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| Titel |
Measurement of turbulent water vapor fluxes using a lightweight unmanned aerial vehicle system |
| VerfasserIn |
R. M. Thomas, K. Lehmann, H. Nguyen, D. L. Jackson, D. Wolfe, V. Ramanathan |
| 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. 1 ; Nr. 5, no. 1 (2012-01-27), S.243-257 |
| Datensatznummer |
250002319
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| Publikation (Nr.) |
 copernicus.org/amt-5-243-2012.pdf |
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| Zusammenfassung |
| We present here the first application of a lightweight unmanned aerial
vehicle (UAV) system designed to measure turbulent properties and vertical
latent heat fluxes (λE). Such measurements are crucial to improve our
understanding of linkages between surface moisture supply and boundary layer
clouds and phenomena such as atmospheric rivers. The application of UAVs
allows for measurements on spatial scales complimentary to satellite,
aircraft, and tower derived fluxes. Key system components are: a turbulent
gust probe; a fast response water vapor sensor; an inertial navigation
system (INS) coupled to global positioning system (GPS); and a 100 Hz data
logging system. We present measurements made in the continental boundary
layer at the National Aeronautics and Space Administration (NASA) Dryden
Research Flight Facility located in the Mojave Desert. Two flights
consisting of several horizontal straight flux run legs up to ten kilometers
in length and between 330 and 930 m above ground level (m a.g.l.) are
compared to measurement from a surface tower. Surface measured λE ranged from
−53 W m−2 to 41 W m−2, and the application of a Butterworth High Pass
Filter (HPF) to the datasets improved agreement to within +/−12 W m−2
for 86% of flux runs, by removing improperly sampled low frequency flux
contributions. This result, along with power and co-spectral comparisons and
consideration of the differing spatial scales indicates the system is able
to resolve vertical fluxes for the measurement conditions encountered.
Challenges remain, and the outcome of these measurements will be used to
inform future sampling strategies and further system development. |
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