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| Titel |
High-latitude cooling associated with landscape changes from North American boreal forest fires |
| VerfasserIn |
B. M. Rogers, J. T. Randerson, G. B. Bonan |
| 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 ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-01), S.699-718 |
| Datensatznummer |
250017497
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| Publikation (Nr.) |
 copernicus.org/bg-10-699-2013.pdf |
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| Zusammenfassung |
| Fires in the boreal forests of North America are generally stand-replacing,
killing the majority of trees and initiating succession that may last over a
century. Functional variation during succession can affect local surface
energy budgets and, potentially, regional climate. Burn area across Alaska
and Canada has increased in the last few decades and is projected to be
substantially higher by the end of the 21st century because of a warmer
climate with longer growing seasons. Here we simulated changes in forest
composition due to altered burn area using a stochastic model of fire
occurrence, historical fire data from national inventories, and succession
trajectories derived from remote sensing. When coupled to an Earth system
model, younger vegetation from increased burning cooled the high-latitude
atmosphere, primarily in the winter and spring, with noticeable feedbacks
from the ocean and sea ice. Results from multiple scenarios suggest that a
doubling of burn area would cool the surface by 0.23 ± 0.09 °C
across boreal North America during winter and spring months (December through
May). This could provide a negative feedback to winter warming on the order
of 3–5% for a doubling, and 14–23% for a quadrupling, of burn
area. Maximum cooling occurs in the areas of greatest burning, and between
February and April when albedo changes are largest and solar insolation is
moderate. Further work is needed to integrate all the climate drivers from
boreal forest fires, including aerosols and greenhouse gasses. |
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