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Titel |
A decadal satellite analysis of the origins and impacts of smoke in Colorado |
VerfasserIn |
M. Val Martin, C. L. Heald, B. Ford, A. J. Prenni, C. Wiedinmyer |
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 ; 13, no. 15 ; Nr. 13, no. 15 (2013-08-02), S.7429-7439 |
Datensatznummer |
250085602
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Publikation (Nr.) |
copernicus.org/acp-13-7429-2013.pdf |
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Zusammenfassung |
We analyze the record of aerosol optical depth (AOD) measured by the MODerate
resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite in
combination with surface PM2.5 to investigate the impact of fires on
aerosol loading and air quality over Colorado from 2000 to 2012, and to
evaluate the contribution of local versus transported smoke. Fire smoke
contributed significantly to the AOD levels observed over Colorado. During
the worst fire seasons of 2002 and 2012, average MODIS AOD over the Colorado
Front Range corridor were 20–50% larger than the other 11 yr studied.
Surface PM2.5 was also unusually elevated during fire events and
concentrations were in many occasions above the daily National Ambient Air
Quality Standard (35 μg m−3) and even reached locally unhealthy levels
(> 100 μg m−3) over populated areas during the 2012 High
Park fire and the 2002 Hayman fire. Over the 13 yr examined, long-range
transport of smoke from northwestern US and even California (> 1500 km
distance) occurred often and affected AOD and surface PM2.5. During most
of the transport events, MODIS AOD and surface PM2.5 were reasonable
correlated (r2 = 0.2–0.9), indicating that smoke subsided into the
Colorado boundary layer and reached surface levels. However, that is not
always the case since at least one event of AOD enhancement was disconnected
from the surface (r2<0.01 and low PM2.5 levels). Observed plume
heights from the Multi-angle Imaging SpectroRadiometer (MISR) satellite
instrument and vertical aerosol profiles measured by the space-based
Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) showed a complex
vertical distribution of smoke emitted by the High Park fire in 2012. Smoke
was detected from a range of 1.5 to 7.5 km altitude at the fire origin and
from ground levels to 12.3 km altitude far away from the source. The
variability of smoke altitude as well as the local meteorology were key in
determining the aerosol loading and air quality over the Colorado Front Range
region. Our results underline the importance of accurate characterization of
the vertical distribution of smoke for estimating the air quality degradation
associated with fire activity and its link to human health. |
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