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| Titel |
Multi-scale influence of vapor pressure deficit on fire ignition and spread in boreal forest ecosystems |
| VerfasserIn |
F. Sedano, J. T. Randerson |
| 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 ; 11, no. 14 ; Nr. 11, no. 14 (2014-07-18), S.3739-3755 |
| Datensatznummer |
250117515
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| Publikation (Nr.) |
 copernicus.org/bg-11-3739-2014.pdf |
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| Zusammenfassung |
| Climate-driven changes in the fire regime within boreal forest ecosystems
are likely to have important effects on carbon cycling and species
composition. In the context of improving fire management options and
developing more realistic scenarios of future change, it is important to
understand how meteorology regulates different aspects of fire dynamics,
including ignition, daily fire spread, and cumulative annual burned area.
Here we combined Moderate-Resolution Imaging Spectroradiometer (MODIS) active fires (MCD14ML), MODIS imagery (MOD13A1) and
ancillary historic fire perimeter information to produce a data set of daily
fire spread maps for Alaska during 2002–2011. This approach provided a
spatial and temporally continuous representation of fire progression and a
precise identification of ignition and extinction locations and dates for
each wildfire. The fire-spread maps were analyzed with daily vapor
pressure deficit (VPD) observations from the North American Regional
Reanalysis (NARR) and lightning strikes from the Alaska Lightning Detection
Network (ALDN). We found a significant relationship between daily VPD and
likelihood that a lightning strike would develop into a fire ignition. In
the first week after ignition, above average VPD increased the probability
that fires would grow to large or very large sizes. Strong relationships
also were identified between VPD and burned area at several levels of
temporal and spatial aggregation. As a consequence of regional coherence in
meteorology, ignition, daily fire spread, and fire extinction events were
often synchronized across different fires in interior Alaska. At a regional
scale, the sum of positive VPD anomalies during the fire season was
positively correlated with annual burned area during the NARR era
(1979–2011; R2 = 0.45). Some of the largest fires we mapped had slow
initial growth, indicating opportunities may exist for suppression efforts
to adaptively manage these forests for climate change. The results of our
spatiotemporal analysis provide new information about temporal and spatial
dynamics of wildfires and have implications for modeling the terrestrial
carbon cycle. |
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