.6833-6847 |
| Datensatznummer |
250007635
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| Publikation (Nr.) |
 copernicus.org/acp-9-6833-2009.pdf |
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| Zusammenfassung |
| This paper investigates a potential of two remotely sensed wild-land fire
characteristics: 4-μm Brightness Temperature Anomaly (TA) and Fire
Radiative Power (FRP) for the needs of operational chemical transport
modelling and short-term forecasting of atmospheric composition and air
quality. The treatments of the TA and FRP data are presented and a
methodology for evaluating the emission fluxes of primary aerosols
(PM2.5 and total PM) is described. The method does not include the
complicated analysis of vegetation state, fuel load, burning efficiency and
related factors, which are uncertain but inevitably involved in approaches
based on burnt-area scars or similar products. The core of the current
methodology is based on the empirical emission factors that are used to
convert the observed temperature anomalies and fire radiative powers into
emission fluxes. These factors have been derived from the analysis of
several fire episodes in Europe (28.4–5.5.2006, 15.8–25.8.2006 and in August
2008). These episodes were characterised by: (i) well-identified FRP and TA
values, and (ii) available ground-based observations of aerosol
concentrations, and optical thickness for the regions where the contribution
of the fire smoke to the concentrations of PM2.5 was dominant, in
comparison with those of other pollution sources. The emission factors were
determined separately for the forested and grassland areas; in case of
mixed-type land use, an intermediate scaling was assumed. Despite
significant differences between the TA and FRP methodologies, an accurate
non-linear fitting was found between the predictions of these approaches.
The agreement was comparatively weak only for small fires, for which the
accuracy of both products is expected to be low. The applications of the
Fire Assimilation System (FAS) in combination with the dispersion model
SILAM showed that both the TA and FRP products are suitable for the
evaluation of the emission fluxes from wild-land fires. The fire-originated
concentrations of aerosols (PM2.5, PM10, sulphates and nitrates)
and AOD, as predicted by the SILAM model were mainly within a factor of 2–3
compared with the observations. The main challenges of the FAS improvement
include refining of the emission factors globally, determination of the
types of fires (smouldering vs flaming), evaluation of the injection heights
of the plumes, and predicting the temporal evolution of fires. |
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