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| Titel |
Eddy-covariance flux measurements with a weight-shift microlight aircraft |
| VerfasserIn |
S. Metzger, W. Junkermann, M. Mauder, F. Beyrich, K. Butterbach-Bahl, H. P. Schmid, T. Foken |
| 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. 7 ; Nr. 5, no. 7 (2012-07-19), S.1699-1717 |
| Datensatznummer |
250003009
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| Publikation (Nr.) |
 copernicus.org/amt-5-1699-2012.pdf |
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| Zusammenfassung |
| The objective of this study is to assess the feasibility and quality
of eddy-covariance flux measurements from a weight-shift microlight
aircraft (WSMA). Firstly, we investigate the precision of the wind
measurement (σu,v ≤ 0.09 m s−1,
σw = 0.04 m s−1), the lynchpin of
flux calculations from aircraft. From here, the smallest resolvable
changes in friction velocity (0.02 m s−1), and sensible-
(5 W m−2) and latent (3 W m−2) heat flux are
estimated. Secondly, a seven-day flight campaign was performed near
Lindenberg (Germany). Here we compare measurements of wind,
temperature, humidity and respective fluxes between a tall tower and
the WSMA. The maximum likelihood functional relationship (MLFR)
between tower and WSMA measurements considers the random error in
the data, and shows very good agreement of the scalar averages. The
MLFRs for standard deviations (SDs, 2–34%) and fluxes
(17–21%) indicate higher estimates of the airborne
measurements compared to the tower. Considering the 99.5%
confidence intervals, the observed differences are not significant,
with exception of the temperature SD. The comparison with
a large-aperture scintillometer reveals lower sensible heat flux
estimates at both tower (−40 to −25%) and WSMA
(−25–0%). We relate the observed differences to (i) inconsistencies in the temperature and wind measurement at the tower
and (ii) the measurement platforms' differing abilities to capture
contributions from non-propagating eddies. These findings encourage
the use of WSMA as a low cost and highly versatile flux measurement
platform. |
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