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Titel |
Assessment of uncertainties of an aircraft-based mass balance approach for quantifying urban greenhouse gas emissions |
VerfasserIn |
M. O. L. Cambaliza, P. B. Shepson, D. R. Caulton, B. Stirm, D. Samarov, K. R. Gurney, J. Turnbull, K. J. Davis, A. Possolo, A. Karion, C. Sweeney, B. Moser, A. Hendricks, T. Lauvaux, K. Mays, J. Whetstone, J. Huang, I. Razlivanov, N. L. Miles, S. J. Richardson |
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 ; 14, no. 17 ; Nr. 14, no. 17 (2014-09-02), S.9029-9050 |
Datensatznummer |
250118998
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Publikation (Nr.) |
copernicus.org/acp-14-9029-2014.pdf |
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Zusammenfassung |
Urban environments are the primary contributors to global anthropogenic
carbon emissions. Because much of the growth in CO2 emissions will
originate from cities, there is a need to develop, assess, and improve
measurement and modeling strategies for quantifying and monitoring
greenhouse gas emissions from large urban centers. In this study the
uncertainties in an aircraft-based mass balance approach for quantifying
carbon dioxide and methane emissions from an urban environment, focusing on
Indianapolis, IN, USA, are described. The relatively level terrain of
Indianapolis facilitated the application of mean wind fields in the mass
balance approach. We investigate the uncertainties in our aircraft-based
mass balance approach by (1) assessing the sensitivity of the measured flux
to important measurement and analysis parameters including wind speed,
background CO2 and CH4, boundary layer depth, and interpolation
technique, and (2) determining the flux at two or more downwind distances
from a point or area source (with relatively large source strengths such as
solid waste facilities and a power generating station) in rapid succession,
assuming that the emission flux is constant. When we quantify the precision
in the approach by comparing the estimated emissions derived from
measurements at two or more downwind distances from an area or point source,
we find that the minimum and maximum repeatability were 12 and 52%,
with an average of 31%. We suggest that improvements in the experimental
design can be achieved by careful determination of the background
concentration, monitoring the evolution of the boundary layer through the
measurement period, and increasing the number of downwind horizontal
transect measurements at multiple altitudes within the boundary layer. |
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