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Titel |
Impact of 2050 climate change on North American wildfire: consequences for ozone air quality |
VerfasserIn |
X. Yue, L. J. Mickley, J. A. Logan, R. C. Hudman, M. V. Martin, R. M. Yantosca |
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 ; 15, no. 17 ; Nr. 15, no. 17 (2015-09-08), S.10033-10055 |
Datensatznummer |
250120021
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Publikation (Nr.) |
copernicus.org/acp-15-10033-2015.pdf |
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Zusammenfassung |
We estimate future area burned in the Alaskan and Canadian forest by the
mid-century (2046–2065) based on the simulated meteorology from 13 climate
models under the A1B scenario. We develop ecoregion-dependent regressions
using observed relationships between annual total area burned and a suite of
meteorological variables and fire weather indices, and apply these
regressions to the simulated meteorology. We find that for Alaska and
western Canada, almost all models predict significant (p < 0.05)
increases in area burned at the mid-century, with median values ranging from
150 to 390 %, depending on the ecoregion. Such changes are attributed
to the higher surface air temperatures and 500 hPa geopotential heights
relative to present day, which together lead to favorable conditions for
wildfire spread. Elsewhere the model predictions are not as robust. For the
central and southern Canadian ecoregions, the models predict increases in
area burned of 45–90 %. Except for the Taiga Plain, where area burned
decreases by 50 %, no robust trends are found in northern Canada, due to
the competing effects of hotter weather and wetter conditions there. Using
the GEOS-Chem chemical transport model, we find that changes in wildfire
emissions alone increase mean summertime surface ozone levels by 5 ppbv for
Alaska, 3 ppbv for Canada, and 1 ppbv for the western US by the
mid-century. In the northwestern US states, local wildfire emissions at the
mid-century enhance surface ozone by an average of 1 ppbv, while transport of
boreal fire pollution further degrades ozone air quality by an additional
0.5 ppbv. The projected changes in wildfire activity increase daily
summertime surface ozone above the 95th percentile by 1 ppbv in the
northwestern US, 5 ppbv in the high latitudes of Canada, and 15 ppbv in
Alaska, suggesting a greater frequency of pollution episodes in the future
atmosphere. |
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