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| Titel |
Consistency of long-term elemental carbon trends from thermal and optical measurements in the IMPROVE network |
| VerfasserIn |
L.-W. A. Chen, J. C. Chow, J. G. Watson, B. A. Schichtel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 10 ; Nr. 5, no. 10 (2012-10-01), S.2329-2338 |
| Datensatznummer |
250003115
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| Publikation (Nr.) |
 copernicus.org/amt-5-2329-2012.pdf |
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| Zusammenfassung |
| Decreasing trends of elemental carbon (EC) have been reported at US
Interagency Monitoring of PROtected Visual Environments (IMPROVE) network
from 1990 to 2004, consistent with the phase-in of cleaner engines, residential
biomass burning technologies, and prescribed burning practices. EC trends
for the past decade are examined due to an upgrade of IMPROVE carbon
instruments and the thermal/optical analysis protocol since 2005. Filter
reflectance (τR) values measured as part of the carbon analysis were
retrieved from archived data and compared with EC for 65 sites with more
complete records within 2000–2009. EC–τR relationships suggest minor
changes of EC quantified by the original and upgraded instruments for most
IMPROVE samples. EC and τR show universal decreasing trends
across the US. The EC and τR trends are correlated, with national
average downward rates (relative to the 2000–2004 baseline medians) of
4.5% yr−1 for EC and 4.1% yr−1 for τR. The consistency
between independent EC and τR measurements adds to the weight of evidence that
EC reductions are real rather than an artifact of changes to the measurement
process. |
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